Three main types of depressive disorders—major depression, persistent depressive disorder,
and bipolar disorder—can occur with any of the anxiety disorders.
Major depression
Major depression involves at least five of these symptoms for a two-week period. Such
an episode is disabling and will interfere with the ability to work, study, eat, and
sleep. Major depressive episodes may occur once or twice in a lifetime, or they may
recur frequently. They may also take place spontaneously, during or after the death
of a loved one, a romantic breakup, a medical illness, or other life event. Some people
with major depression may feel that life is not worth living and some will attempt
to end their lives.
Persistent Depressive Disorder
Persistent depressive disorder, or PDD, (formerly called dysthymia) is a form of depression
that usually continues for at least two years. Although it is less severe than major
depression, it involves the same symptoms as major depression, mainly low energy,
poor appetite or overeating, and insomnia or oversleeping. It can manifest as stress,
irritability, and mild anhedonia, which is the inability to derive pleasure from most
activities.
Bipolar Disorder
Bipolar disorder, once called manic-depression, is characterized by a mood cycle that
shifts from severe highs (mania) or mild highs (hypomania) to severe lows (depression).
During the manic phase, a person may experience abnormal or excessive elation, irritability,
a decreased need for sleep, grandiose notions, increased talking, racing thoughts,
increased sexual desire, markedly increased energy, poor judgment, and inappropriate
social behavior. During the depressive phase, a person experiences the same symptoms
as would they would during major depression. Mood swings from manic to depressive
are often gradual, although occasionally they can occur abruptly.
Depression and Anxiety Disorders: Not the Same!
Depression and anxiety disorders are different, but people with depression often experience
symptoms similar to those of an anxiety disorder, such as nervousness, irritability,
and problems sleeping and concentrating, but each disorder has its own causes and
its own emotional and behavioral symptoms. Many people who develop depression have
a history of an anxiety disorder earlier in life. There is no evidence one disorder
causes the other, but there is clear evidence that many people suffer from both disorders.
Learn more about Depression from the National Institutes of Health