Risperdal is a drug manufactured by the Johnson & Johnson subsidiary, Janssen Pharmaceuticals and approved initially in 1993 for use in the treatment of adult schizophrenia. Risperdal works by limiting the nerve communication in the brain including the neurotransmitter dopamine. When dopamine is removed from the brain, the muscles and nerves which control movement and coordination can be negatively affected. Information processing can also be disrupted, leading to problems with memory and concentration.