The cause (etiology) of<unk>  is unknown, but recent findings may suggest a link between<unk>  and bipolar disorders, pointing to the importance of genetic factors. A small subgroup of patients with<unk>  has temporal lobe epilepsy.
Recurrent brief depression
Long-term depression
Treatment-resistant depression
Psychological effects of Internet use
Double depression
Associated features of bipolar disorder
Outline of bipolar disorder
Depression in childhood and adolescence