An estimated 15 percent of people hospitalized for depression eventually take their own lives. Others have ongoing, chronic symptoms. Depression Can Involve Mood Cycles. In some cases, symptoms appear suddenly for no apparent reason. In others, the symptoms seem to be associated with a life crisis, stress, or other illness.
Research shows that depressive illnesses run in families.
When four or more of these symptoms last longer than 2 weeks or interfere with ordinary functioning, professional treatment is needed. Research Has Improved Treatments. There are effective medications and psychological treatments that often are used in combination. A number of short-term talk therapies to treat clinical depression have been developed in recent years. Several types of medications are available.