Hospital-Treated Psychiatric Disorders in Adults with a Single-Parent and Two-Parent Family Background: A 28-Year Follow-up of the 1966 Northern Finland Birth Cohort

This study investigates the relationship between the family type (two-parent and 4 different single-parent types, mainly divorced) during childhood up to 14 years of age and adult hospital-treated psychiatric disorders in a sample from the unselected, general population Northern Finland 1966 Birth Cohort (N = 11,017). Up to the end of 1994, a total of 387 individuals (3.5%) had a hospital-treated psychiatric disorder, with 3.1% in two-parent families and 5.4% in single-parent families (p < .001). The single-parent family was not associated with the child's schizophrenia or other psychotic disorders. The adjusted odds ratios (OR) for personality disorders were highest among individuals without a father before the age of 14 years (OR 4.8), or at birth only (OR 4.0), or with a history of parental divorce (OR 2.8). Parental divorce was also associated with alcoholism (OR 3.7) and parental death with depressive disorders (OR 3.4). In conclusion, we found an elevated risk of hospital-treated nonpsychotic disorder among individuals from a single-parent family background. It is likely that a combination of the single-parent family and psychosocial and/or genetic risk may influence the development of these disorders.     

Early life origins of psychological development and mental health

According to the Developmental Origins of Health and Disease (DOHaD)‐hypothesis, conditions early in life may have life‐long consequences. In a series of epidemiological birth cohort and clinical studies and natural experiments, we have had the chance to test the extent to which this hypothesis is useful in understanding individual differences in psychological development and mental health. Our findings have provided evidence that individual differences in cognitive, social and emotional development and in mental health may lie in early life circumstances, and add significantly to the literature by pointing out which periods of early growth are the most critical. These findings are also important in translating pre‐clinical evidence to humans. What remains less clear, however, is what the mechanisms of programming are. Thus, further research is needed to elucidate these mechanisms before information on the early life origins of health and disease can be used in designing prevention and intervention programs.