I have severe depression for last 8 mos. snri drugs are not working, what conditions can be causing my depression, what should i get tested for?

See your doctor : Depression not responding to an SNRI requires careful evaluation. Lab test to rule out thyroid dysfunction is important. Your doctor may switch to another class of antidepressant. Another option is augmentation with lithium or antipsychotic such as Abilify (aripiprazole). Treatment resistant depression could be undiagnosed Bipolar depression. Talk to your doctor who knows your history. Avoid use of alcohol.