Types of depression: Mental health professionals often use the term clinical depression to refer to any of the below forms of depression.  There are several different forms of depression, including:  Bipolar affective disorder Bipolar affective disorder is characterized by two or more episodes of disturbed mood and activity levels of opposite extremes (i.e., the patient experiences both elevated mood and energy levels – hypomania or mania – and decreased mood and energy levels – depression). Cyclothymia Characterized by a persistent instability of mood whereby the patient experiences both depression and mild elation however the severity or duration is not sufficient for a diagnosis of bipolar affective disorder.  Cyclothymia is often diagnosed in relatives or patients with bipolar affective disorder.  Depressive Episode This can range from mild, moderate or severe depressive episodes.  Symptoms include decreased mood and reduction of energy and activity levels.  Patients usually feel tired after only minimal activity and loss of concentration and appetite is common.  Reductions are common in self-esteem and confidence, and it is common for patients to experience feelings of guilt or self-worthlessness.  Dysthymia Depressed mood lasting numerous years however the severity is not to the extent of a recurrent depressive disorder diagnosis. Hypomania This refers to persistent elevations in mood, energy and activity, and is usually characterized by feelings of well-being and both mental and physical efficiency.  Other symptoms include increased sociability, talkativeness, familiarity and a decrease in the need for sleep; however these symptoms do not usually cause workplace disruption or lead to social rejection.  Manic episode This diagnosis is used for single episodes. Mania without psychotic symptoms This is characterized by elevated mood that may vary from carefree joviality to complete excitement.  Such elation is often accompanied by an increase in energy levels, rate of speech, hyperactivity, distractibility and decreased need for sleep.  Self-esteem is often enhanced during such episodes and patients may experience a loss of appropriate social inhibitions that may lead to reckless or inappropriate behavioral patterns that are uncharacteristic of the individual. Mania with psychotic symptoms In addition to symptoms described above, delusions or hallucinations are present or the patient experiences such an increase in motor activity or excitement that they are often incomprehensible.  Persistent mood (affective) disorders This diagnosis is given to those who suffer from persistent mood disorders in which the severity of episodes is not sufficient to meet diagnostic criteria for hypomanic or depressive episodes.  These disorders may endure for many years, the distress and disability may be considerable. Recurrent depressive disorder Repeated episodes of depression without mood elevations, with the exception of immediately after a depressive episode.