Hypomania spectrum disorder in adolescence: a 15-year follow-up of non-mood morbidity in adulthood.

Background: We investigated whether adolescents with hypomania spectrum episodes have an excess risk of mental and physical morbidity in adulthood, as compared with adolescents exclusively reporting major depressive disorder (MDD) and controls without a history of adolescent mood disorders.

Methods: A community sample of adolescents (N = 2 300) in the town of Uppsala, Sweden, was screened for depressive symptoms. Both participants with positive screening and matched controls (in total 631) were diagnostically interviewed. Ninety participants reported hypomania spectrum episodes (40 full-syndromal, 18 with brief episode, and 32 subsyndromal), while another 197 fulfilled the criteria for MDD without a history of a hypomania spectrum episode. A follow up after 15 years included a blinded diagnostic interview, a self-assessment of personality disorders, and national register data on prescription drugs and health services use. The participation rate at the follow-up interview was 71% (64/90) for the hypomania spectrum group, and 65.9% (130/197) for the MDD group. Multiple imputation was used to handle missing data.

Results: The outcomes of the hypomania spectrum group and the MDD group were similar regarding subsequent non-mood Axis I disorders in adulthood (present in 53 vs. 57%). A personality disorder was reported by 29% of the hypomania spectrum group and by 20% of the MDD group, but a statistically significant difference was reached only for obsessive-compulsive personality disorder (24 vs. 14%). In both groups, the risk of Axis I disorders and personality disorders in adulthood correlated with continuation of mood disorder. Prescription drugs and health service use in adulthood was similar in the two groups. Compared with adolescents without mood disorders, both groups had a higher subsequent risk of psychiatric morbidity, used more mental health care, and received more psychotropic drugs.

Conclusions: Although adolescents with hypomania spectrum episodes and adolescents with MDD do not differ substantially in health outcomes, both groups are at increased risk for subsequent mental health problems. Thus, it is important to identify and treat children and adolescents with mood disorders, and carefully follow the continuing course.