Depressive disorders

Examiners love depressive disorders because the numbers are precise and the look-alikes are sneaky. Miss one duration cutoff and a major depressive episode turns into persistent depressive disorder — same sad client, different diagnosis.

Major depressive disorder (MDD) requires five or more symptoms during the same two-week period, and at least one symptom must be either depressed mood or loss of interest/pleasure (anhedonia). Remember the rest with SIG E CAPS: Sleep change, Interest loss, Guilt/worthlessness, Energy loss, Concentration problems, Appetite/weight change, Psychomotor agitation or retardation, Suicidality. Symptoms cause distress or impairment and are not due to a substance or medical condition.

Persistent depressive disorder (PDD, dysthymia) is the low-grade marathon: depressed mood most of the day, more days than not, for at least 2 years (1 year in children/adolescents). The catch — during those two years the person is never without symptoms for more than 2 months at a time. PDD trades intensity for chronicity; MDD trades chronicity for intensity, and the two can co-occur (double depression).

The bereavement distinction is the classic trap. Grief and depression can overlap, but grief typically comes in waves tied to reminders of the loss, preserves self-esteem, and keeps positive emotions accessible; the predominant affect is emptiness and loss. MDD brings persistent low mood, worthlessness and self-loathing, and pervasive anhedonia. DSM-5-TR removed the old bereavement exclusion, so a grieving person who meets full criteria can be diagnosed with MDD — clinical judgment decides.

Clinical Pearl: Lock the numbers: MDD is 5+ symptoms for 2 weeks (one must be depressed mood or anhedonia); PDD is 2 years of depressed mood (1 year in youth). Grief centers on emptiness and loss and preserves self-worth; depression centers on worthlessness and pervasive anhedonia.