what schizophrenic symptoms are decreased by drugs that selectively block the d2 dopamine receptor
Dopamine hypothesis of schizophrenia A group of drugs called the phenothiazines, including antipsychotics such as chlorpromazine, has been found to antagonize dopamine binding (particularly at receptors known as D2 dopamine receptors) and reduce positive psychotic symptoms. This observation was subsequently extended to other antipsychotic drug classes, such as butyrophenones including haloperidol. The link was strengthened by experiments in the 1970s which suggested that the binding affinity of antipsychotic drugs for D2 dopamine receptors seemed to be inversely proportional to their therapeutic dose. This correlation, suggesting that receptor binding is causally related to therapeutic potency, was reported by two laboratories in 1976.[18][19]
Major depressive disorder Major depressive disorder affected approximately 216Â million people (3% of the world's population) in 2015.[5] The percentage of people who are affected at one point in their life varies from 7% in Japan to 21% in France.[4] Lifetime rates are higher in the developed world (15%) compared to the developing world (11%).[4] It causes the second most years lived with disability after low back pain.[16] The most common time of onset is in a person in their 20s and 30s.[3][4] Females are affected about twice as often as males.[3][4] The American Psychiatric Association added "major depressive disorder" to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980.[17] It was a split of the previous depressive neurosis in the DSM-II which also encompassed the conditions now known as dysthymia and adjustment disorder with depressed mood.[17] Those currently or previously affected may be stigmatized.[18]