A research study found that out of 129 patients with treatment resistant depression, 82.9% had another mental disorder, 82.2% were diagnosed with a personality disorder, and 69.8% had severe physical health ailments. In addition, 44.9% attempted suicide at least once in their lives, 79.8% experienced significant childhood trauma, and a vast majority reported a poor quality of life. These results show that TRD is a complex form of depression that requires further research.