Psychiatric and Substance Use Disorders Strongly Predict Cannabis Use During Pregnancy

All psychiatric disorders studied were associated with elevated cannabis use and CUD during pregnancy. Strongest associations for any use: bipolar disorder (aOR 2.83) and tobacco use disorder (aOR 4.03). Strongest associations for CUD: psychotic disorders (aOR 10.01) and stimulant use disorder (aOR 21.99). Anxiety, bipolar, and depressive disorders were associated with daily versus monthly cannabis use.

Observational study of 299,496 pregnancies from 227,555 individuals screened at Kaiser Permanente Northern California from 2011-2021 (excluding 2020). Psychiatric and substance use disorder diagnoses from electronic health records in the two years prior to pregnancy. Cannabis use measured by self-report and urine toxicology at prenatal care entry.

This is the largest study to systematically examine the relationship between mental health conditions and prenatal cannabis use. The finding that virtually every psychiatric and substance use diagnosis increases prenatal cannabis use risk suggests these women may be self-medicating, and that prenatal mental health treatment could indirectly reduce cannabis exposure.

The much stronger associations with substance use disorders than psychiatric disorders suggest that prenatal cannabis use is often part of a broader pattern of substance use rather than isolated self-medication for mental health. This has implications for intervention design: treating one substance in isolation may be insufficient.

Observational design cannot establish whether psychiatric conditions cause cannabis use or vice versa. EHR-based diagnoses may not capture all psychiatric conditions, particularly in mild or undiagnosed cases. Year 2020 was excluded due to pandemic disruptions.