Depression in adults

Depression can describe both a mood and an illness.

Major depressive disorder is a clinical syndrome involving mood, neurovegetative functions, cognition, and behaviour.

Lifetime prevalence of approximately 10%.

Risk factors include prior depression and a family history of depression. Recent bereavement, stress, or medical illness may contribute.

For screening and diagnosis, self-rating forms are helpful, but clinical diagnosis is essential. Positive screening should trigger full history, mental status examination, treatment, and follow-up.

Most patients respond well to treatment with medication, talk therapy, or a combination of both.

Suicidal ideation can occur before and peak during treatment, so early and careful follow-up is advised.

Depressive disorders are typically characterised by persistent low mood, loss of interest and enjoyment, neurovegetative disturbance, and reduced energy, causing varying levels of social and occupational dysfunction. Depressive symptoms include depressed mood, anhedonia, weight changes, libido changes, sleep disturbance, psychomotor problems, low energy, excessive guilt, poor concentration, and suicidal ideation. In some cases the mood is not sad, but anxious or irritable or flat.[1]American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.

There is no subthreshold (minor) depression diagnosis in Diagnostic and statistical manual of mental disorders, fifth edition, text revision (DSM-5-TR), but the label has sometimes been applied to diagnose a patient with two to four depressive symptoms, including depressed mood or anhedonia, lasting longer than 2 weeks.

Persistent depressive disorder is characterised by at least 2 years of a depressed mood for most of the day, for more days than not, for at least 2 years.[1]American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.