Cannabis‑induced disorder: diagnostic concept

“Cannabis‑induced” disorders are conditions where symptoms (psychosis, mood disturbance, anxiety, sleep problems) develop during or soon after cannabis intoxication or withdrawal, and are judged to be a direct physiological effect of cannabis rather than a primary psychiatric disorder. Temporal relationship, dose/exposure history and recovery trajectory help with diagnosis.

Major types

• Cannabis‑induced psychotic disorder: hallucinations, delusions, disorganised thinking occurring during intoxication or persisting after use.
• Cannabis‑induced anxiety disorder: panic attacks, marked anxiety or panic symptoms temporally linked to cannabis use.
• Cannabis‑induced mood disorder: depressive or manic symptoms triggered by cannabis exposure.
• Cannabis‑induced sleep disorder: insomnia or hypersomnolence emerging with changes in use.
• Other specified/unspecified: cognitive impairment or exacerbation of pre‑existing disorders where cannabis is a major contributing factor.

Clinical features — what to look for

• Temporal link: symptoms start during use or within days of heavy use or cessation.
• High‑potency exposure: concentrates, dabbing, or strong edibles often implicated.
• Severe manifestations: frank psychosis, persistent paranoia, suicidal ideation or dangerous behaviour.
• Age of onset: first episode in adolescence or young adulthood raises concern for cannabis contribution.

Assessment checklist

1. Establish timeline of cannabis exposure (type, potency, route, frequency) and relation to symptom onset.
2. Differentiate intoxication vs persistent disorder: intoxication effects usually resolve hours‑days; persistence beyond a few days warrants further evaluation.
3. Assess for primary psychiatric disorders: family history, prior episodes without cannabis, and symptom pattern.
4. Screen for other substances (stimulants, hallucinogens, alcohol) that can cause similar presentations.
5. Use mental status exam: presence of hallucinations, thought disorder, affective symptoms, and suicidality.
6. Consider basic medical investigations (tox screen where available, metabolic panel) to exclude organic causes.

Management principles

• Immediate safety first: manage agitation, suicidal risk, psychosis or medical instability with standard emergency protocols.
• Remove cannabis exposure: advise cessation and provide brief cessation support; monitor for withdrawal effects.
• Symptomatic pharmacotherapy: short‑term benzodiazepines for severe anxiety (brief, monitored use); antipsychotics for psychosis when indicated (low dose, monitor side effects).
• Psychosocial interventions: CBT for psychosis/anxiety, motivational interviewing for cessation, psychoeducation for patient and family.
• Follow‑up is essential: many cannabis‑induced symptoms resolve but some evolve into chronic disorders—early outpatient or specialist follow‑up recommended within days to weeks.

Treatment specifics by disorder

Cannabis‑induced psychotic disorder

• Acute: ensure safety, consider antipsychotic treatment (risperidone, olanzapine) when hallucinations/delusions cause distress or risk; lowest effective dose.
• Monitor for resolution over 1–4 weeks after cessation; if psychosis persists beyond a month, evaluate for primary psychotic disorder.
• Engage family, reduce cannabis access, and provide psychoeducation about relapse risk with further use.

Cannabis‑induced anxiety disorder

• Short‑term benzodiazepines can control acute panic but use cautiously due to dependence risk.
• Offer CBT for panic/anxiety and relapse‑prevention; consider SSRIs when anxiety persists after abstinence.

Cannabis‑induced mood disorder

• Treat mood symptoms according to severity: antidepressants or mood stabilisers may be indicated if symptoms do not remit with abstinence.
• Watch for bipolarity—cannabis can precipitate mania in vulnerable individuals.

Cannabis‑induced sleep disorder

• Behavioural sleep interventions (CBT‑I, sleep hygiene) are first‑line.
• Short‑term melatonin or hypnotics may be used for severe insomnia with clear exit strategy.

When to refer

• Persistent psychosis beyond several weeks despite abstinence—refer to early psychosis/psychiatry services.
• Severe mood disturbance, suicidality, or inability to care for self—urgent psychiatric care.
• Complex polysubstance use or repeated relapses—specialist addiction services.

Key takeaways

• Identify temporal link between cannabis use and psychiatric symptoms to suspect cannabis‑induced disorder.
• Immediate safety and cessation are priorities; many symptoms remit with abstinence but require monitoring.
• Use symptomatic pharmacotherapy judiciously and provide psychosocial treatments; refer persistent or severe cases to specialist services.