Major Depressive Disorder (MDD)

Definition

A mental health disorder characterized by persistent feelings of sadness, loss of interest in activities, and difficulty carrying out daily tasks for at least two weeks.

Related terms

Persistent Depressive Disorder (Dysthymia): A chronic form of depression where a person experiences depressive symptoms for at least two years.

Seasonal Affective Disorder (SAD):

A type of depression that's related to changes in seasons — SAD begins and ends at about the same times every year.

Postpartum Depression: A serious mood disorder experienced by women after giving birth that includes severe depressive symptoms such as extreme sadness, fatigue, loneliness, hopelessness, suicidal thoughts, fears about hurting the baby, and feelings of disconnect from the child.