There are many different treatments for depression, including various forms of therapy, medication, electroconvulsive therapy, light therapy, and lifestyle changes (changes in diet, exercise, etc).
Treatments for depression include use of antidepressants, electroconvulsive therapy ECT, cognitive behavior therapy, rational emotive therapy, support and understanding.
Antihypertensive drugs, steroids, muscle relaxants, anticancer drugs, and opioids, as well as extensive surgery such as a coronary bypass, may lead to depression.