Nortriptyline is primarily used as an antidepressant to treat symptoms of depression. It belongs to the class of tricyclic antidepressants and works by affecting the balance of certain natural chemicals in the brain, such as serotonin and norepinephrine. It helps improve mood, energy levels, and feelings of well-being in patients with depression. Additionally, it is sometimes prescribed for managing chronic pain conditions, such as neuropathic pain or migraines, due to its ability to alter pain perception. In some cases, it is also used to treat anxiety disorders or to help with smoking cessation by reducing withdrawal symptoms. The dosage and duration of treatment are tailored to the individual’s condition and response to therapy.