Preventive therapy reduces depression

The study in 300 adolescents with a history of depression compared regular cognitive behavioural prevention (CBP) sessions with usual care.

Only 37% of adolescents in the CBP group had depression onset compared with 48% in the usual care group, giving a number needed to treat of 10.

However, when parental depression at baseline was factored in, there was no difference between the two groups, with a number needed to treat of 54.

JAMA Psychiatry 2013; online 4 Sept