Cognitive-behavioral therapy
CBT is a common treatment for mood disorders.  It is popular because it works well, has a clear structure, and is based on common sense. Research shows that CBT works better than any other treatment for people with depression and anxiety. After completing 5 - 15 modules of CBT, 50 - 75% of people with depression and anxiety feel better.  Medication alone also works, but science still does not understand how these medications affect the brain and body over time.  Also, some evidence says that CBT costs less than medication in the long run.  However, when medication and CBT are used together, patients with mental illnesses get the best results.  In particular, antidepressants paired with CBT could prevent people with depression from getting depressed again in the future.