Major depression (or “major depressive disorder,” as stated in the “Statistical Diagnostic Manual of Mental Disorders – DSM 5”), is a mood disorder that is characterized by the presence of deep and persistent sadness, apathy and disinterest in all aspects of life, lack of energy and hope for the future, and inability to make plans and take pleasure in habitual activities.
The state of psycho-emotional prostration typical of major depression arises and is maintained independently of unfavorable external circumstances and is usually accompanied by physical symptoms such as alterations in appetite and sleep-wake rhythm, headaches, gastrointestinal complaints, generalized fatigue, and muscle and joint soreness, varying in combination and intensity from case to case.
Although it can occur at any time of life, major depressive disorder is most frequently diagnosed between the ages of 25 and 45 and at older ages; women are affected more than men, especially after menopause.
After onset, the disease is maintained chronically throughout life, with an unpredictable and subjective alternation of episodes of acute depression and periods of psycho-emotional well-being, both of variable duration.