Objectives Besides medical needs, psychotropic medication use in adolescence might be conditioned by the cultural context of the family. This knowledge is relevant for both detecting inequities in healthcare, and identifying information bias in epidemiological studies using psychotropic medication as a proxy for impaired psychological health. Therefore, we investigated whether, independent of needs, the socioeconomic characteristics of the mother's country of birth are associated with psychotropic medication use in Swedish-born adolescents.

Design Prospective cohort study.

Setting The Swedish population.

Participants By linking the Swedish Medical Birth Registry to other national registers, we identified all 324 510 singletons born between 1988 and 1990 and who were alive and residing in Sweden until the age of 18 years (2006−2008).

Primary and secondary outcome measures The primary outcome was participants’ use of psychotropic medication in the year they turned 18. In the analyses, applying a life-course approach, we included both the mother's and the children's characteristics throughout pregnancy, delivery, infancy, childhood and adolescence when calculating a risk score (RS) to adjust for needs. We classified the mother's country of birth according to the gross national income (GNI) per capita of each country.

Results Overall, the lower the income of the mother's birth country, the lower the probability of psychotropic medication use among children. When adjusting for needs, the association became even stronger.

Conclusions Besides medical needs, use of psychotropic medication by descendants of immigrants seems conditioned by the socioeconomic characteristics of the mothers’ countries of birth. The threat of information bias must be considered if psychotropic medication is used a proxy for impaired psychological health in descendants of immigrants.