All the results were adjusted for paternal psychopathology, paternal immigrant status, maternal psychopathology, maternal depression, maternal substance abuse, number of previous births, maternal marital status, maternal socio-economic status, maternal smoking during pregnancy, and the infant's birthplace.

Childhood depression can be addressed preventively

Depression is a common psychiatric disorder that has been reported to affect 1-2 percent of preschool and prepubertal children and 3-8 percent of adolescents. However, childhood depression is a severe disorder and its prevention can be advanced with the identification of at-risk groups.

"The study highlights the need for preventive interventions for high-risk infants and support programmes for parental mental health during pregnancy and neonatal care, especially for extremely preterm infants and growth-retarded full-term infants. Follow-up care practices should include psychosocial screening and developmental testing for children born preterm and their families, with appropriate support for sound mental health," says researcher Subina Upadhyaya from the Research Centre for Child Psychiatry, University of Turku.

"Future studies should examine the risk associated with preterm birth and infant long-term outcomes in the present era of family centered neonatal care practices," she continues.

The study included 37,682 children born in Finland between January 1987 and December 2007 and diagnosed with depression. They were compared with 148,795 matched controls without depression.

The study is part of a larger body of research that investigates the associations between antenatal risk factors and major psychiatric disorders.

"The results are significant both for understanding the risk factors for psychiatric disorders and for prevention, notes the primary investigator," Professor Andre Sourander.

The study belongs to the INVEST Research Flagship funded by the Academy of Finland Flagship Programme. INVEST aims at providing a new model for the welfare states that is more equal, better targeted to at risk groups, more anticipatory as well as economically and socially sustainable.