Posted by katekite on June 28, 2002, at 18:50:30
In reply to Antipsychotics as antidepressants?, posted by skills on June 28, 2002, at 10:49:08
Its complicated and honestly I don't think they really know. Here is a quote from www.acnp.org, a drug book site:
Contrary to expectations, given the antidepressant effects of DA agonists, there is also clear evidence that under certain circumstances, neuroleptics, which are DA receptor antagonists, are also active as antidepressants [73, 92]. One potential resolution of this apparent paradox (which will be discussed further below) is that neuroleptics may be antidepressant only at low doses, which act preferentially as DA autoreceptor antagonists and so increase DA turnover. This hypothesis has been advanced in particular in relation to certain atypical antidepressants, such as sulpiride, which are said to have 'activating' properties [59]. Antidepressant effects of sulpiride are seen in a dose range of 50-150mg/day, which is considerably lower than the typical antipsychotic dose of 800-1000mg/day. A DA-activating effect of sulpiride at low doses is supported by the finding that low doses of sulpiride antagonized the sedative actions of apomorphine in human subjects [99].
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What this says is that anti-psychotics at low doses may act on dopamine neuron receptors to actually activate those neurons... increasing not decreasing transmission. Paradoxical. The term 'anti-psychotic' is clearly out-dated since they do a lot more than that, in any case.
Kate
poster:katekite
thread:110987
URL: http://www.dr-bob.org/babble/20020628/msgs/111004.html