Depression
What is depression?
Clinical depression (major depressive episode, MDD in DSM-5) is a mood disorder lasting at least 2 weeks, with at least 5 of 9 symptoms: depressed mood, loss of interest, appetite/sleep changes, energy loss, worthlessness, concentration problems, thoughts of death. Crucially β depression β "a sad day". Sadness passes; depression pervades all life domains and changes how you think about yourself.
Scale
The WHO estimates ~280 million people worldwide have depression. It is the leading cause of disability globally. Women affected 2Γ as often as men (but men more often go untreated).
How is it measured?
PHQ-9 (Patient Health Questionnaire) β the most widely used screening tool, 9 items, 5 severity bands. BDI-II (Beck Depression Inventory) β 21 items, a classic. HAM-D (Hamilton Rating Scale for Depression) β clinical interview.
What next?
A score above threshold β always consult a specialist (psychologist, psychiatrist, GP). Treatment: psychotherapy (CBT, IPT), pharmacotherapy (SSRIs, SNRIs) or a combination. It is treatable. β οΈ If you have thoughts of self-harm β call a crisis line (UK/EU: 116 123; US: 988; international: findahelpline.com).