New York: Identifying and treating metabolic deficiencies in individuals suffering from depression can help improve symptoms and also lead to remission in cases where antidepressant medications and therapy does not work, says a study. Depression is a mood disorder causing a persistent feeling of sadness and loss of interest. It is also one of the most common mental disorders. “Unfortunately, at least 15 per cent of patients don’t find relief from conventional treatments such as antidepressant medications and psychotherapy,” said lead researcher Lisa Pan, Professor at University of Pittsburgh in Pennsylvania, US Depression is also the cause of more than two-thirds of suicides that occur annually. In some patients, medications do not work because of metabolic abnormalities interfering with brain function, the researchers said. The results indicate that there may be physiological mechanisms underlying depression that can be used to improve the quality of life in patients with this disabling illness. The study was inspired by a teenage boy with a history of suicide attempts and long-standing depression.