Author Question: Provide three pieces of evidence to support the dopamine hypothesis of schizophrenia. What will ... (Read 73 times)

dmcintosh · **on:** Jun 22, 2018

Provide three pieces of evidence to support the dopamine hypothesis of schizophrenia.

What will be an ideal response?

Question 2

Compare the conventional (typical) antipsychotics, such as chlorpromazine (Thorazine) and haloperidol (Haldol), with the atypical antipsychotics, such as clozapine Clozaril and risperidone (Risperdal),

in terms of their efficacy in the treatment of schizophrenia and most common and important side-effects.

What will be an ideal response?

triiciiaa · **Reply #1 on:** Jun 22, 2018

Answer to Question 1

Drugs that increase extracellular levels of dopamine, e.g., cocaine, amphetamine, PCP, MAOIs can induce schizophrenia-like symptoms or exacerbate those with schizophrenia, whereas drugs that deplete DA levels or competitively block DA receptors or reduce DA release generally reduce the symptoms in schizophrenics. Some schizophrenics have higher density of DA receptors than normal individuals in some areas of the brain.

Answer to Question 2

Although they all show approximately the same efficacy with respect to reducing the positive symptoms of schizophrenia, atypical antipsychotics may be more effective in reducing the negative symptoms. Atypical antipsychotics may also be effective in about a third of those patients that do not respond to conventional antipsychotics. The wide variety of disturbing extrapyramidal motor side effects noted with the conventional antipsychotics are minimal with Risperdal and absent with Clozaril, including tardive dyskinesia. However, the much higher incidence of agranulocytosis with Clozaril requires periodic (and expensive) blood tests; otherwise, opportunistic infections can be lethal to the person.