Anxiety disorder induced by unknown or unspecified psychoactive substance

Essential (Required) Features:

• The presentation is characterized by anxiety symptoms (e.g., apprehension or worry, fear, physiological symptoms of excessive autonomic arousal, panic attacks, avoidance behaviour) that develop during or soon after intoxication with or withdrawal from unknown or unspecified psychoactive substances.
• The intensity or duration of the anxiety symptoms is substantially in excess of anxiety symptoms that are characteristic of Unknown or Unspecified Psychoactive Substance Intoxication or Unknown or Unspecified Psychoactive Substance Withdrawal.
• The symptoms are not better accounted for by another mental disorder such as an Anxiety or Fear-Related Disorder, a Depressive Disorder with prominent anxiety symptoms, or Post-Traumatic Stress Disorder. Evidence supporting a diagnosis of another mental disorder would include anxiety symptoms preceding the onset of unknown or unspecified psychoactive substance use, the symptoms persisting for a substantial period of time after cessation of unknown or unspecified psychoactive substances or withdrawal (e.g., 1 month or more), or other evidence of a pre-existing mental disorder with anxiety symptoms (e.g., a history of prior episodes not associated with unknown or unspecified psychoactive substance use).
• The symptoms are not a manifestation of another medical condition.
• The symptoms cause significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning.

When making a diagnosis of Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances, an additional diagnosis indicating the related pattern of unknown or unspecified psychoactive substance use should also be assigned. These include Episode of Harmful Use of Unknown or Unspecified Psychoactive Substances, Harmful Pattern of Use of Unknown or Unspecified Psychoactive Substances, and Unknown or Unspecified Psychoactive Substance Dependence. A diagnosis of Unknown or Unspecified Psychoactive Substance Intoxication or Unknown or Unspecified Psychoactive Substance Withdrawal may also be assigned if applicable.

Additional Clinical Features:

• Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances may present with patterns of symptoms, depending on the specific substance used, that vary according to the characteristics of the user (e.g., genetics, metabolism, personality factors). Unknown or Unspecified Psychoactive Substances use in higher amounts or over longer periods of time is more likely to be associated with the development of an Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances.
• Symptoms of Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances usually resolve or improve after sustained cessation of unknown or unspecified psychoactive substance use.
• The duration of Substance Withdrawal for some substances can be protracted. For substances with more protracted withdrawal periods, the onset of symptoms of Substance-Induced Anxiety Disorder can occur up to several weeks after the cessation of substance use. Substance-Induced Anxiety Disorder symptoms related to substances with more protracted withdrawal periods may also last for correspondingly longer periods of time.
• In cases in which multiple psychoactive substance are used, it is often challenging to distinguish which substance is the cause of the Substance-Induced Anxiety Disorder. When the specific etiological substance cannot be determined, a diagnosis of Substance-Induced Anxiety Disorder Due to Unknown or Unspecified Psychoactive Substances including Medications may assigned. In cases of multiple psychoactive substance use in which more than one specific substance can be identified as a cause of the Substance-Induced Anxiety Disorder, the corresponding specific Substance-Induced Anxiety Disorder diagnoses should be given instead.

Boundary with Normality (Threshold):

• Symptoms of Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substancess should be differentiated from transient physiological aftereffects of intoxication (‘hangover effect’). The duration or severity of the symptoms in Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substancess must be in excess of ‘hangover effects’ of Unknown or Unspecified Psychoactive Substances and result in significant distress or impairment of functioning.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Unknown or Unspecified Psychoactive Substance Intoxication and Unknown or Unspecified Psychoactive Substance Withdrawal: Mental or behavioural symptoms that occur during Unknown or Unspecified Psychoactive Substance Intoxication or Unknown or Unspecified Psychoactive Substance Withdrawal should only be used as a basis for diagnosing an Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances if the intensity or duration of the symptoms is substantially in excess of those that are characteristic of Unknown or Unspecified Psychoactive Substance Intoxication or Unknown or Unspecified Psychoactive Substance Withdrawal and the symptoms are sufficiently severe to warrant specific clinical attention.
• Boundary with Episode of Harmful Use of Unknown or Unspecified Psychoactive Substances, Harmful Pattern of Use of Unknown or Unspecified Psychoactive Substances, or Unknown or Unspecified Psychoactive Substance Dependence: The impact of repeated or continuous use of unknown or unspecified psychoactive substances characteristic of Harmful Pattern of Use of Unknown or Unspecified Psychoactive Substances and Unknown or Unspecified Psychoactive Substances Dependence may include Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances. Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substancess can also be associated with a single episode of unknown or unspecified psychoactive substance use. In such cases, an Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances should be diagnosed together with a primary diagnosis of Episode of Harmful Use of Unknown or Unspecified Psychoactive Substances, Harmful Pattern of Use of Unknown or Unspecified Psychoactive Substances, or Unknown or Unspecified Psychoactive Substance Dependence.
• Boundary with mental disorders not induced by unknown or unspecified psychoactive substances: Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substancess are differentiated from mental disorders with similar features that are not induced by unknown or unspecified psychoactive substances on the basis of their onset, course and clinical features. A diagnosis of Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances requires evidence from history, physical or mental examination, or laboratory findings of recent unknown or unspecified psychoactive substance use, intoxication or withdrawal. Most Unknown or Unspecified Psychoactive Substance-Induced Mental Disorders resolve or improve within several weeks of cessation of unknown or unspecified psychoactive substance use. Mental disorders not induced by unknown or unspecified psychoactive substances may precede the onset of unknown or unspecified psychoactive substance use or may continue to be symptomatic during periods of sustained abstinence. The co-occurrence of unknown or unspecified psychoactive substance use or withdrawal and onset of symptoms of mental disorders should not be taken as evidence for a presumptive diagnosis of an Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances. Some people use substances to suppress symptoms of mental disorders (e.g., Schizophrenia and Other Primary Psychotic Disorders, Mood Disorders, Anxiety and Fear-Related Disorders, Personality Disorders) and full symptomatic presentations only emerge upon cessation or reduction in substance use. Furthermore, unknown or unspecified psychoactive substance use can exacerbate symptoms or precipitate an episode of a pre-existing mental disorder. Finally, unknown or unspecified psychoactive substance use may be associated with but not aetiologic for new onset of symptoms of a mental disorder. Although a diagnosis of an Anxiety Disorder Induced by Unknown or Unspecified Psychoactive Substances should not be assigned under these circumstances, an additional diagnosis of Episode of Harmful Use of Unknown or Unspecified Psychoactive Substances, Harmful Pattern of Use of Unknown or Unspecified Psychoactive Substances, or Unknown or Unspecified Psychoactive Substance Dependence may still be appropriate.