We examined the impact of features of MDD episodes on single depressive symptoms.

Initial age of onset, episode number, & onset age of each episode were examined.

Most symptoms were not associated with course features.

Findings for fatigue and suicidal ideation were robust to multiple comparison correction.

Major depression is characterized by an episodic course with symptom manifestations differing across episodes. Previous work has found that symptom presentation differs across age. However, studies of symptom presentation have largely focused on symptoms in individual episodes, requiring further investigation of longitudinal symptom change. This study explored the impact of the initial age of onset, the number of episodes, and age of onset of each episode on individual depressive symptoms, while accounting for episode severity. We used data from the Oregon Adolescent Depression Project (N = 629) examining participants with at least one major depressive episode, assessed by diagnostic interview, across a 15-year follow-up. Multilevel logistic regression models revealed that approximately 20–25% of the main effects were significant and some were qualified by cross-level interactions. However, only a few associations remained robust after correcting for multiple comparisons. Specifically, older initial age of onset was associated with fatigue, younger initial age of onset for the first episode was associated with suicidal ideation, and a lower episode number was associated with weight loss. These findings highlight potential initial age of onset and scar effects influencing symptom manifestation, but require replication.

Major depressive episode

Symptom presentation

Recurrence

Age of onset

Phenomenology

Adolescence

© 2024 The Authors. Published by Elsevier Ltd.