Two major depressive disorders are major depressive disorder and persistent depressive disorder. Major depressive disorder is a sad mood or loss of interest and pleasure with at least 5 symptoms present. Persistent depressive disorder is an individual having a depressed mood for at least 2 years and 1 year for children or adolescents. The epidemiology of depressive disorders suggests that depression is common with prevalence over 10% that varies by culture and gender. The consequences of these depressive disorders is their high comorbidly rate and risk for other disorders.
Major depressive disorder is a sad mood or loss of interest and pleasure with at least 5 symptoms present. Symptoms include sleeping too much or too little, psychomotor retardation or agitation, poor appetite and weight loos, or increased appetite and weight gain, loss of energy, feelings of worthlessness or excessive guilt, difficulty concentrating, thinking, or making decisions, or recurrent thoughts of death or suicide. These symptoms are present nearly every day, most of the day, and for at least two weeks and are distinct from and more severe than a normative response to significant loss. Major depressive disorder I is episodic where symptoms tend to dissipate over time and recurrent where once depression occurs, future episodes are likely. Among people with a first depressive episode 15% report persistent depressive symptoms and 50% report at least one additional episode. Major depressive disorder II is useful to consider depression symptoms as a continuum of severity and patients may present with quite varied symptom presentations.
Persistent depressive disorder is an individual having a depressed mood for at least 2 years and 1 year for children or adolescents. Two symptoms must also be present such as poor appetite or overeating, sleeping too much or too little, low energy, poor self-esteem, trouble concentrating or making decisions, or feelings of hopelessness. These symptoms must also not clear for more than 2 months at a time and bipolar disorder must not be present.
In the epidemiology of depression, depression is common with a lifetime prevalence of 16.2% MDD and 5% of depression for more than 2 years. Depression is twice as common in women as in men and three times as common among people in poverty. Prevalence varies across cultures with MDD being 6.5% in China and 21% in France and the addition of cultural factors playing an important role in depression rates. Symptoms vary across cultures with the focus on somatic symptoms in ethnic minorities in the US and people from Latin America and some Asian countries. The age of onset is early 20s but has decreased over the past 50 years. The consequence of depression is the co-morbidity rate of 5-30% with MDD experiencing PDD and 60% of those with MDD also meeting the criteria for anxiety disorder at some point.