Risk of recurrence after a single manic or mixed episode - a systematic review and meta-analysis

For the first time to estimate the risk of recurrence among patients with a single manic/mixed episode by systematically reviewing prior studies on cohorts of adults, and cohorts of children and adolescents, respectively.

A systematic literature search up to August 2017 was carried out including studies in which < 25% of the participants were estimated to have had a mood episode that required pharmacological treatment prior to the index manic or mixed episode at inclusion.

Three studies including a total of 293 adult patients with a single manic or mixed episode and three studies of children and adolescents including 126 patients were identified. In the adult studies, 31%, 40% and 42% experienced recurrence after recovery within 1 year, 59% after 2 years, and 58% after 4 years, respectively. In the studies on children and adolescents, 40% and 52% experienced recurrence after recovery within 1 year, 30% and 60% after 2 years and 64% and 67% after 4 to 5 years, respectively. Results from meta-analyses showed a 1-year rate of recurrence of 35% (95% confidence interval [CI]: 30-41%) in adults, and in adolescents/children, a 1-year rate of recurrence of 48% (95% CI: 38-58%), a 2-year rate of 46% (95% CI: 33-60%) and a 4-5-year rate of recurrence of 65% (95% CI: 52-77%; as data from different studies were included at 1, 2 and 5 years, rates of recurrence did not increase steadily with time).

The rate of recurrence is high among adults as well as children and adolescents. It is important that clinicians and patients as well as relatives are well informed about these high risks when deciding to start maintenance treatment or not following onset of a single manic or mixed episode.