Even at their highest intensity, symptoms of mood disorders are often misinterpreted as merely mood swings. Worse, they are sometimes considered personality flaws rather than real medical conditions. The truth is that mood disorders are treatable medical illnesses caused by a complex interaction of genetic, biochemical and environmental factors. There are several types of mood disorders: major depressive disorder (unipolar depression); dysthymia; bipolar disorder (also known as manic depression); cyclothymia. This includes the following: Bipolar disorder Depression Mania