This is completely and utterly wrong. Psychiatric treatment varies in effectiveness, but there are drugs like lithium which have a fast and marked effect on the diseases they treat (e.g. Bipolar disorder, a crippling illness if left untreated). Depression drugs are less effective overall than other psychiatric illnesses, but even these have proven clinical effects in huge double-blind trials.

You really should read up on the literature, or hang around some people with serious mental health problems before spewing such garbage.