Evidence for the need of long-term treatment of major depression

Depression is a chronic and recurring illness. Yet, treatment recommendations historically have not prioritized recurrence prevention. Studies addressing the benefit of depression maintenance treatment began appearing approximately 35 years ago. Most studies were limited in number of participants, relatively short observation periods (few studies reach >2 years), minimal monitoring of adherence, and polypharmacy. There is a paucity of head-to-head studies that compare medication, combination studies of psychotherapy and medications, or studies of neuromodulation modalities. Despite methodological shortcomings, there is consistent and robust evidence that maintenance therapy for recurrent depression at least halves the recurrence of depressive episodes over a 2-year follow-up period and potentially longer. Modest but growing evidence indicates that specific psychotherapies may prevent recurrences for mild-to-moderate depression and that combination treatment of antidepressants and psychotherapy may provide optimal results. Data remain inconclusive for newer neuromodulation treatments. Factors that support the need for maintenance treatment include a history of previous episodes, early onset, positive family history, high severity of the previous episodes, and possibly a history of prompt recurrence following previous discontinuation.