You're a great thinker! I've had similar thoughts about some of the SSRIs and how they are used. I believe that we may shift one set of chemical mediators and thereby shift response and reward probabilities. A positive feedback spiral results that accounts for much of the apparent cure. Failure of the social outcomes means a partial response to the medication or it could mean that the client is genetically different from most of us.
My cautious interpretation is that sertraline, whether prescribed by a family practitioner or a psychiatrist, can kick people into a mild hypomania. Some evolutionary talk about winning, about dominance, about alliances and hierarchies with respect to peers and to lovers helps target social effort. Behavior variability increases, clients are reinforced, and "winning" kick them into the hypomania once there are some victories and some alliances.
I mention this possibility because some dysthymic clients do respond poorly to medications. Such people may have genetic traits that are different from the responders. They may also be in the wrong niche for their particular talents and still lose the social and vocational contests. Their Psych Adaptations will continue to be accurate and to indicate a low position on the dominance scale, a position that discourages any of us even with an SSRI platform. There's substantial individual variability in the effects of sertraline or any other medication; however, I no longer believe the variance is entirely within chemistry's domain. Clients need some honest victories, not prattle about their self-esteem.
I sometimes become annoyed with sertraline's being a prescription item; however, some client's sensitivity to it as well as their interpretations of its effects and the interactions between sertraline and environmental options remind me that professional advice is a necessity and that such direction may not always be available from a family doc. The same considerations hold for St. Johnís Wort as well as for caffeine.
Sally lied, skipped school, and complained of physical and mental restlessness; there was a recurring history of mania in her family. Her parents were struck by her apparent lack of "remorse" after each of her incidents. She agreed to take a quarter mg of risperidone twice a day and began eating every chance she got. She was sleepy but accurately performed tasks and school work. She quit lying to her parents and started doing homework so that she could graduate with the rest of her class. She seemed less resentful when accepting the word "No."
However, she became embarrassed and annoyed that she started to cry when discussing personal problems; annoyed that she talked with another female about social difficulties rather than with a guy.
I cautioned her that her largest challenge would be her comfort level with being contrite rather than hostile and annoyed, with her accepting the relatively new sensation of remorse instead of labeling it a weakness as she had for easily a decade. Manics often don't care for feeling weak; she may not either. The choice is hers both now and in her future. Meanwhile, the rest of us have to consider the notion of reducing someone's self-esteem -- a reversal of predominant psychiatric-social thinking for 15 years -- for their future social gains.