Posted by Kon on August 6, 2005, at 10:58:10
In reply to Re: We need placebo » Kon, posted by SLS on August 2, 2005, at 9:53:55
> My conjecture is not that people with mild depression are less responsive to antidepressants. It is that they are far more apt to respond to placebo.
If you read over the Kirsch review they claim that this is not true. In fact, they argue that the opposite may be the case. Interestingly in the Khan study you provided in your most recent post, the placebo response was as great in patients with severe depression as those with milder depression (with the lowest placebo response actually found in the milder depressives-though not statistically significant). The authors of the study you mention write:
"However, our results also suggest that the magnitude of placebo response was similar in the four subgroups (low moderate, high moderate, moderately severe and severe). This is in contrast to earlier findings that suggest that placebo response is higher in depressed patients with lower pre-treatment depressive symptoms."
So what does this mean? Greater response in severely depressed is due to actual drug effect and not differences in placebo response or are other confounding factors involved some of which the Khan mention:
"Finally, specific items on the HAM-D may induce greater antidepressant/placebo differences. For example, the 17-item HAM-D contains three questions pertaining to sleep. If a patient has difficulty with sleep or has few sleep-related problems, results of the HAM-D could be skewed depending on the amount of sleep problems the patient experiences.”
For instance if severely depressed have greater difficulty sleeping than less severely depressed and SSRIs improve this aspect then their better drug response may amount to this. I don't know if this is true but it's possible.
poster:Kon
thread:534296
URL: http://www.dr-bob.org/babble/20050803/msgs/538265.html