Used primarily in the treatment of depression, particularly in patients who do not respond to other antidepressants. It helps improve mood, reduce anxiety, and increase energy levels by restoring the balance of certain natural substances in the brain. Due to its activating effects, it may be preferred in patients with depression accompanied by fatigue or excessive sleepiness. Also occasionally used off-label for conditions like chronic pain, attention deficit disorders, and certain types of neuropathy, though such uses are less common. Its application is limited by side effects, especially in elderly patients, and requires careful monitoring.