Loss of interest in sex or less sexually active than usual. Withdrawal from others. Physical symptoms such as headaches, digestive problems, aches and pains. At highest risk are individuals who have already experienced an episode of major depression, have close relatives with severe depression, or who abuse alcohol or drugs. Depression may strike any age group, from young children to seniors, with an average onset in the mid-twenties.
Women are two to three times more likely to develop depression than men.
Some individuals may be able to point at various life events and be certain they are the reasons for their depression. For others depression comes out of the blue, with no apparent reason. Depression is an illness characterized by neurochemical abnormalities that can cause significant disability. The cause may be one or a combination of biological, genetic, chemical, psychological, social, developmental, and environmental factors. Heredity, brain chemistry, hormonal systems, and sleep-wake controls are included in biological factors.