Affective dynamics in adolescents with major depressive disorder and subthreshold depression: an experience sampling...

Sub-threshold depression (SD) affects around 11% of adolescents and can be as impairing as conditions reaching the full diagnostic criteria of Major Depressive Disorder (MDD). However, limited research has been conducted on how affective disturbances manifest in SD during adolescence, a period of affective vulnerability. We compared three groups of adolescents along the spectrum of depression on their positive affective (PA) and negative affective (NA) levels and dynamics, including variability, inertia, and reactivity to event-related stress and pleasure in daily life.

One hundred and ninety eight adolescents (age 12-18), grouped by psychiatric diagnosis (MDD = 66; SD = 35; healthy controls, HC = 88), completed a 14-day experience sampling on their smartphone, clinical ratings, and questionnaires. They were recruited from multiple sources, including an epidemiologic study and specialist clinics.

The level of NA was the highest in MDD, followed by SD and HC; vice versa for PA. MDD and SD displayed greater NA variability than HC. NA inertia was greater in MDD than SD and HC. NA reactivity (to event-related pleasure and stress) and PA reactivity (to event-related pleasure) were greater in MDD and SD than HC. SD showed greater PA reactivity to event-related stress than MDD.

Adolescents with SD were as reactive and expansive in their NA experience as the MDD group, but they did not stay in that negative state for as long. The SD group was more reactive than HC to event-related pleasure and stress, suggesting heightened sensitivity. Clinical implications of emotional sensitivity and flexibility on early intervention for depression are discussed.