Hello, Depression without recovery in between for so long even when you are compliant with medication points out towards some root cause behind your symptoms. What I would suggest is to rule out other possibility causing depression such as thyroid, vitamin or having bipolar mood disorder. Sometimes we miss out hypomania episode as depression covers it. A mood chart will benefit you in that. Adding a mood stabilizer like lithium will cover your bipolar illness and augment your antidepressant treatment as well. Before trying antipsychotics you can discuss with your psychiatrist regarding what all class of antidepressants are already used, adding lithium or thyroid if augmentation is required. You can consult me for further help.

Atypical antipsychotics are useful if there are psychotic symptoms. When depressive symptoms are not improving, first step is usually to increase the dose of antidepressant. If that does not help, then add another antidepressant or switch to another antidepressant. If this does not work , then augment with agents like thyroxine, lithium etc. Somatic treatments like ect, rTMS also used. Combining psychotherapy with antidepressant helps at times.