Major Depressive Disorder (MDD) is a prevalent psychiatric condition affecting over 300 million people globally, with females more commonly affected than males. Diagnosis involves meeting DSM-5 criteria, including symptoms like depressed mood, loss of interest, weight changes, sleep disturbances, and suicidal ideation.

The chapter outlines the criteria for diagnosing Major Depressive Disorder (MDD), including symptoms like persistent feelings of fatigue, worthlessness, concentration issues, and suicidal thoughts. It explains the A, B, C, D, and E criteria for MDD diagnosis, along with exclusion criteria and specifiers for different types of depressive episodes.

Learn how to simplify the diagnosis process using the mnemonic device M Ziggy Caps MCT, which requires at least five symptoms including low mood and interest loss from the DSM-5 criteria. The mnemonic helps identify symptoms like sleep disturbances, guilt, low energy, concentration difficulties, appetite changes, and more.

The chapter discusses various biological and psychosocial explanations for Major Depressive Disorder (MDD). Biological causes include genetic factors, neurotransmitter depletion, HPA axis activation, immunological dysfunction, neuroanatomical changes, and neurophysiological changes. Psychosocial factors involve cognitive theories like Beck's triad, psychodynamic theories, environmental stressors, and associations with other psychiatric disorders.

Exploration of risk factors for major depressive disorder includes female gender, family history, past experiences, stressors, and personality traits. Treatment options encompass lifestyle modifications, biological treatments like SSRIs and SNRIs, ECT for severe cases, and phototherapy for specific MDD cases.