Short summary

We conducted a population-based cohort study where we will link data from the Danish military draft cognition test with other nationwide registers to examine the association between maternal (and paternal) mental disorders and offspring cognitive ability.

Rationale

Mental disorders are among the most common diseases during pregnancy, with up to 15-25% of women experiencing depression or anxiety during pregnancy (1, 2). The number has increased dramatically over the last 20 years. Emerging research suggests that mental health problems in pregnancy negatively affect the child's cognitive development due to the environment in utero - even to a larger extent than maternal mental health problems that arise after the child is born (3-6). The main challenge with such research is the need for long-term follow-up and separating causal influences from confounding factors. We will extent previous findings on mechanisms driving the association by addressing stressors and major negative life events during the children's upbringing. Thereby, we aim to examine how severe expression of maternal (and paternal) anxiety and depression in pregnancy is associated with cognitive ability at age 18 using Danish nationwide register data with available data during a life cause. This knowledge is crucial to understand why maternal mental health problems have a stronger impact on some children than others. Ultimately, the project's findings will enable an improved and targeted preventive effort to better and more timely identify and support vulnerable mothers and their children to reduce the consequences of mothers' mental health problems on the children and ultimately inequality in society.

Description of the cohort

We will include N~350,000 Danish adults aged 18 years in 2013-2021 who attended the Conscription Board Examinations which include an intelligence test of cognitive ability (11).

Data and biological material

We will link each young adults on individual-level register data to their parents. The outcome measure is cognitive ability assessed by the Danish military cognitive test. The primary exposure measures are maternal anxiety and maternal depression in pregnancy derived from psychiatric hospital diagnoses and redeemed psychotropic prescriptions from the registers. In negative control exposure models, We will use measures of anxiety and depression of the mothers before and after pregnancy and of the fathers during pregnancy to test the robustness of whether maternal mental health problems alter the fetal brain in pregnancy due to the environment in utero. We will test which stressors and major life events occurring during upbringing that contribute to the causal mechanisms driving the association between maternal anxiety/depression in pregnancy and cognitive ability.

Collaborating researchers and departments

e.Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospitals The Capital Region, Frederiksberg, Denmark

• Gunhild Tidemann Okholm
• Merete Osler