Pandora's Box.

BOX Cannabis, pregnancy and children C has been in the limelight for some time for a variety of reasons, including its medicinal benefits and easing of restrictions on its use in many parts of the world. Public attitudes have relaxed as more powerful drugs attract more attention to their risks. Medicinal use may have influenced public thinking and possible lack of understanding of the versions of cannabis available and the relevance of the THC (delta-9tetrahydrocannabinol) component. In the USA, there has been a dramatic increase in the use of cannabis during pregnancy, which has stimulated interest in examining the possible effects on the offspring of user mothers. Non-clinical evidence shows that THC crosses the placenta and may potentially affect the brain development of the offspring. Researchers had previously found that maternal cannabis use during pregnancy was associated with increased psychopathology in middle childhood. In a recently published study, following up the original data from the ABCD (Adolescent Brain Cognitive Development) study, they examined the possibility that psychopathology persists into early adolescence. Following the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for cohort studies, they used mixed models to estimated associations between retrospective reports of cannabis use in three maternal groups (group 1, cannabis use during pregnancy, before mothers became aware of their pregnancy; group 2, cannabis use both before and after knowledge of pregnancy; and group 3, no exposure to cannabis) and child psychopathology. A total of 10 631 mothers participated in the study, with the following numbers in each group: group 1, n=391; group 2, n= 208; and group 3, n=10 032. Of these, 81% were White, 22% were African American, 7% were Asian or Asian American, 7% were Hispanic, 4% were native American and 7% were other. The researchers assessed children for psychopathology, at baseline and at follow-up after 1 and after 2 years. Cannabis exposure during pregnancy was associated with persisting psychopathology (attention, social and behavioural problems) throughout early adolescence and did not change with age. This raises serious concerns about the effects of the substance on neurodevelopment, which may increase vulnerability in these children to later mental disorders and substance misuse. Pregnant women are advised against alcohol use, drug use and cigarette smoking during pregnancy. This study highlights the importance of more specific advice on the detrimental effects of cannabis on children.