Monoamine Dysfunction Has Been Linked To Both Affective Disorders And Schizophrenia. Drawing Upon Relevant Evidence, Critically Evaluate The Role Of Monoamines In Each Of These Disorders
...Evidence, Critically Evaluate the role of Monoamines in each of these Disorders.
Assessment Number 2
Module Leader ' Dr Rebecca Jenks
Monoamine Dysfunction has been linked to both Affective Disorders and Schizophrenia. Drawing upon Relevant Evidence, Critically Evaluate the role of Monoamines in each of these Disorders.
Schizophrenia is a condition characterised by hallucinations, hearing voices and other dilutions which are known as the positive symptoms. Negative symptoms include social withdraw, flattened emotional response and an inability to experience pleasure. Prevalence is equally split between men and women; however there tends to be an earlier onset for men (20-28) than for women (26-32), Castle et al (1991). Lifetime occurrence is at around 0.55%, Goldner et al (2002) but variations have been found across culture, with urban areas often displaying higher incidence rates even when drugs use and other factors are accounted for, Van Os (2004).
Monoamine dysfunction has been given as a possible explanation of schizophrenia, with plenty of research for support. In particular the Dopamine Hypothesis, which suggests that raised levels of dopamine within the mesolimbic pathway is the cause, and has been noted in schizophrenic patients. Supporting this it was found that amphetamines which raise dopamine levels were found to exacerbate psychotic (positive) symptoms in schizophrenics, Laruelle (1996). In addition all of the early anti-psychotic drugs were chemicals that blocked the function of dopamine in some way, Tollefson and Sanger (1999). Also the ability of these drugs to block dopamine receptors positively correlates with clinical potency, Snyder et al (1978). Furthermore the path of the mesolimbic pathway means it travels firstly through the amygdala, where activation can lead to hallucinations, and secondly through the nucleus accumbens...
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