Depression

For a lay person:

Depression is a common mental health condition that causes a persistent low mood or loss of interest in things you used to enjoy, lasting for weeks or longer. It can affect sleep, appetite, energy, concentration and self-esteem, and sometimes leads to thoughts of self-harm or suicide. It can affect anyone, is not a sign of weakness and is treatable.

For a trained medical person:

Major depressive disorder involves at least two weeks of depressed mood or anhedonia with associated somatic and cognitive symptoms causing functional impairment, arising from interacting genetic, neurobiological, psychological and social factors. Diagnosis is clinical against DSM-5 or ICD-11 criteria, using tools such as the PHQ-9, with assessment of suicide risk and screening for bipolar disorder and medical causes such as hypothyroidism. First-line treatment is psychological therapy (such as CBT) and/or antidepressants, with stepped care and specialist referral for severe, psychotic or treatment-resistant illness.

In Chinese medicine:

Liu and Tseng's textbook differentiates this condition into these patterns: Knotted Phlegm and Qi Stagnation; Qi Deficiency and Phlegm Accumulation; Heart and Spleen Deficiency. Treatment follows the pattern a patient presents with, not the Western diagnosis alone.

When to get help: If you are thinking about suicide or self-harm, call your local emergency number or a crisis line now, or go to an emergency department. Depression needs medical or psychological treatment and Chinese medicine is adjunctive at most; do not stop prescribed antidepressants without your doctor's advice, and check before using herbs such as St John's wort, which interacts dangerously with many antidepressants and other medicines.