Just as important as whether a drug relieves depression is how good a fit a drug is for the individual. A patient may find that a particular drug makes them feel the best they have in years, but the side-effects are intolerable.
Believe it or not, side-effects are not necessarily a bad thing. They can be good or bad, depending upon other illnesses or conditions that the patient has. If a patient has an eating disorder, a drug like Prozac that suppresses appetite may not be desirable. However, if a patient is diabetic, this same side-effect may be helpful in controlling their diabetes because they will have fewer cravings for forbidden foods.
Certain antidepressants have been found to be effective for conditions other than depression. If you have another condition along with depression that might be benefited by a particular antidepressant, a doctor may opt to try that medication. Wellbutrin is actually the same drug as Zyban, the popular stop-smoking medication. For a smoker, Wellbutrin might be a logical choice.

