Genetics and stressful events are main causes of depression

CAUSES OF DEPRESSION

The biopsychosocial model suggest that biological, psychological and social factors all can play a role in causing stress-diathesis model depression.The specifies that depression results when an existing vulnerability or diathesis is activated by stressful life events.The preexisting weakness may be genetic, implying an interaction between nature and culture, or schema, because views on the world learned in childhood. These interactive models have been empirically support.For example, researchers in New Zealand has adopted a proactive approach to the study of depression over time showing how depression occurred in a cohort of persons researchers. The normal initially concluded that the variation between the serotonin transporter gene influences the chances that people who have dealt with very stressful life events are going to suffer from depression.

Very specifically, depression can follow these events, but it seems more likely to occur in people with one or two short alleles of 5-HTT gene. In addition, a Swedish study, the heritability of depression to the extent that individual differences in frequency are associated with genetic differences in the order of 40% for women and 30% for men and psychologists have proposed that Evolutionists the genetic basis of depression is deep in the history of changes of natural selection. A mood disorder-like substance-induced major depression has been linked to drug use or drug abuse in the long term, or the withdrawal of certain drugs and sedative hypnotics.

Biological

• Monoamine hypothesis

Most antidepressant medications raise one or more monoamines, neurotransmitters serotonin, norepinephrine and dopamine and synaptic gap between neurons in the brain. Some drugs directly affect the monoamine receptors. Serotonin has been predicted to regulate other neurotransmitter systems, reduced serotonin activity may allow these systems to act in strange and unpredictable. This hypothesis permissive, depression occurs when a small contribution to low serotonin norepinephrine, another neurotransmitter monoamines. Some antidepressants to improve the level of norepinephrine directly, while others raise dopamine, a neurotransmitter MAO third.

These results led to the hypothesis of monoamine depression. His contemporary, the monoamine hypothesis assumes that the lack of certain neurotransmitters responsible for the corresponding characteristics of depression: norepinephrine may be related to the vigilance and energy as well as anxiety, attention and interest life, serotonin to anxiety, obsessions, and forced, and dopamine is the focus, motivation, pleasure and reward, and of interest to the proponents of this theory role in life to recommend to choose an antidepressant with a mechanism that contributes significantly to the symptoms. irritable and anxious patients should be treated with SSRIs or norepinephrine reuptake inhibitors, and they feel powerless and enjoy life, and norepinephrine, and dopamine-enhancing drugs.

• Other theories

MRI of patients with depression revealed a number of differences in brain structure than non-depressed. Although there is some inconsistency in the results of the meta-analysis showed that there is evidence of smaller hippocampal volumes and increased the number of hyperintense lesions. Hyperintensities was associated with patients with late age of onset, and led to the development of the theory of vascular depression.

Psychological

There is various aspects of personality and its development seems to be an integral part of the deposit and persistent depression, with negative emotionality as a common precursor. Although depressive episodes are strongly correlated with adverse events, the style characteristic of a person to cope correlated with their resistance. In addition, low self-esteem and self-defeating or distorted thinking associated with depression. Depression is less likely to arise, and the faster the responsibility of those who are religious. It is not always clear which factors are causal or are the effects of depression, but depressed people who are able to think and challenge their thinking often show improved mood and self-esteem self.

Social

Poverty and social isolation are associated with an increased risk of some general mental health problems . Child maltreatment (physical neglect, emotional, sexual abuse) is associated with an increased risk of depressive disorders in the future. This link has good face validity as it was during the years of development a child learns to become a social being. Child abuse by caregivers is needed to distort the development of personality and create a much higher risk of depression and many other debilitating mental and emotional states. Disruptions in family functioning as parents (especially mothers), depression, severe marital conflict or divorce, death of a parent or other parental disorders are additional risk factors.

In adulthood is highly stressful life events associated with the occurrence of major depressive episodes. In this context seems life events associated with social rejection particularly related to depression. Evidence that a first episode of depression is more likely just before the stressful life events that are common between them is consistent with the hypothesis that people can become more aware of life stress over the Successive relapses of depression.

Evolutionary

From the perspective of evolutionary theory, major depression is the assumption in some cases, to increase the reproductive capacity of an individual. Evolutionary approaches to depression and developmental psychology to request the specific mechanisms by which depression may have been genetically incorporated into the human gene pool, representing the inheritance and prevalence of depression by proposing that certain components depression are adaptations, such as seizure-related behaviors and social status. current behavior can be explained as adaptations to regulate relations or resources, although the result may be inappropriate in a modern setting.

Drug and alcohol use

DSM-IV diagnosis of mood disorder can be done if the cause is believed to be due to the direct physiological effects of a substance, when a syndrome resembling major depression immediately suspected substance abuse or an adverse reaction is refers to the mood disorders induced by a substance, such as, alcoholism or alcohol abuse significantly increases the risk of developing major depression. Like alcohol, benzodiazepines, are nervous system depressants, and this class of drugs commonly used to treat insomnia, anxiety and muscle spasms. Like alcohol, benzodiazepines increase the risk of developing major depression. This increased risk may be partly due to the effects of drugs on neurochemistry, such as decreased levels of serotonin and norepinephrine. Chronic use of benzodiazepines can also cause or worsen depression or depression may be part of a protracted withdrawal syndrome.