Bupropion XL 150 mg is an extended-release tablet that is used to treat depression and seasonal affective disorder (SAD), which is a type of depression that occurs each year. It may also be used to prevent SAD. Bupropion XL 150 mg works by restoring the balance of certain natural substances, such as dopamine and norepinephrine, in the brain. It is also used as part of a support program to help people stop smoking. However, it is important to note that bupropion XL 150 mg should not be taken with a monoamine oxidase (MAO) inhibitor, and it is very important that you receive only one prescription at a time for bupropion. If you are already taking medicine for depression or to help you stop smoking, discuss this with your doctor before taking bupropion. Additionally, bupropion XL 150 mg may cause some people to be agitated, irritable, or display other abnormal behaviors. If you have any questions or concerns about taking bupropion XL 150 mg, talk to your doctor or pharmacist.