Mirtazapine is primarily used as an antidepressant to treat major depressive disorder. It works by increasing the levels of certain neurotransmitters in the brain, such as norepinephrine and serotonin, which helps improve mood and reduce symptoms of depression.

In addition to its antidepressant effects, it is also prescribed for anxiety disorders, insomnia, and post-traumatic stress disorder (PTSD) due to its sedative properties. It is particularly beneficial for patients who experience difficulty sleeping or have lost their appetite, as it can stimulate hunger and promote weight gain.

Mirtazapine is sometimes used off-label to manage chronic pain, especially neuropathic pain, and to alleviate nausea and vomiting in patients undergoing chemotherapy. Its ability to block specific receptors in the brain makes it versatile in addressing multiple conditions beyond its primary use in depression.

It is typically taken orally in tablet or orally disintegrating form, and the dosage is adjusted based on the patient’s response and tolerance. Due to its sedative effects, it is often recommended to take it in the evening or before bedtime.