They hardly affect normal people at all, but instead interact with whatever has gone wrong with the brain during a depressive illness and normalize it. For patients with both mania and depression, mood stabilizing medications, such as Lithium, treat both depression and mania. When taken on a continuing basis, they can prevent or decrease the severity of re-occurrences. Many people pooh pooh the use of antidepressants, claiming that they are just 'feel good drugs,' but that is simply not the case. They are feel well drugs.
Side effects can be a problem but are usually manageable.
When a person sees a psychotherapist, he or she should feel comfortable and in good hands. This is just as important when consulting a doctor primarily for medication. The patient must not be rushed and should be free to discuss all of their concerns. Otherwise side effects may lead the patient to secretly take less medication, to their detriment. A patient dissatisfied with their doctor or their progress should definitely get a second opinion.