What is the treatment for marijuana-induced psychosis?

Treatment of Marijuana-Induced Psychosis

Marijuana-induced psychosis should be treated with low-dose atypical antipsychotics (risperidone 2 mg/day or olanzapine 7.5-10 mg/day) combined with immediate cannabis cessation, family psychoeducation, and close monitoring for progression to schizophrenia-spectrum disorders. 1, 2

Immediate Management

Cannabis Cessation

• Complete and immediate cessation of cannabis use is the cornerstone of treatment 2, 3
• Cannabis withdrawal should be conducted in a supportive environment with symptomatic management for agitation and sleep disturbance, though no FDA-approved medications exist specifically for cannabis withdrawal 4
• Be aware that withdrawal symptoms (irritability, insomnia, headaches, anxiety) typically manifest within days of cessation but psychotic symptoms from cannabis use itself are more common than psychotic symptoms from withdrawal 4, 5

Pharmacological Treatment

• Start with low-dose atypical antipsychotics: risperidone 2 mg/day or olanzapine 7.5-10 mg/day 1
• Use a "start low, go slow" approach to minimize side-effects and encourage adherence 1
• Avoid extrapyramidal side-effects as these significantly reduce future medication adherence 1
• If using typical antipsychotics, maximum dose should be 4-6 mg haloperidol equivalent, though atypicals are preferred even at low doses 1

Setting of Care

• Provide treatment in outpatient or home settings whenever possible to avoid the trauma and stigma of hospitalization 1
• Inpatient care is required only if there is significant risk of self-harm, aggression, insufficient community support, or crisis too severe for family management 1

Critical Monitoring Period

Risk of Progression to Schizophrenia

• 44.5% of patients with cannabis-induced psychosis develop schizophrenia-spectrum disorders, often with delayed onset 6
• 47.1% of these patients receive their schizophrenia diagnosis more than one year after the initial cannabis-induced psychotic episode 6
• Young males are at highest risk for progression to persistent psychotic disorders 6
• Patients who progress to schizophrenia develop it at significantly younger ages (males 24.6 years, females 28.9 years) compared to those without prior cannabis-induced psychosis 6

Duration of Monitoring

• Maintain intensive biopsychosocial care for at least 18 months, with the critical period extending up to 5 years 1
• Ensure continuity with the same treating clinician for at least the first 18 months 1
• Monitor for relapse, which occurs in approximately 80% of patients with early psychosis during the first few years 1

Psychosocial Interventions

Family Involvement

• Include families immediately in assessment and treatment planning, as they are typically in crisis and require emotional support and practical advice 1
• Progressively educate family members about the nature of psychosis, treatment options, and expected outcomes 1
• Implement family therapy when there is high family distress 1
• Frame the discussion around psychosis as a chronic but treatable condition, similar to diabetes 1

Patient Education

• Engage in open, non-judgmental conversations about cannabis use 2
• Emphasize that high-THC products (concentrations increased from 9% in 2008 to 17% in 2017, with concentrates reaching 70%) significantly elevate psychosis risk 1, 2
• Discuss that early marijuana use is associated with elevated risk for developing cannabis use disorder and psychotic disorders in adulthood 1

Treatment Failure Protocol

If Symptoms Persist

• If positive psychotic symptoms persist after approximately 12 weeks of first-line atypical antipsychotic treatment, review reasons for treatment failure 1
• Consider non-adherence, continued cannabis use, inadequate dosing, or misdiagnosis 1
• Trial a second atypical antipsychotic before considering other options 1

Behavioral Interventions

• Offer short-duration psychosocial support modeled on motivational principles as initial treatment in non-specialized settings 4
• Refer to specialized treatment for individuals who do not respond to short-duration psychological support 4
• Avoid relying solely on short-term interventions for severe cases 4

Critical Pitfalls to Avoid

• Do not assume cannabis-induced psychosis is benign or self-limited - 77.2% develop new psychotic episodes of any type during follow-up 6
• Do not use dexamphetamine for treatment of cannabis use disorder 4
• Do not overlook physical illnesses that can cause psychosis before initiating antipsychotic treatment 1
• Do not delay treatment until crisis develops (self-harm, violence) - early intervention prevents these outcomes 1
• Do not underestimate the importance of complete cannabis abstinence - ongoing use worsens clinical outcomes including decreased medication adherence and more frequent hospitalizations 3