Olanzapine is an antipsychotic medication primarily used to treat conditions such as schizophrenia and bipolar disorder. It works by affecting certain chemicals in the brain, helping to improve mood, thoughts, and behavior. This medication can help reduce symptoms like hallucinations and delusions, making it easier for individuals to function in daily life. However, it may also cause side effects, including weight gain and drowsiness, so it is important for patients to discuss their treatment plan with a healthcare provider.