Re: Evolution, aggression, and men: Hormones matter?

Stephen M. Gardner (
23 Jul 1995 16:07:52 -0500

In article <>,
>The cause of depression is not known. I'm not familiar with Panksepp.
>Anyway, my addendum was also simplified. What happens is that there is
>a depletion of available norepinephrine (NE) at the synapse. This
>depletion leads to an up-regulation of pre- and post-synaptic NE re-
>ceptors. The system now has increased sensitivity to NE, but it is
>not available in sufficent concentrations. Pharmacological treatment
>usually has involved the use of NE-reuptake blocking drugs. These drugs
>increase the NE levels in the synapse and eventually result in a down-
>regulation of the NE receptors.
Not to quibble but the more modern anti-depressants work
by blocking serotonin re-uptake. The older tricyclics
blocked both NE and serotonin reuptake. It is my understanding
that this is why the more modern SSRI antidepressants cause
fewer side effects. They are very specific and the serotonin
system has a lot to do with depression.

> The physiological effects of the drugs
>I have described are "immediate" in that it can occur in a few hours.
>Paradoxically, the behavioral outcome;i.e., the end of the feeling of
>depression, takes anywhere from 2-6 weeks. This indicates that the treatment
>and the physiology do not adequitely describe what is depression. It
>is rather(!) more complex and the subject of intense study.
Actually, the buildup of the SSRIs in the brain (as opposed to
the serum levels) is rather slow from what I have heard.
That is not to say that depression is a simple reflection
of low serotonin levels but that the pharmacokinetics
is kind of funky too. Interestingly enough, development
of the SSRIs has resulted in a lot of rethinking of
theories on the part of the psychiatric community.