A client diagnosed with schizophrenia is brought to the hospital from a group home where he became agitated, threw a chair at another client, and has been refusing medication for 8 weeks. The client exhibits a flat affect, is not caring for his hygiene, and has become increasingly withdrawn and asocial. The physician orders treatment with risperidone (Risperdal) to improve the client's negative and positive symptoms of schizophrenia. When evaluating the drug's effectiveness on the client's negative symptoms, the nurse should expect improvement in which of the following?