Mood Disorders: The Signs, Symptoms, Causes, and Treatment

Also called clinical depression, major depressive disorder (MDD) involves long-lasting depression that impairs your ability to function. The Depression and Bipolar Support Alliance reports that major depressive disorder impacts around 17.3 million American adults annually, equivalent to 7.1% of the U.S. population over 18 years old.

A major depressive episode may occur just once in your life. But it's common for major depression to come back multiple times if left untreated. Episodes often begin following a major life stressor but then persist long after the event is over.

Depression is a broad term that can describe many types of depression disorders, from major depression to seasonal affective disorder and more. In general, depression refers to significant and persistent feelings of sadness and hopelessness that negatively impact mood and behavior.

Bipolar disorder causes extreme shifts in mood and energy levels, resulting in alternating episodes of mania and depression. The American Psychiatric Association (APA) estimates that bipolar disorder affects around 7 million Americans every year, which is approximately 3% of the total adult population in the United States. Bipolar symptoms can be divided into manic and depressive episodes.

Manic and depressive episodes can last weeks or months. The cycles of bipolar disorder are often unpredictable and uncontrollable without proper treatment. According to Mental Health America (MHA), bipolar disorder affects both men and women equally, with similar rates of occurrence across genders.

Also called dysthymia, persistent depressive disorder causes depression that lasts for at least two years. It involves ongoing feelings of sadness, hopelessness, and low self-esteem. Symptoms are less severe than with major depression but persist for a long time and can seriously lower quality of life. People with this condition may struggle to remember what feeling happy and content is like.

Also called SAD, seasonal affective disorder is a type of depression triggered by changing seasons. Most commonly, people experience depressive symptoms during the winter months when there is less natural sunlight.

Symptoms typically resolve in spring and summer months when there is more sunlight. Light therapy, involving regular exposure to artificial light, can help treat SAD. Antidepressants may also be prescribed.

A severe form of premenstrual syndrome, premenstrual dysphoric disorder causes extreme mood shifts and physical symptoms a week or two before your period. According to the National Center for Biotechnology Information (NCBI), between 3-8% of women of reproductive age are estimated to have Premenstrual Dysphoric Disorder.

Symptoms improve after your period starts and must reoccur monthly to be considered PMDD. Oral contraceptives and antidepressants can help manage symptoms. Lifestyle changes like stress management, exercise, and dietary adjustments may also help.

Disruptive mood dysregulation disorder involves severe, ongoing irritability along with frequent temper outbursts beyond what is typical for a child's age.

Symptoms must begin before age 10, be present for at least a year, and not be due to a developmental disorder like autism. Parents often mistake this disorder for bipolar, but treatments differ.