The first-line treatment for mild to moderate depression is psychotherapy or antidepressant medication because these approaches effectively address the underlying symptoms while minimizing risks and side effects. Psychotherapy, particularly cognitive-behavioral therapy (CBT), provides coping strategies and alters negative thought patterns, making it highly effective for mild cases. When symptoms persist or are more severe, antidepressants, such as SSRIs, help correct neurochemical imbalances associated with depression. This combination optimizes patient outcomes and quality of life. Other options like electroconvulsive therapy or benzodiazepines are reserved for severe, resistant, or specific cases, not as initial treatments.

Reference: Kaplan & Sadock’s Synopsis of Psychiatry, Sadock, 12th Edition.