Medications and psychotherapy can both be useful, with research showing relatively equivalent efficacy between the two in depression (although the pharm studies have really begun coming under fire recently). The issue is that we don't know nearly enough about how or why the medicines work, so any theory about "chemical imbalance" is just that at this point--theory, and may not represent the best or most accurate way of viewing what's going on.
I of course do believe that individuals struggling with symptoms of depression show altered brain activity compared to individuals not struggling with depression; saying otherwise would just be faulty, given that in the end, everything boils down to brain activity. I also believe that there are likely genetically-based components that may predispose one to being more likely to experience depressive symptoms, particularly in the presence of precipitating events (although these same predispositions are likely highly multi-faceted, may not be specific to depression, and may be protective against other conditions). Beyond that, though, we don't know nearly enough about how the brain works to say much of anything. Heck, we don't even truly understand all the mechanisms by which talk therapy works; we just know it does.
Regarding psychosis in particular--for those interested, you should look into the long-term efficacy research around anti-psychotic medications, as well as the advances in cognitive and behaviorally-based therapies in individuals struggling with severe and persistent mental illness.
I of course do believe that individuals struggling with symptoms of depression show altered brain activity compared to individuals not struggling with depression; saying otherwise would just be faulty, given that in the end, everything boils down to brain activity. I also believe that there are likely genetically-based components that may predispose one to being more likely to experience depressive symptoms, particularly in the presence of precipitating events (although these same predispositions are likely highly multi-faceted, may not be specific to depression, and may be protective against other conditions). Beyond that, though, we don't know nearly enough about how the brain works to say much of anything. Heck, we don't even truly understand all the mechanisms by which talk therapy works; we just know it does.
Regarding psychosis in particular--for those interested, you should look into the long-term efficacy research around anti-psychotic medications, as well as the advances in cognitive and behaviorally-based therapies in individuals struggling with severe and persistent mental illness.
