Disorders due to use of nicotine

Description

Disorders due to use of nicotine are characterised by the pattern and consequences of nicotine use. Nicotine is the active dependence-producing constituent of the tobacco plant, Nicotiana tabacum. Nicotine is used overwhelmingly through smoking cigarettes. Increasingly, it is also used in electronic cigarettes that vaporize nicotine dissolved in a carrier solvent for inhalation (i.e., “vaping”). Pipe smoking, chewing tobacco and inhaling snuff are minor forms of use. Nicotine is a highly potent addictive compound and is the third most common psychoactive substance used worldwide after caffeine and alcohol. Nicotine Dependence and Nicotine Withdrawal are well described and Nicotine-Induced Mental Disorders are recognized. [1]

Diagnostic requirements

WHO clinical descriptions and diagnostic requirements [1,2].

Subcategories

• 6C4A.0 Episode of harmful use of nicotine

  An episode of nicotine use that has caused damage to a person’s physical or mental health. Harm to health of the individual occurs due to one or more of the following: (1) direct or secondary toxic effects on body organs and systems; or (2) a harmful route of administration. This diagnosis should not be made if the harm is attributed to a known pattern of nicotine use. [1]

  Essential (Required) Features:

  • An episode of use of nicotine that has caused clinically significant damage to a person’s physical health or mental health, or has resulted in behaviour leading to harm to the health of others.
  • Harm to health of the individual occurs due to one or more of the following: (1) behaviour related to intoxication; (2) direct or secondary toxic effects on body organs and systems; or (3) a harmful route of administration.
  • Harm to health of others includes any form of physical harm, including trauma, or mental disorder that is directly attributable to behaviour due to Nicotine Intoxication on the part of the person to whom the diagnosis of Episode of Harmful Use of Nicotine applies.
  • Harm to health is not better accounted for by another medical condition or another mental disorder, including another Disorder Due to Substance Use (e.g., Substance Withdrawal).

  Note: Harm to the health of the person to whom the diagnosis applies includes injuries caused by behaviour related to intoxication (e.g., impulsive aggressive behaviour, psychomotor impairment leading to injury), acute health problems resulting from substance use (e.g., overdose, acute gastritis, the effects of hypoxia or prolonged hyperactivity or inactivity), and exacerbation or decompensation of pre-existing chronic health problems (e.g., hypertension, liver disease, or peptic ulceration). Harm may also result from a harmful route of administration (e.g., injecting drug use causing blood-borne virus infections, cocaine use causing a perforated nasal septum). The relevant diagnostic codes from other chapters of the ICD-11, including the chapter on Injury, Poisoning or Certain Other Consequences of External Causes, should be used to describe the specific health consequences of the harmful substance use.

  Harm to the health of others includes any form of physical harm, including trauma (e.g., impaired driving causing a motor vehicle accident, assaultive behaviour leading to bodily harm to another person) or mental disorder (e.g., Post-Traumatic Stress Disorder arising from an assault by the intoxicated individual) that is directly attributable to behaviour due to substance intoxication on the part of the person to whom the diagnosis of Episode of Harmful Psychoactive Substance Use applies.

  Additional Clinical Features:

  • There must be explicit evidence of harm to the individual’s physical or mental health, or of substance-related behaviour due to intoxication that has led to harm to the physical or mental health of others. There must also be a clear causal relationship between the harm to health and the episode of nicotine use in question.
  • The likelihood of harm to self or others due behaviour related to intoxication varies substantially by substance. For example, such behaviour is unlikely to arise from caffeine or nicotine intoxication.
  • Nicotine use commonly occurs in the context of other mental disorders. An additional diagnosis of Episode of Harmful Use of Nicotine can be made if the index episode of nicotine use has resulted in clinically significant harm to the individual’s physical health or has exacerbated or triggered an episode of a pre-existing mental disorder (e.g., a Manic or Depressive Episode or a psychotic episode).
  • A diagnosis of Episode of Harmful Use of Nicotine often signals an opportunity for intervention, typically a low intensity intervention that can be implemented in a wide range of settings that is specifically aimed at reducing the likelihood of additional harmful episodes or of progression to Harmful Pattern of Use or Nicotine Dependence.
  • As more information becomes available indicating that the episode is part of a continuous or recurrent pattern of nicotine use, or if additional harmful episodes occur, a diagnosis of Episode of Harmful Use of Nicotine should be changed to Harmful Pattern of Use of Nicotine or Nicotine Dependence, as appropriate.

  Boundary with Normality (Threshold):

  • The diagnosis of Episode of Harmful Use of Nicotine requires clinically significant harm to the individual’s physical or mental health or that of others. Examples of impact on physical or mental health that would not be considered clinically significant include mild hangover, brief episodes of vomiting, or transient depressed mood.
  • A range of social problems may be associated with an episode of substance use that are not sufficiently severe to constitute clinically significant harm to physical or mental health (e.g., missed appointments, arguments with loved ones). Such problems are not a sufficient basis for a diagnosis of Episode of Harmful Use of Nicotine.

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with Hazardous Nicotine Use: Hazardous Nicotine Use is classified in the chapter on ‘Factors Influencing Health Status or Contact with Health Services’ in the ICD-11 and not in the chapter on Mental, Behavioural, and Neurodevelopmental Disorders. Hazardous Nicotine Use appreciably increases the risk of harmful physical or mental health consequences to the user or to others to an extent that warrants attention and advice from health professionals, but has not resulted in specific identifiable harm and therefore does not meet the diagnostic requirements for Episode of Harmful Use of Nicotine.
  • Boundary with Harmful Pattern of Use of Nicotine: If the harm to health is a result of a known episodic or continuous pattern of substance use and all other diagnostic requirements are met, a diagnosis of Harmful Pattern of Use of Nicotine should be assigned. Substance use is generally considered to be following a pattern if there has been at least episodic or intermittent use over a period of at least 12 months. If harm is caused by use of nicotine but no information is available about the pattern or history of substance use, a diagnosis of Episode of Harmful Use of Nicotine may be assigned until such time as evidence for a pattern of use is ascertained.
  • Boundary with Nicotine Dependence: In Nicotine Dependence, individuals use nicotine persistently despite harm and adverse consequences. Harm caused by such use may be similar to that observed in Episode of Harmful Use of Nicotine. However, Nicotine Dependence also includes additional features of impaired ability to control use and increasing priority given to the substance use over other activities. Physiological features (e.g., tolerance) may also be present. If all diagnostic requirements for Nicotine Dependence are met, Episode of Harmful Use of Nicotine should not be assigned.
  • Boundary with Nicotine Intoxication: Nicotine Intoxication is defined by nicotine use that results in clinically significant transient nicotine-specific symptoms. Recovery from Nicotine Intoxication is generally complete and without physical or mental sequelae. If there is continuing damage or harm (e.g., the effects of hypoxia, the effects of prolonged hyperactivity or inactivity, tissue damage) due to an episode of Nicotine Intoxication, a diagnosis of Episode of Harmful Use of Nicotine may be assigned. If relevant at the time of the clinical encounter (e.g., in emergency settings), Episode of Harmful Use of Nicotine may be diagnosed with an associated diagnosis of Nicotine Intoxication.
  • Boundary with overdose: When ingestion of psychoactive substances results in symptoms of overdose (e.g., coma; life-threatening cardiac or respiratory suppression), a diagnosis from the grouping of Harmful Effects of Substances in the chapter on Injury, Poisoning or Certain Other Consequences of External Causes should also be assigned.
• 6C4A.1 Harmful pattern of use of nicotine

  A pattern of nicotine use that has caused damage to a person’s physical or mental health. The pattern of nicotine use is evident over a period of at least 12 months if substance use is episodic or at least one month if use is continuous (i.e., daily or almost daily). Harm to health of the individual occurs due to one or more of the following: (1) direct or secondary toxic effects on body organs and systems; or (2) a harmful route of administration. [1]

  Essential (Required) Features:

  • A pattern of continuous, recurrent, or sporadic use of nicotine that has caused clinically significant damage to a person’s physical health or mental health (e.g., Nicotine-Induced Mood Disorder), or has resulted in behaviour leading to harm to the health of others.
  • Harm to health of the individual occurs due to one or more of the following: (1) behaviour related to intoxication; (2) direct or secondary toxic effects on body organs and systems; or (3) a harmful route of administration.
  • Harm to health of others includes any form of physical harm, including trauma, or mental disorder that is directly attributable to behaviour related to substance intoxication on the part of the person to whom the diagnosis of Harmful Pattern of Use of Nicotine applies.
  • The pattern of nicotine use is evident over a period of at least 12 months if nicotine use is episodic or at least 1 month if use is continuous.
  • Harm to health is not better accounted for by another medical condition or another mental disorder, including another Disorder Due to Substance Use (e.g., Substance Withdrawal).

  Note: Harm to the health of the person to whom the diagnosis applies includes injuries caused by behaviour related to intoxication (e.g., impulsive aggressive behaviour, psychomotor impairment leading to injury; acute health problems resulting from substance use (e.g., overdose, acute gastritis, the effects of hypoxia or prolonged hyperactivity or inactivity), and exacerbation or decompensation of pre-existing chronic health problems (e.g., hypertension, liver disease, or peptic ulceration). Harm may also result from a harmful route of administration (e.g., injecting drug use causing blood-borne virus infections, cocaine use causing a perforated nasal septum). The relevant diagnostic codes from other chapters of the ICD-11, including the chapter on Injury, Poisoning or Certain Other Consequences of External Causes, should be used to describe the specific health consequences of the harmful substance use.

  Harm to the health of others includes any form of physical harm, including trauma (e.g., impaired driving causing a motor vehicle accident, assaultive behaviour leading to bodily harm to another person) or mental disorder (e.g., Post-Traumatic Stress Disorder arising from an assault by the intoxicated individual) that is directly attributable to behaviour due to substance intoxication on the part of the person to whom the diagnosis of Harmful Pattern of Psychoactive Substance Use applies.

  Course Specifiers:

  A specifier is used to further describe the harmful pattern of substance use, using a fifth-digit code. The fourth-digit code indicates the substance class (i.e., A for nicotine).

  6C4A.10 Harmful Pattern of Use of Nicotine, episodic

  This category is assigned when all the diagnostic requirements for Harmful Pattern of Use of Nicotine are met and there is evidence of a pattern of recurrent episodic or intermittent use of nicotine over a period of at least 12 months that has caused clinically significant harm to a person’s physical or mental health or has resulted in behaviour leading to harm to the health of others.

  6C4A.11 Harmful Pattern of Use of Nicotine, continuous

  This category is assigned when all the diagnostic requirements for Harmful Pattern of Use of Nicotine are met and there is evidence of a pattern of continuous nicotine use (daily or almost daily) over a period of at least 1 month that has caused clinically significant harm to a person’s physical or mental health or has resulted in behaviour leading to harm to the health of others.

  6C4A.1Z Harmful Pattern of Use of Nicotine, unspecified

  Additional Clinical Features:

  • There must be explicit evidence of harm to the individual’s physical or mental health, or of related behaviour due to Nicotine Intoxication that has led to harm to the physical or mental health of others. There must also be a clear causal relationship between the harm to health and the episodic or continuous use of nicotine.
  • The likelihood of harm to self or others due behaviour related to intoxication varies substantially by substance. For example, such behaviour is unlikely to arise from caffeine or nicotine intoxication.
  • As more information becomes available about symptoms and behaviours related to the pattern of nicotine use as well as physiological features indicative of neuroadaptation to the substance, the diagnosis may be changed to Nicotine Dependence if diagnostic requirements are met.

  Boundary with Normality (Threshold):

  • The diagnosis of Harmful Pattern of Use of Nicotine requires clinically significant harm to the individual’s physical or mental health or that of others. Examples of impact on physical or mental health that would not be considered clinically significant include mild hangovers, brief episodes of vomiting, or transient depressed mood.
  • A pattern of nicotine use may cause a range of problems in functioning (e.g., missed appointments, arguments with loved ones) that are not sufficiently severe to constitute clinically significant harm to physical or mental health. Such problems are not a sufficient basis for a diagnosis of Harmful Pattern of Use of Nicotine.

  Developmental Presentations:

  • Harmful Pattern of Use of Nicotine is often a characteristic of late adolescence and young adulthood, and injuries and the consequences of aggressive behaviour are particularly common in this age group.
  • Harmful Pattern of Use of Nicotine in older adults may cause injuries and fractures due to the combination of lowered tolerance, psychomotor impairment induced by a substance, and disorders associated with ageing such as osteoporosis and Dementia.

  Sex- and/or Gender-Related Features:

  • The prevalence of Harmful Pattern of Use of Nicotine is higher in males than females, but the gender differential is smaller in countries where women play a greater role in the workforce. Gender differences in injuries and other forms of harm due to substance use are recognized.

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with Hazardous Use of Nicotine: Hazardous Use of Nicotine is classified in the chapter on ‘Factors Influencing Health Status or Contact with Health Services’ in the ICD-11 and not in the chapter on Mental, Behavioural, and Neurodevelopmental Disorders. Hazardous Use of Nicotine appreciably increases the risk of harmful physical or mental health consequences to the user or to others to an extent that warrants attention and advice from health professionals, but has not resulted in specific identifiable harm and therefore does not meet the diagnostic requirements for Harmful Pattern of Use of Nicotine.
  • Boundary with Episode of Harmful Use of Nicotine: If the harm to health is a result of a single episode of use rather than a pattern of substance use, whether episodic or continuous, a diagnosis of Episode of Harmful Use of Nicotine should be assigned. Nicotine use is generally considered to be following a pattern if there has been at least episodic or intermittent use over a period of at least 12 months. If harm is caused by use of nicotine but no information is available about the pattern or history of nicotine use, a diagnosis of Episode of Harmful Use of Nicotine may be assigned until such time as evidence for a pattern of use is ascertained.
  • Boundary with Nicotine Dependence: In Nicotine Dependence, individuals use nicotine persistently despite harm and adverse consequences. Harm caused by such use may be similar to that observed in Harmful Pattern of Use of Nicotine. However, Nicotine Dependence also includes additional features of impaired ability to control use and increasing priority given to the substance use over other activities. Physiological features (e.g., tolerance) may also be present. If all diagnostic requirements for Nicotine Dependence are met, Harmful Pattern of Use of Nicotine should not be assigned.
  • Boundary with Nicotine Intoxication: Nicotine Intoxication is defined by nicotine use that results in clinically significantly, transient nicotine-specific symptoms. Recovery from Nicotine Intoxication is generally complete and absent of physical or mental sequelae. A pattern or repeated intoxication may or may not result in harm to a person’s physical or mental health or to the health of others. If there is continuing damage or harm as a result of repeated or continuous use of nicotine, a diagnosis of Harmful Pattern of Use of Nicotine may be assigned. If relevant at the time of the clinical encounter (e.g., in an emergency room), Harmful Pattern of Use of Nicotine may be diagnosed with an associated diagnosis of Nicotine Intoxication.
  • Boundary with Nicotine Withdrawal: Nicotine Withdrawal occurs upon cessation or reduction of a substance in the context of physiological dependence or when nicotine has been taken for a prolonged period or in large amounts. Some features of nicotine withdrawal may include physical or mental harm (e.g., depressed or dysphoric mood, bradycardia, increased appetite, anxiety). If the symptoms are entirely explained by the Nicotine Withdrawal, an additional diagnosis of Harmful Pattern of Use of Nicotine is not warranted. However, if the symptoms substantially exceed the expected withdrawal syndrome in duration or type or severity and the diagnostic requirements for Nicotine Dependence are not met, Harmful Pattern of Use of Nicotine can be assigned as the primary diagnosis, with an associated diagnosis of Nicotine Withdrawal.
  • Boundary with other mental disorders and other medical conditions: Numerous mental disorders as well as subthreshold symptoms may co-occur with episodic or continuous patterns of nicotine use. Similarly, continuous or episodic nicotine use increases the risk for mental disorders as well as other medical conditions. Co-occurring mental disorders and comorbid medical conditions should be diagnosed separately, along with a diagnosis of Harmful Pattern of Use of Nicotine.
• 6C4A.2 Nicotine dependence

  Nicotine dependence is a disorder of regulation of nicotine use arising from repeated or continuous use of nicotine. The characteristic feature is a strong internal drive to use nicotine, which is manifested by impaired ability to control use, increasing priority given to use over other activities and persistence of use despite harm or negative consequences. These experiences are often accompanied by a subjective sensation of urge or craving to use nicotine. Physiological features of dependence may also be present, including tolerance to the effects of nicotine, withdrawal symptoms following cessation or reduction in use of nicotine, or repeated use of nicotine or pharmacologically similar substances to prevent or alleviate withdrawal symptoms. The features of dependence are usually evident over a period of at least 12 months but the diagnosis may be made if nicotine use is continuous (daily or almost daily) for at least 3 months. [1]

  Essential (Required) Features:

  • A pattern of recurrent episodic or continuous use of nicotine with evidence of impaired regulation of nicotine use that is manifested by two or more of the following:
    • Impaired control over nicotine use (i.e., onset, frequency, intensity, duration, termination, context);
    • Increasing precedence of nicotine use over other aspects of life, including maintenance of health, and daily activities and responsibilities, such that nicotine use continues or escalates despite the occurrence of harm or negative consequences (e.g., repeated relationship disruption, occupational or scholastic consequences, negative impact on health);
    • Physiological features indicative of neuroadaptation to the substance, including: 1) tolerance to the effects of nicotine or a need to use increasing amounts of nicotine to achieve the same effect; 2) withdrawal symptoms following cessation or reduction in use of nicotine (see Nicotine Withdrawal), or 3) repeated use of nicotine or pharmacologically similar substances to prevent or alleviate withdrawal symptoms.
  • The features of dependence are usually evident over a period of at least 12 months but the diagnosis may be made if use is continuous (daily or almost daily) for at least 3 months.

  Course Specifiers:

  A specifier is also used to describe the pattern of substance use in the context of Nicotine Dependence. Unlike alcohol, separate codes for continuous and episodic current use are not provided.

  6C4A.20 Nicotine Dependence, current use

  Current Nicotine Dependence with episodic or continuous use of nicotine within the past month.

  6C4A.21 Nicotine Dependence, early full remission

  After a diagnosis of Nicotine Dependence and often following a treatment episode or other intervention (including self-help intervention), the individual has been abstinent from nicotine during a period lasting from between 1 and 12 months.

  6C4A.22 Nicotine Dependence, sustained partial remission

  After a diagnosis of Nicotine Dependence, and often following a treatment episode or other intervention (including self-help intervention), there is a significant reduction in nicotine use for more than 12 months, such that even though intermittent or continuous use has occurred during this period, the diagnostic requirements for dependence have not been met.

  6C4A.22 Nicotine Dependence, sustained full remission

  After a diagnosis of Nicotine Dependence, and often following a treatment episode or other intervention (including self-intervention), the person has been abstinent from nicotine for 12 months or longer.

  6C41.2Z Nicotine Dependence, unspecified

  Additional Clinical Features:

  • A subjective sensation of urge or craving to use nicotine often, but not always, accompanies the Essential Features of Nicotine Dependence.
  • When present as an aspect of Nicotine Dependence, withdrawal symptoms must be consistent with the known withdrawal state for nicotine (see Nicotine Withdrawal).
  • Tolerance varies as a function of individual factors (e.g., substance use history, genetics) and should be differentiated from initial levels of response during intoxication, which also exhibit significant individual variability. Laboratory testing that reveals high levels of the substance in bodily fluids with no evidence of significant symptoms of intoxication may be suggestive of tolerance. Tolerance to the effects to substances as indicated by different psychophysiological responses can develop at varying rates (e.g., tolerance to respiratory depression caused by opioid intoxication may develop prior to tolerance to the sedating effects of the drug). With abstinence, tolerance effects diminish over time.
  • Individuals with certain comorbid medical conditions (e.g., chronic liver disease) typically have reduced tolerances to substances.
  • Physical or mental health consequences (beyond the Essential Features of Substance Dependence) typically occur in persons with Substance Dependence but are not required for the diagnosis. Similarly, functional impairment in one or several domains of life (e.g., work, domestic responsibilities, child-rearing) is commonly seen in persons with Substance Dependence, but is not required in order to assign the diagnosis.
  • Individuals with Substance Dependence have elevated rates of many other mental disorders, including Conduct-Dissocial Disorder, Attention Deficit Hyperactivity Disorder, Impulse Control Disorders, Post-Traumatic Stress Disorder, Social Anxiety Disorder, Generalized Anxiety Disorder, Mood Disorders, Psychotic Disorders, and Personality Disorder with prominent dissocial features, as well as subthreshold symptoms. The specific pattern of co-occurrence depends on the specific substance involved, and reflects common risk factors and common causal pathways. These are distinguished from Substance-Induced Mental Disorders, in which the symptoms are a result of the direct physiological effects of the substance on the central nervous system.
  • A pattern of substance use that includes frequent or high dose administration occurs more often among certain subgroups (e.g., adolescents). In these cases, peer group dynamics may contribute to the maintenance of substance use. Regardless of the social contributions to the behaviour, a pattern of substance use that is consistent with subgroup norms should not be considered as presumptive evidence of Substance Dependence unless all diagnostic requirements for the disorder are met.

  Boundary with Normality (Threshold):

  • Frequent or even daily substance use of a nicotine does not automatically imply a diagnosis of Nicotine Dependence. There must also be evidence of the Essential Features of Nicotine Dependence such as impaired control over use, increasing precedence of use over other life priorities, or physiological features.
  • The presence of physiological features such as tolerance and withdrawal is sometimes referred to as ‘physiological dependence’. These features may occur, for example, in response to prolonged therapeutic use of certain medications, such as in patients who are appropriately prescribed opioid analgesics for cancer pain. By themselves, however, these features are not sufficient for a diagnosis of Nicotine Dependence, which also requires either impaired control over substance use or increasing precedence of nicotine use over other activities.

  Course Features:

  • The course of Substance Dependence varies by substance, frequency, intensity, and duration of use. The central features of the dependence syndrome may be overshadowed by the harms to physical and mental health that patients with dependence often experience and for which they frequently seek treatment. Numerous medical conditions can occur due to substance use in the course of Substance Dependence. These conditions tend to be specific for each substance, although some are shared across substances. Negative consequences to physical health reflect either the known pharmacological effects of the relevant substance, the toxic effects of the substance on tissues and organs, or the route of administration (e.g., intravenous self-administration). Examples include alcoholic cirrhosis, infective endocarditis, and HIV/AIDS. Medical conditions caused by substance use should be diagnosed separately.

  Developmental Presentations:

  • Substance Dependence may develop more rapidly during adolescence than is usual during adulthood, especially when there are familial or other risk factors for Substance Dependence.
  • Tolerance to psychoactive substances may develop rapidly in adolescents and young adults, and decline equally rapidly when substance use ceases or is reduced in quantity or frequency.
  • Withdrawal symptoms are well recognized in neonates born to women with Substance Dependence who have used psychoactive substances during pregnancy. However, the presence of a withdrawal state in a neonate should not be the sole basis for a diagnosis of Substance Dependence in the mother.
  • Older adults often have reduced tolerance to substances.

  Sex- and/or Gender-Related Features:

  • Substance Dependence has similar features in men and women, although the intensity of substance use and duration of use necessary to result in dependence may differ by sex.
  • Women are less likely to be involved with the legal system in relation to substance use and therefore may be less likely to come to clinical attention than men. In clinical contexts, women may be reluctant to admit using substances due to prevailing social attitudes and proscriptions.
  • In some societies it may be culturally unacceptable for women to admit to substance use. Specific probing may be necessary to elicit a history of substance use and dependence.

  Boundaries with Other Disorders and with Normality:

  • Boundary with Nicotine Intoxication: Episodic or continuous intoxication with nicotine is a typical feature of Nicotine Dependence, but is not an Essential Feature. Conversely, even if frequent and severe, Nicotine Intoxication alone is not a basis for a diagnosis of Nicotine Dependence. If all diagnostic requirements of both conditions are met for the same episode of care, Nicotine Dependence should be assigned as the primary diagnosis, with an associated diagnosis of Nicotine Intoxication (e.g., Nicotine Dependence with Nicotine Intoxication) if appropriate to the specific clinical situation (e.g., in emergency settings).
  • Boundary with Harmful Use of Nicotine: Nicotine Dependence is often associated with physical and mental health consequences, such as those seen in Harmful Pattern of Use of Nicotine. In the absence of the Essential Features of Nicotine Dependence, a diagnosis of Harmful Use of Nicotine can be given when there has been demonstrable harm to the individual’s physical or mental health or that of others. Harmful Pattern of Use of Nicotine and Nicotine Dependence should not be diagnosed together.
  • Boundary with Nicotine Withdrawal: Many individuals with Nicotine Dependence develop Nicotine Withdrawal upon cessation or reduction in the amount of a nicotine consumed. In such cases, both Nicotine Dependence and Nicotine Withdrawal should be diagnosed. However, Nicotine Withdrawal can be diagnosed in the absence of a diagnosis of Nicotine Dependence.
• 6C4A.3 Nicotine intoxication

  Nicotine intoxication is a clinically significant transient condition that develops during or shortly after the consumption of nicotine that is characterised by disturbances in consciousness, cognition, perception, affect, behaviour, or coordination. These disturbances are caused by the known pharmacological effects of nicotine and their intensity is closely related to the amount of nicotine consumed. They are time-limited and abate as nicotine is cleared from the body. Presenting features may include restlessness, psychomotor agitation, anxiety, cold sweats, headache, insomnia, palpitations, paresthesias, nausea or vomiting, abdominal cramps, confusion, bizarre dreams, burning sensations in the mouth, and salivation. In rare instances, paranoid ideation, perceptual disturbances, convulsions or coma may occur. Nicotine intoxication occurs more commonly in naïve (non-tolerant) users or among those taking higher than accustomed doses. [1]

  Essential (Required) Features:

  • Transient and clinically significant disturbances in consciousness, cognition, perception, affect, behaviour, or coordination that develop during or shortly after the consumption or administration of nicotine.
  • The symptoms must be compatible with the known pharmacological effects of nicotine, and their intensity is closely related to the amount of nicotine consumed.
  • Presenting features of Nicotine Intoxication may include restlessness, psychomotor agitation, anxiety, cold sweats, headache, insomnia, palpitations, paresthesias, nausea or vomiting, abdominal cramps, confusion, bizarre dreams, burning sensations in the mouth, and salivation.
  • The symptoms of intoxication are time-limited and abate as nicotine is cleared from the body.
  • Symptoms are not better accounted for by another medical condition (See below) or another mental disorder, including another Disorder Due to Substance Use (e.g., Withdrawal from a different substance).

  Examples of Medical Conditions That May Present with Symptoms Similar to Substance Intoxication

  • Head injury (with or without cerebral contusion or intracranial haemorrhage or haematoma)
  • Meningitis and encephalitis
  • Diabetic ketoacidosis or hypoglycaemia
  • Hepatic or other metabolic encephalopathy
  • Wernicke’s encephalopathy
  • Electrolyte disturbance
  • Hypoxia or hypercapnia
  • Systemic infection

  Severity of Intoxication Specifier:

  Depending on the specific clinical situation and the information available, Substance Intoxication may be classified according to the level of severity as mild, moderate, or severe. The level of intoxication is usually related to the dose, route of administration, half-life, and duration of action of the substance. Severity of intoxication is also affected by individual variability (e.g., differences in body weight, substance metabolism, or tolerance). Susceptibility to substance intoxication may also be greater in individuals with comorbid medical conditions affecting drug pharmacokinetics (e.g., renal or hepatic insufficiency).

  For some substances, there are specific tests for detecting and determining the concentration of substances in bodily fluids (e.g., blood, urine), which can be important tools for clinical management. However, severity of intoxication should be determined on the basis of clinical assessment, as specified below, and not solely based on the presence and level of the substance in bodily fluids.

  The level of medical attention that may be required in response to substance intoxication varies according to the severity of intoxication and the substance involved, and varies from precautionary observation to urgent intervention to prevent death or permanent harm (e.g., administration of antagonist treatment; intubation).

  The severity of intoxication is classified using the following Extension (X) Codes in addition to the appropriate intoxication category. Extension codes are attached to the category to which they apply using an ampersand (&).

  XS5W Mild

  Mild substance intoxication is a state in which there are clinically recognizable disturbances in psychophysiological functions and responses (e.g., motor coordination, attention and judgement) that vary by substance, but there is little or no disturbance in the level of consciousness.

  The code for Nicotine Intoxication, mild is 6C4A.3&XS5W.

  XS0T Moderate

  Moderate substance intoxication is a state in which there are marked disturbances in psychophysiological functions and responses (e.g., motor coordination, attention and judgement) that vary by substance, with substantial impairment on tasks that require these functions. There is some disturbance in level of consciousness.

  The code for Nicotine Intoxication, moderate is 6C4A.3&XS0T.

  XS25 Severe

  Severe substance intoxication is a state in which there are obvious disturbances in psychophysiological functions and responses (e.g., motor coordination, attention and judgement) that vary by substance, with marked disturbance in level of consciousness. There is severe impairment to the extent that the person may not be capable of self-care or self-protection, and may be unable to communicate or cooperate with assessment and intervention.

  The code for Nicotine Intoxication, severe is 6C4A.3&XS25.

  Additional Clinical Features:

  • Nicotine Intoxication occurs more commonly in people who have recently started smoking or using other forms of nicotine (e.g., electronic cigarettes or ‘vaping’) and have therefore not developed tolerance. It may also occur in persons who receive nicotine therapeutically and take it in higher than recommended doses.
  • In rare instances, paranoid ideation, perceptual disturbances, convulsions, or coma may occur.
  • Psychoactive substances, whether of the same or a different pharmacological class, may interact such that they exacerbate or modify the features of intoxication. In cases of multiple psychoactive substance use in which more than one specific substance can be identified as a cause of the intoxication, it is recommended that the corresponding specific Substance Intoxication categories for each relevant substance be assigned (e.g., 6C40.3 Alcohol Intoxication and 6C4A.3 Nicotine Intoxication) rather than 6C4F.3 Intoxication Due to Multiple Specified Psychoactive Substances.
  • Nicotine Intoxication may occur in the presence of medical conditions that cause impairment of levels of consciousness, cognition, perception, affect, behaviour, or coordination, which should be diagnosed separately. Determination of the aetiology of the disturbances in psychophysiological functions or responses may require longitudinal assessment.

  Boundary with Normality (Threshold):

  • Measurement of the presence or concentration of a substance in breath, blood, saliva, urine or other body fluids may be an important tool in the clinical management of Substance Intoxication. However, detection of a psychoactive substance in body fluids does not constitute a presumptive diagnosis of Substance Intoxication.

  Course Features:

  • The onset of Substance Intoxication varies according to the route of administration, the absorption of the substance and other pharmacokinetic factors. Generally, inhalation (smoking) and intravenous injecting routes lead to more rapid onset of intoxication, though oral ingestion may also lead to intoxication within minutes, depending on the substance.
  • Substance Intoxication is a transient condition, with the duration of intoxication depending on multiple factors including: (1) the dose of the substance taken, (2) the half-life and duration of action of the particular substance, and (3) the formulation of the substance taken (e.g., for pharmaceutical preparations, whether a controlled-release drug has been taken). Intoxication may last from a few minutes up to several days following the episode of use. The intensity of intoxication lessens with time after reaching a peak of absorption, and the effects eventually disappear in the absence of further use of the substance.

  Culture-Related Features:

  • The degree and characteristics of intoxication displayed for a given amount of a psychoactive substance varies considerably with circumstances, with beliefs and expectations about the effects of the substance, and with the cultural acceptability of displaying these effects. These factors result in cultural differences in the extent and manifestations of intoxication.
  • There are also genetic differences in susceptibility to intoxication with specific psychoactive substances associated with certain ethnic groups. Cultural and ethnically linked genetic factors have been better documented for alcohol than for other substances.

  Developmental Presentations:

  • Naïve users including adolescents can show features of intoxication at lower levels of use, reflecting lower physical and learned tolerance.
  • Older adults may have a lower tolerance than younger people to the effects of substances.

  Sex- and/or Gender-Related Features:

  • The amount of substance and duration of use necessary to cause intoxication differs by sex, reflecting differences in body weight and composition.
  • Behaviour while intoxicated may vary by gender, reflecting not only physiological differences, but also cultural differences and role expectations.

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with Episode of Harmful Use of Nicotine and Harmful Pattern of Use of Nicotine: In Episode of Harmful Use of Nicotine and Harmful Pattern of Use of Nicotine, consumption or administration of nicotine results in damage to the person’s physical or mental health (including a Nicotine-Induced Mental Disorder) or in behaviour leading to harm to the health of others. Recovery from Nicotine Intoxication is generally complete. Complications due to such effects of intoxication such as injury, the effects of prolonged hyperactivity or inactivity, or other tissue damage should be diagnosed as Episode of Harmful Use of Nicotine or Harmful Pattern of Use of Nicotine, as appropriate. If relevant at the time of the clinical encounter (e.g., in emergency settings), Nicotine Intoxication can be given as an associated diagnosis, with Episode of Harmful Use of Nicotine or Harmful Pattern of Use of Nicotine as the primary diagnosis.
  • Boundary with Nicotine Dependence: Episodic or continuous intoxication with nicotine is a typical feature of Nicotine Dependence. If all diagnostic requirements of both conditions are met for the same episode of care, Nicotine Dependence should be assigned as the primary diagnosis, with an associated diagnosis of Nicotine Intoxication.
  • Boundary with Nicotine Withdrawal: Nicotine Withdrawal occurs upon cessation or reduction of nicotine in the context of physiological dependence or when nicotine has been taken for a prolonged period or in large amounts. In contrast, the onset of Nicotine Intoxication occurs immediately or shortly after the consumption of nicotine. Moreover the intoxication and withdrawal syndromes for nicotine are typically quite distinct.
  • Boundary with other medical conditions: A variety of medical conditions may produce symptoms that are similar to those of Nicotine Intoxication. Some of these medical conditions are life-threatening requiring immediate intervention. Evidence of nicotine use (e.g., positive laboratory results) does not rule out the possibility of a comorbid medical condition. These alternative diagnoses must be considered in assessing Nicotine Intoxication. Certain medical conditions may also augment or prolong the duration of intoxication. Symptoms of intoxication that persist after they can no longer be reasonably attributed to the pharmacological effects of nicotine may suggest the presence of another medical condition. If it is determined that Nicotine Intoxication is comorbid with a medical condition, both diagnoses should be assigned.
  • Boundary with overdose: When consumption or administration of psychoactive substances results in symptoms of overdose (e.g., coma; life-threatening cardiac or respiratory suppression), it is typically more appropriate to apply a diagnosis from the grouping of Harmful Effects of Substances in the chapter on Injury, Poisoning or Certain Other Consequences of External Causes rather than Substance Intoxication.
• 6C4A.4 Nicotine withdrawal

  Nicotine withdrawal is a clinically significant cluster of symptoms, behaviours and/or physiological features, varying in degree of severity and duration, that occurs upon cessation or reduction of use of nicotine (typically used as a constituent of tobacco) in individuals who have developed Nicotine dependence or have used nicotine for a prolonged period or in large amounts. Presenting features of Nicotine withdrawal may include dysphoric or depressed mood, insomnia, irritability, anger, anxiety, difficulty concentrating, restlessness, bradycardia, increased appetite, and craving for tobacco (or other nicotine-containing products). Other physical symptoms may include increased cough and mouth ulceration. [1]

  Essential (Required) Features:

  • The presence of a clinically significant cluster of symptoms, behaviours, and/or physiological features that occurs upon cessation or reduction in the use of nicotine in individuals who have developed dependence on nicotine or have used nicotine for a prolonged period or in large amounts.
  • Presenting features of Nicotine Withdrawal may include depressed or dysphoric mood, insomnia, irritability, anger, anxiety, difficulty concentrating, restlessness, bradycardia, increased appetite, and craving for tobacco or other nicotine-containing products. Other physical symptoms may include increased cough and mouth ulceration.
  • The severity and duration of Nicotine Withdrawal is variable, related to the amount, frequency and duration of tobacco smoked (or otherwise consumed) or of nicotine products taken prior to cessation of use.
  • The symptoms are not better accounted for by another medical condition or another mental disorder.

  Additional Clinical Features:

  • Onset of Nicotine Withdrawal is typically 6 to 24 hours after cessation or reduction of use. Psychological and physiological features typically last up to 10 days. Physical features such as increased cough and mouth ulceration may persist for 2 to 3 weeks.
  • Craving for tobacco (or other nicotine-containing products) is prominent throughout the duration of Nicotine Withdrawal.
  • Characteristic features of Nicotine Withdrawal are opposite to the acute pharmacological effects of nicotine.
  • Nicotine Withdrawal symptoms become more severe with repeated episodes of withdrawal (termed ‘kindling’), with aging, or in the presence of comorbid medical conditions.

  Boundary with Normality (Threshold):

  • Nicotine Withdrawal should only be diagnosed when symptoms are consistent with those recognized as occurring upon cessation or reduction in use of nicotine. Recent cessation or reduction of use and the presence of various non-specific transient symptoms is not sufficient to make the diagnosis of Nicotine Withdrawal.
  • Withdrawal symptoms should be differentiated from the transient physiological aftereffects of intoxication (‘hangover effect’).
  • Some individuals who have previously had Nicotine Dependence may experience symptoms similar to those of Nicotine Withdrawal months after the last use of the substance, particularly when the individual encounters stimuli (e.g., drug paraphernalia) and contexts (e.g., location where use was frequent) previously associated with past nicotine use. These symptoms are more transient than those observed during Nicotine Withdrawal and occur exclusively when in contact with associated stimuli and contexts. A diagnosis of Nicotine Withdrawal should not be assigned under these circumstances.

  Course Features:

  • Nicotine Withdrawal is time-limited. Factors that influence the features and time course of Nicotine Withdrawal include: (1) the severity of Nicotine Dependence, if present, (2) the dose, frequency of use, and duration of nicotine use prior to cessation or reduction of that use, (3) the half-life and duration of action of nicotine, and (4) the presence of comorbid medical conditions (e.g., metabolic disturbances).

  Culture-Related Features:

  • Symptoms of withdrawal depend largely on the psychotropic characteristics of nicotine. However, specific cultures may emphasize certain symptoms of withdrawal over others, making it more difficult to conduct a differential diagnosis. In addition, vernacular terms for withdrawal vary greatly.

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with Nicotine Dependence: Many individuals with Nicotine Dependence develop Nicotine Withdrawal upon cessation or reduction in the amount of the substance. In such cases, both Nicotine Dependence and Nicotine Withdrawal should be diagnosed. However, Nicotine Withdrawal can be diagnosed in the absence of a diagnosis of Nicotine Dependence.
  • Boundary with Nicotine Intoxication: The onset of Nicotine Intoxication occurs immediately or shortly after the consumption of nicotine. In contrast, Nicotine Withdrawal occurs upon cessation or reduction in the amount of nicotine in the context of Nicotine Dependence or when nicotine has been taken for a prolonged period or in large amounts. For nicotine, the intoxication and withdrawal syndromes are typically distinct.
  • Boundary with other mental disorders: Various symptoms associated with Nicotine Withdrawal overlap with those that are characteristic of other mental disorders (e.g., depressive and anxiety symptoms). Symptoms of Nicotine Withdrawal occur in specific temporal relationship to the cessation of use of nicotine and diminish with the passage of time. Evidence supporting a mental disorder diagnosis would include the symptoms preceding the onset of nicotine use, the symptoms persisting for a substantial period of time after cessation of nicotine or withdrawal (e.g., 1 month or more, depending on the substance), or other evidence of a pre-existing mental disorder (e.g., a history of prior episodes not associated with nicotine use).
  • Boundary with other medical conditions: It may be difficult to distinguish between various symptoms associated with Nicotine Withdrawal (e.g., restlessness, increased appetite, decreased heart rate, sleep disruption) and those that are characteristic of other medical conditions. Symptoms of Nicotine Withdrawal occur in specific temporal relationship to the cessation of use of nicotine and diminish with the passage of time.
  • Boundary with Foetus or Newborn Affected by Maternal Use of Tobacco, Alcohol, or Other Drugs of Addiction: The ICD-11 chapter on Certain Conditions Arising During the Perinatal Period contains categories for ‘Foetus or newborn affected by maternal use of tobacco, alcohol, and other drugs.’ A neonate exhibiting signs of Nicotine Withdrawal may also be Nicotine Withdrawal diagnosis in order to guide treatment together with appropriate diagnosis from the chapter on Certain Conditions Originating in the Perinatal Period.

References

1. World Health Organization. International Classification of Diseases, 11th Revision, for Mortality and Morbidity Statistics (ICD-11 MMS), 2026-01 release. World Health Organization; 2026.
2. World Health Organization. Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders (CDDR). World Health Organization; 2024.

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