Lithium 150 mg Bipolar Disorder Sitemap ) is a medication used for the treatment of bipolar disorder. It is available by prescription only and comes in several different forms and strengths, including:Although a higher dosage is necessary to control the severe symptoms of mania, a much lower dose is needed for maintenance treatment. Maintenance can be thought of as long-term control of bipolar disorder symptoms. If you do not have severe symptoms when starting lithium, your healthcare provider may recommend starting with a low dose (such as lithium 150 mg capsules) and slowly increasing it while frequently checking the level of lithium in the blood.