Risperidone is an atypical antipsychotic medication primarily used to treat schizophrenia, bipolar disorder, and irritability associated with autism spectrum disorder (ASD). It works by blocking dopamine D2 and serotonin 5-HT2A receptors, helping to regulate neurotransmitter activity in the brain. This action reduces hallucinations, delusions, disorganized thinking, and mood instability, making it an effective treatment for schizophrenia and bipolar disorder. In bipolar disorder, risperidone helps manage manic episodes by stabilizing mood and reducing aggression, impulsivity, and hyperactivity. Due to its ability to modulate serotonin levels, it also has a calming effect, which makes it useful for treating irritability, aggression, and self-injurious behaviors in children with autism.

Risperidone is generally well-tolerated but may cause side effects such as weight gain, drowsiness, dizziness, and increased appetite. It is also associated with a higher risk of extrapyramidal symptoms (EPS), such as muscle stiffness, tremors, and restlessness, particularly at higher doses. Long-term use may increase the risk of metabolic issues, including diabetes and high cholesterol, requiring regular monitoring. Despite these potential side effects, risperidone remains one of the most effective and widely prescribed antipsychotics, offering significant symptom relief and improved quality of life for individuals struggling with schizophrenia, bipolar disorder, and autism-related behavioral challenges.