The clinical course of major depressive disorder after the initial depressive episode varies from patient to patient, and whilst roughly half of patients will not go on to experience further recurrence, a minority of patients will experience unremitting depression.1,2

References:
1.Eaton WW, Shao H, Nestadt G, et al. Population-based study of first onset and chronicity in major depressive disorder. Arch Gen Psychiatry 2008; 65 (5): 513–520.

2.Herrman H, Patel V, Kieling C, et al. Time for united action on depression: a Lancet-World Psychiatric Association Commission. Lancet 2022; 399 (10328): 957–1022.