Depression is affects approximately 350 million people worldwide, and approximately 7% of the US population. The primary objective is to treat to remission, and if they do not are considered to be treatment resistant. Resistance is often considered the failure of 2 adequate treatment trials. It is believed that approximately 45% of patients are treatment resistant, according to a major study. Risk factors for treatment resistance include psychiatric comorbidies, medical comorbidies, and genetic preponderance. 

If you are not responding to medication it is imperative to reevaluate diagnosis, complete an adequate trial of at least 4-6 weeks on a medication, and adhere to directions in taking medication.