Depressive Disorders

Definition

Depressive disorders involve persistent feelings of sadness and worthlessness and a lack of desire to engage in formerly pleasurable activities.

Related terms

Major Depressive Disorder (MDD):

A mood disorder characterized by severe symptoms that interfere with one's ability to work, sleep, study eat and enjoy life.

Dysthymia (Persistent Depressive Disorder): A chronic form depression where individuals have less severe but long-term depressive symptoms that last for at least two years.

Seasonal Affective Disorder (SAD):

This is depression associated with late autumn and winter and thought to be caused by a lack of light.