which medicines can prove to be helpful against this disorder?
Omega-3 fatty acids fish oil supplements, celecoxib are few
Major depressive disorder
There is some evidence that omega-3 fatty acids fish oil supplements containing high levels of eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) are effective in the treatment of, but not the prevention of major depression. However, a Cochrane review determined there was insufficient high quality evidence to suggest omega-3 fatty acids were effective in depression. There is limited evidence that vitamin D supplementation is of value in alleviating the symptoms of depression in individuals who are vitamin D-deficient. There is some preliminary evidence that COX-2 inhibitors, such as celecoxib, have a beneficial effect on major depression. Lithium appears effective at lowering the risk of suicide in those with bipolar disorder and unipolar depression to nearly the same levels as the general population.
what does single episode major depressive disorder mean UNANSWERABLE what are symptoms of  this disorder? Low mood, symptoms of psychosis; like delusions and hallucinations are some of them how it is caused? Childhood abuse, either physical, sexual or psychological are all risk factors how this can be prevented? Eating large amounts of fish, Behavioral interventions, such as interpersonal therapy and cognitive-behavioral therapy
wiki:1591196
Major depressive disorder [SEP] Other medications
There is some evidence that omega-3 fatty acids fish oil supplements containing high levels of eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) are effective in the treatment of, but not the prevention of major depression. However, a Cochrane review determined there was insufficient high quality evidence to suggest omega-3 fatty acids were effective in depression. There is limited evidence that vitamin D supplementation is of value in alleviating the symptoms of depression in individuals who are vitamin D-deficient. There is some preliminary evidence that COX-2 inhibitors, such as celecoxib, have a beneficial effect on major depression. Lithium appears effective at lowering the risk of suicide in those with bipolar disorder and unipolar depression to nearly the same levels as the general population.