People with schizophrenia and lifetime cannabis use showed greater deficits in emotional expression and anticipating pleasure

Compared to non-using schizophrenia patients (n=36), those with lifetime cannabis use (n=35) expressed less ability to express emotions, were less likely to anticipate pleasure, and had poorer social functioning. Cannabis use moderated the relationship between anticipatory pleasure and prosocial activities, suggesting cannabis disrupts the motivational pathway from expecting reward to engaging socially.

Cross-sectional comparison of 71 adults with schizophrenia (35 with lifetime cannabis use, 36 without) using the Emotional Expressivity Scale, Temporal Experience of Pleasure Scale, and Social Functioning Scale.

Negative symptoms (flat affect, anhedonia) are the most treatment-resistant aspect of schizophrenia. Finding that cannabis use history worsens these specific deficits suggests cannabis may undermine the very emotional capacities patients need for recovery.

Cannabis is often used by schizophrenia patients to self-medicate. The irony is that while it may temporarily relieve distress, lifetime use appears associated with worsened negative symptoms, the very symptoms that most limit long-term functioning and quality of life.

Cross-sectional (cannot determine causation); small groups; lifetime use measure does not capture current use, dose, or duration; groups may differ on unmeasured variables; prolonged illness duration in both groups.