30-Second Takeaway
- Adolescent cannabis use is strongly associated with later psychotic and bipolar disorders in a large health-system cohort.
- Antidepressant monotherapy in bipolar I disorder increases manic/mixed hospitalization risk, especially in younger adults.
- MST appears as effective as ECT with better cognitive outcomes and more consistent effects across cognitive profiles.
Week ending February 21, 2026
Psychiatry Grand Rounds: Youth Risk, Neuromodulation, and Emerging Personalization
Adolescent cannabis use doubles risk of psychotic and bipolar disorders in a large cohort
Among 463,396 adolescents (13–17 years) in Kaiser Permanente Northern California, 5.7% reported past‑year cannabis use at baseline. Cannabis use was associated with higher risk of incident psychotic disorders (AHR 2.19) and bipolar disorders (AHR 2.01) by age 25. Risks for depressive (AHR 1.34) and anxiety disorders (AHR 1.24) were smaller but still significantly elevated. Associations for depression and anxiety weakened with age, whereas psychosis and bipolar risks remained substantially increased. Findings support routine cannabis screening, explicit risk counseling, and close monitoring for emerging psychotic and mood symptoms in adolescent users.
Antidepressant monotherapy elevates manic and mixed hospitalization risk in bipolar I disorder
This 10‑year Catalonian EHR cohort matched 3,973 bipolar I patients starting antidepressants to 3,973 controls without antidepressants. Overall antidepressant use increased 12‑month hospitalization risk for manic/mixed episodes by about 30% (HR 1.27). Antidepressant monotherapy conferred the highest risk (HR 1.51), whereas antidepressant plus mood stabilizer showed no significant risk increase. Younger adults (18–35) were particularly vulnerable to antidepressant monotherapy (HR 2.36). All antidepressant strategies raised risk more for mixed episodes than pure mania, reinforcing guideline cautions against antidepressant monotherapy.
MST matches ECT efficacy with better cognitive preservation across cognitive profiles
In an open‑label trial, 263 schizophrenia and 135 MDD patients were cognitively profiled, with 54 SCZ and 119 MDD receiving MST or ECT. Both MST and ECT produced significant symptom reductions on PANSS and 24‑item HAM‑D scales. MST yielded better cognitive outcomes, particularly in information processing speed on the MATRICS battery. ECT response varied by baseline cognition, with optimal‑cognition SCZ and poor‑cognition MDD groups showing greatest symptom gains. MST effects were relatively consistent across cognitive profiles, supporting it as a cognitively safer, predictable alternative where available.
References
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Additional Reads
Optional additional studies from this edition.