The depressive disorder may begin at any age, with a mean age of the early to mid 20's

DEPRESSIVE DISORDER


The  depressive disorder may begin at any age, with a mean age of the early to mid 20's. Some people have isolated episodes separated by many years of depressive symptoms, while other groups of episodes, and some have more frequent episodes as they age. After the first episode of this disorder, there is a 60% chance of having a second episode. After the second episode, there is a 70% chance of having a third, and after the third episode, there is a 90% chance of having a room. About 5% to 10% of individuals with this disorder eventually develop bipolar I disorder Sudden onset of severe depression, especially psychotic symptoms and disorders in a young person without prepubertal psychopathology is more likely to provide a pole development. Family history of bipolar disorder may also suggest further development of bipolar disorder.


In two thirds of cases, of major depressive episode ends with a full recovery. For people who have only a partial recovery, there is a greater likelihood of developing further episodes of this disorder and to follow the pattern of partial recovery intercurrent. People who have pre-existing Dysthymic Disorder prior to the onset of the disease are more likely to have other major depressive episodes, have the poorest recovery intercurrent, and are more difficult to treat major depressive episodes. A year after the diagnosis of this disorder, 40% have no mood disorder, 20% partially recovered and 40% still have symptoms that are severe enough to meet all the criteria for a major depressive episode .

Initial severity of major depressive disorder appears to predict persistence. Chronic diseases are also common risk factor for more persistent episodes. Among major depression later in life, there is no evidence of recurrence of the white matter hyperintensity associated with cerebrovascular disease. These depressions are associated with increased vascular neuropsychological impairment and poor responses to the treatments in question.


Episodes of major depressive disorder often follow a severe psychosocial stressor, for example in the death of a loved one or divorce. Stress factors can play a more important role in the precipitation of the first or second section of this disorder and then play in the pathogenesis of fewer episodes. Chronic diseases and drug addiction (especially alcohol or cocaine) may contribute to the emergence or worsening of the disease.


Biological first-degree relatives of individuals with this disorder, the largest is 1.5 to 3 times more likely to develop severe depression. They also have an increased risk of alcohol dependence, anxiety disorder (eg, panic disorder, social phobia), and Attention-Deficit/Hyperactivity Disorder in comparison with the population. The lifetime prevalence of this disease in the general population is 10% and 25% of women and 5% to 12% of men. Each year, 5% to 9% of women have this disorder, and 2%, 3% of men have it. Prevalence of this disorder appear to be unrelated to ethnicity, education, income or marital status. In childhood, boys and girls are equally affected. However, in adolescence and adulthood, the disorder is twice as common in women than in men.


No laboratory findings can proved the diagnosis of this disorder. Sleep EEG abnormalities are evident in 40% to 60% of ambulatory patients and in up to 90% of patients hospitalized with this disorder. The most common abnormalities of sleep EEG are reduced rapid eye movement [REM] latency, increased REM density, reduced slow wave sleep and reduced sleep continuity. In some depressed individuals experience hormonal disorders were observed, including increased secretion of glucocorticoids (eg, high urinary levels of free cortisol or dexamethasone nonsuppression plasma cortisol) and blunted growth hormone, thyroid-stimulating hormone responses and prolactin at different testing challenges. In some individuals, functional analysis of the brain showed increased blood flow in limbic and paralimbic regions and decreased blood flow in the lateral prefrontal cortex. Depression, beginning in late life is associated with changes in brain structure, including the periventricular vascular changes (indicating vascular depression).


Some other theories focus on changes in the levels of neurotransmitters, including abnormal regulation of cholinergic neurotransmission, catecholaminergic (noradrenergic or dopamine) and serotonin (5-hydroxytryptamine). neuroendocrine dysregulation may be a factor, with emphasis on three axes: the hypothalamic-pituitary-adrenal hormone hypothalamic-pituitary-thyroid and involved psychosocial growth. factors seem. major life stresses, including separation and loss, often preceded by episodes of major depression, but such events do not usually cause severe depression duration, except in people predisposed to mood disorders.


People who have had an episode of major depression are at high risk for subsequent episodes of depression. Those who are introverted and have strong tendencies may be more prone to developing a depressive disorder. These people often do not develop the social skills necessary to adapt to life stress. Depression can also develop in people with other mental disorders. Women are more at risk, but no theory explains why. Possible factors include increased exposure or increased response to daily stresses, higher levels of monoamine oxidase (the enzyme that breaks down neurotransmitters are considered important for the mood), more thyroid dysfunction, and endocrine changes that occur with menstruation and menopause. In the post-partum depression (see post-partum care: postpartum depression), symptoms develop within 4 weeks after delivery, endocrine changes are involved, but the exact cause is unknown.


In seasonal affective disorder ( SAD ), symptoms can develop in a seasonal pattern, usually in fall or winter, the disease tends to occur in climates with harsh winters or long and depressing. The symptoms or disorders that may accompany various physical disorders and adrenal gland disorders including thyroid tumors, benign brain tumors, stroke, AIDS, Parkinson’s disease and multiple sclerosis . Some medications such as corticosteroids, certain β-blockers, interferon, and reserpine, can also cause depression. The abuse of certain recreational drugs (eg alcohol, amphetamines) may cause or accompany depression. The toxic effects or withdrawal of the drug can cause transient depressive symptoms.