Major depressive disorder

Major depression, also known as unipolar or major depressive disorder (MDD), is distinguished by persistent feelings of sadness and a disinterest in external stimuli. "Unipolar" signifies a contrast with bipolar depression, where individuals experience swings between depression and mania.

Unipolar depression involves one or more episodes of severe and prolonged depression, marked by persistent sadness, suicidal thoughts, loss of pleasure, concentration difficulties, appetite and sleep changes. It is not caused by medical issues, drugs, or psychosis. If manic or hypomanic episodes occur, it becomes Bipolar Disorder.

Unipolar depression is a global health concern with varying prevalence worldwide. Rates range from 3% in Japan to 17% in the US, with most countries falling within an 8–12% range. Major Depressive Disorder (MDD) affects 121 million people worldwide and is a leading cause of disability, affecting more women than men and contributing substantially to the global burden of disease. It is the second leading cause of disability-adjusted life years. MDD also increases the risk of other medical conditions, including diabetes, heart disease, and stroke. Tragically, MDD can lead to suicide, with a substantial proportion of suicides occurring during a depressive episode. Patients with MDD are at a significantly higher risk of suicide...