The following are some of the reasons 'Chemical In-balance' theory has become so prevalent.
** People prefer a 'physical disease' label rather than a 'Mental Illness' tag. If depression has a physical cause then it isn't necessarily a "Mental Illness", thereby removing the stigma.
** Medical insurers are primarily concerned with cost, and they want to discourage treatments (such as psychotherapy) that may involve many contact hours and considerable expense. Their control over payment schedules enables insurance companies to shift treatment toward drugs and away from psychotherapy.
** The motivation of the pharmaceutical companies should be fairly obvious. As mentioned previously, the market for antidepressant drugs is now $12 billion. All publicly traded for-profit companies are required by law to increase the value of their investor’s stock. Perhaps it goes without saying, but it is a simple fact that pharmaceutical companies will do anything they legally (and sometimes illegally) can to maximize revenues.
** The motivation of psychiatrists to accept the chemical imbalance theory is somewhat more subtle. Starting around 1930, psychiatrists became increasingly aware of growing competition from nonmedical therapists such as psychologists, social workers and counselors. Because of this, psychiatrists have been attracted to physical treatments like drugs and electroshock therapy that differentiate them from nonmedical practitioners. Psychiatry may be the least respected medical specialty (U.S. General Accounting Office report). Many Americans rejected Fruedian talk therapy as quackery, and the whole field of psychiatry lacks the quality of research (randomized, placebo-controlled, double-blind experiments) that serves as the gold-standard in other branches of medicine.
Of course there are also many “benefits” to going along with the conventional “chemical imbalance” theory, such as free dinners, symphony tickets, and trips to the Caribbean; consultancy fees, honoraria and stock options from the pharmaceutical companies; and a much larger, growing private practice as the $20 billion spent by drug companies on advertising brings patients to the office. Psychiatrists are just human, like the rest of us, and not many of them can resist all of these benefits.
