Used primarily as an antidepressant in the treatment of major depressive disorder. It functions as a tetracyclic antidepressant with strong antagonistic effects on serotonin, histamine, and adrenergic receptors, helping to regulate mood and reduce anxiety. Due to its sedative properties, it is also prescribed for insomnia and anxiety disorders, especially in elderly patients. Its low anticholinergic activity makes it a favorable option for patients who cannot tolerate other antidepressants with stronger side effect profiles. Additionally, it has been used off-label for appetite stimulation and weight gain in certain clinical conditions.