New parents and mental disorders: a population-based register study.

CONTEXT: Studies on postpartum mental disorders among mothers have primarily focused on either depression or psychoses and have generally not included the broader spectrum of mental disorders. A few studies have found that some men have symptoms of depression after becoming fathers, but these studies have not documented whether this exceeds the morbidity among men in general.
OBJECTIVES: To estimate the risk of postpartum mental disorders necessitating hospital admission or outpatient contact for mothers as well as fathers during a 1-year postnatal follow-up period after birth of first live-born child and to investigate whether parents in general differ from nonparents in the risk of admission with a mental disorder and how this difference varies with age. DESIGN, SETTING, AND PATIENTS: Register-based cohort formed by linking information from Danish health and civil service registers. A total of 2,357,942 Danish-born persons were followed up from their 15th birthday or January 1, 1973, whichever came later, until date of onset of the disorder in question, date of death, date of emigration from Denmark, or July 1, 2005, whichever came first. From 1973 to 2005, a total of 630,373 women and 547,431 men became parents for the first time, and during the first year after childbirth, these parents contributed 1,115,639 person-years at risk. MAIN OUTCOME MEASURE: First-time psychiatric hospital admission or outpatient contact 0 to 12 months after becoming a parent.
RESULTS: A total of 1171 mothers and 658 fathers were admitted with a mental disorder to a psychiatric hospital during the first 12 months after parenthood, and the corresponding prevalence of severe mental disorders through the first 3 months after childbirth was 1.03 per 1000 births for mothers and 0.37 per 1000 births for fathers. Compared with women who had given birth 11 to 12 months prior, primiparous women had an increased risk of incident hospital admission with any mental disorder through the first 3 months after childbirth, with the highest risk 10 to 19 days postpartum (relative risk [RR], 7.31; 95% confidence interval [CI], 5.44-9.81). Among mothers, risk was also increased for psychiatric outpatient contacts through the first 3 months after childbirth, also with the highest risk occurring 10 to 19 days postpartum (RR, 2.67; 95% CI, 1.99-3.59). Unlike motherhood, fatherhood was not associated with any increased risk of hospital admission or outpatient contact.
CONCLUSION: In Denmark, the risk of postpartum mental disorders among primiparous mothers is increased for several months after childbirth, but among fathers there is no excess of severe mental disorders necessitating admission or outpatient contacts.