Although the most reproducible finding in the epidemiology of major depressive disorder has been a higher prevalence in females, there are no clear differences between genders in symptoms, course, treatment response, or functional consequences. In women, the risk for suicide attempts is higher, and the risk for suicide completion is lower. The disparity in suicide rate by gender is not as great among those with depressive disorders as it is in the population as a whole.
The possibility of suicidal behavior exists at all times during major depressive episodes.
The most consistently described risk factor is a past history of suicide attempts or threats, but it should be remembered that most completed suicides are not preceded by unsuccess- ful attempts. Other features associated with an increased risk for completed suicide include male sex, being single or living alone, and having prominent feelings of hopeless- ness. The presence of borderline personality disorder markedly increases risk for future suicide attempts.
Many of the functional consequences of major depressive disorder derive from individual symptoms. Impairment can be very mild, such that many of those who interact with the af- fected individual are unaware of depressive symptoms. Impairment may, however, range to complete incapacity such that the depressed individual is unable to attend to basic self- care needs or is mute or catatonic. Among individuals seen in general medical settings, those with major depressive disorder have more pain and physical illness and greater de- creases in physical, social, and role functioning.
Manic episodes with irritable mood or mixed episodes. Major depressive episodes with prominent irritable mood may be difficult to distinguish from manic episodes with irritable mood or from mixed episodes. This distinction requires a careful clinical evalua- tion of the presence of manic symptoms.
Mood disorder due to another medical condition. A major depressive episode is the appropriate diagnosis if the mood disturbance is not judged, based on individual history, physical examination, and laboratory findings, to be the direct pathophysiological conse- quence of a specific medical condition (e.g., multiple sclerosis, stroke, hypothyroidism).
Substance/medication-induced depressive or bipolar disorder. This disorder is distin- guished from major depressive disorder by the fact that a substance (e.g., a drug of abuse, a medication, a toxin) appears to be etiologically related to the mood disturbance. For ex- ample, depressed mood that occurs only in the context of withdrawal from cocaine would be diagnosed as cocaine-induced depressive disorder.
Attention-deficit/hyperactivity disorder. Distractibility and low frustration tolerance sode; if the criteria are met for both, attention-deficit/hyperactivity disorder may be diag— nosed in addition to the mood disorder. However, the clinician must be cautious not to overdiagnose a major depressive episode in children with attention-deficit/hyperactivity disorder whose disturbance in mood is characterized by irritability rather than by sadness or loss of interest.
Adjustment disorder with depressed mood. A major depressive episode that occurs in response to a psychosocial stressor is distinguished from adjustment disorder with de- pressed mood by the fact that the full criteria for a major depressive episode are not met in adjustment disorder.
Sadness. Finally, periods of sadness are inherent aspects of the human experience.
These periods should not be diagnosed as a major depressive episode unless criteria are met for severity (i.e., five out of nine symptoms), duration (i.e., most of the day, nearly ev- ery day for at least 2 weeks), and clinically significant distress or impairment. The diagno- sis other specified depressive disorder may be appropriate for presentations of depressed mood with clinically significant impairment that do not meet criteria for duration or se- verity.
Other disorders with which major depressive disorder frequently co-occurs are substance— related disorders, panic disorder, obsessive-compulsive disorder, anorexia nervosa, buli- mia nervosa, and borderline personality disorder.
Diagnostic Criteria 300.4 (F34.1)