Doctors are no different than you or I. They may have a higher IQ on average (probably), but they are human beings with the same weaknesses as everyone else. Doctors, however, are much more aware of the side-effects of these drugs, but these drugs are much more accessible to them, so the temptation is real.
Many medical doctors that are recent graduates put their full faith in scientific studies generated by pharmaceutical companies regarding new drugs. For example, for the longest time, the scientific community, including doctors believed that depression was caused by low levels of serotonin, and thus a "hormone imbalance". I believe that idea was debunked earlier this year; that is, depression is not caused by an imbalance of hormones. As a result of this blind trust, they may take antidepressants when they're feeling low and suffer the same consequences as everyone else.
Usually the earliest adopters of new medications are doctors or family members of doctors. For example, in the 1950's, thalidomide was released to prevent morning sickness in pregnant women. Canadian doctors (which were all male at the time), read the early studies and were convinced it worked, so they had their wives try it. Of those doctors wives that did try it, most of their children were born maimed at the limbs (again, this "blind trust" in the pharmaceutical industry) --
read more on that here.
Furthermore, I'm not certain the validity
of this article, but it states that 75% of med students are on antidepressants or stimulants.
Here’s what depressed doctors do (when nobody’s looking). Some drink alcohol, exercise obsessively, even steal psychiatric meds. Still more shocking—I discovered that 75% of med students (and new doctors) are now on psychiatric medications.