Persistent depressive disorder

Persistent depressive disorder is the case where the client says "I've always been this way," and the exam tests whether you recognize chronicity rather than a single episode.

Criteria at exam depth. Depressed mood for most of the day, more days than not, for at least two years in adults (one year in children and adolescents, where mood can be irritable). While depressed, the client has two or more of six symptoms: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, and hopelessness. During the two-year period the client has never been without symptoms for more than two months at a time. There has never been a manic or hypomanic episode, and criteria for cyclothymic disorder have never been met. Symptoms are not better explained by a psychotic disorder, substance or medical condition, and they cause distress or impairment. Major depressive episodes may be present continuously across the two years; when full episode criteria are met, DSM-5-TR has both diagnosed: MDD plus PDD with the matching specifier (e.g., with intermittent major depressive episodes, with current episode). Specifiers: early onset (before age 21) or late onset (21 or older); with pure dysthymic syndrome, with persistent major depressive episode, or with intermittent major depressive episodes (with or without a current episode); plus severity and features such as anxious distress or atypical features.

Hinge differentials.

• Major depressive disorder, recurrent: clear episodes with full recovery between them (symptom-free stretches longer than two months) point to recurrent MDD, not PDD.
• Personality disorders: low self-worth may look characterological; PDD is defined by the mood syndrome and duration and can co-occur.
• Cyclothymic disorder: includes periods of hypomanic symptoms; PDD never does.
• Substance or medical causes: chronic alcohol use, hypothyroidism and medications can produce long-standing low mood.
• Adjustment disorder: tied to a stressor and does not run two years of daily low mood.

On the NCMHCE. Clients often present for something else (relationship strain, work stagnation) and minimize mood because it feels like personality. The counselor should take a longitudinal history (when did you last feel well for two months?), screen for suicide risk (chronic hopelessness raises risk, especially with a superimposed major episode), and recommend a medical evaluation. Treatment typically combines psychotherapy, such as CBT or CBASP (developed specifically for chronic depression), with referral for antidepressant evaluation, since chronic depression often responds better to combined care. Set realistic goals: improvement is gradual, and hopelessness about change is itself a target.

Clinical Pearl: Two years (one in youth), two of six symptoms, never symptom-free more than two months. Symptom-free stretches longer than two months between discrete episodes point to recurrent MDD instead.