Pregnant women who used cannabis for mental health did not see faster improvement in depression or stress

Depression, stress, and cannabis use all decreased from first to third trimester. 46.8% reported prenatal cannabis use. Those using cannabis for mental health reasons (58.1% of users) had the highest depression scores at each trimester but their rate of decline was statistically equivalent to non-users, suggesting cannabis was not accelerating symptom improvement.

Prospective cohort study of 504 pregnant women recruited at an academic hospital (2019-2024). Depression (Edinburgh Postnatal Depression Scale), stress (Cohen Perceived Stress Scale), and cannabis use assessed each trimester. Cannabis use motives collected in the first trimester. Linear growth curve models estimated trajectories.

Many pregnant women report using cannabis specifically to manage depression and stress. This JAMA Network Open study provides direct evidence that this self-medication strategy is not associated with faster symptom improvement, which could inform clinician counseling.

This study challenges the self-medication rationale that many pregnant cannabis users report. If cannabis is not providing faster depression relief, then the risk-benefit calculation shifts toward recommending evidence-based treatments like therapy or, when appropriate, antidepressants.

Observational design cannot prove cannabis fails to help; it may have unmeasured benefits. Self-reported cannabis use may underestimate actual use. Women with the most severe symptoms may be most likely to use cannabis, creating confounding by indication. No randomization possible.