What is a psychological disorder, you might ask. A psychological disorder is a set of behavioral or psychological symptoms that affect several areas of life and/or create distress in the person experiencing these symptoms. There are approximately 250 different psychological disorders, most of which fall into a category of similar or related disorders. Some of the most important diagnostic categories include eating disorders, mood disorders, somatoform disorders, sleep disorders, anxiety disorders, and personality disorders. Recent research has revealed that psychological disorders are far more widespread than previously thought. According to the National Institute of Mental Health, approximately 26% of U.S. adults over the age of 18 experience some type of diagnosable mental disorder in a given year. The 1994 National Comorbidity Survey reported that 30 percent of respondents had experienced symptoms of at least one psychological disorder in the previous year. The survey also indicated that almost half of all adults suffer from some form of mental disorder at some point in their lives. Mood disorders are one of the most common psychological disorders in America. Mood disorders are estimated to affect more than 20 million Americans. There are many forms of mood disorders, including dysthymic disorder. This mood disorder is a less serious form of depression. Although less extreme, dysthymic disorder causes long-lasting mood swings. With dysthymic disorder, a low, gloomy mood takes over your life almost every day for two years or more. Dysthymia contrasts with a full-blown major depressive episode that lasts two years or more, called chronic major depression. Dysthymic disorder can occur alone or in association with other psychiatric or mood disorders...... middle of article...... personality disorders are thought to be caused by a combination of these genetic and environmental influences. You may have a genetic vulnerability to developing a personality disorder and your life situation may trigger the actual development of a personality disorder. Personality disorders often begin in childhood and last into adulthood. There is, however, a reluctance to diagnose personality disorders in a child because the patterns of behavior and thinking might simply reflect the adolescent's experimentation or temporary developmental phases. Complications and problems that personality disorders can cause, Depression, Anxiety, Eating disorders, Suicidal behavior, Self-harm, Reckless behavior, Risky sexual behavior, Child abuse, Alcohol or substance abuse, Assault or violence , Incarceration, Relationship difficulties, Social isolation, and academic and professional problems.