Unipolar depressive disorder and bipolar disorder are common mental diseases that impose a very high societal burden in terms of morbidity, mortality, lost productivity, and costs. The 1-year prevalence of bipolar disorder is 1–2%, while the 1-year prevalence of depressive disorder is 3–6%. Mean age at onset is in the early to mid twenties for bipolar disorder and around 30 years of age for depressive disorder. The risk of recurrence of episodes after a first depression or manic episode is high, especially for bipolar disorder, and approximately 1% of patients convert from depressive disorder to bipolar disorder per year. Comorbidity with anxiety disorders, alcohol and drug dependence, and personality disorders is high. Both disorders are associated with long-term deficits in social, functional, and cognitive outcomes, and life expectancy is decreased by approximately 10 years, emphasizing the need for future studies on early intervention.
Early Intervention in Bipolar Disorder: Impact on Clinical Course and Cognitive Outcomes