SIR: Human immunodeficiency virus (HIV) is commonly associated with many psychiatric and behavioral symptoms. Although dementia is the most significant complication, HIV disease often mimics functional psychiatric disorders such as affective disorders and psychosis.^R5P9041601 Because HIV often invades the brain early in the illness, behavioral changes may be the presenting symptoms.^R5P9041602 We describe below a patient with HIV disease who, although displaying mild cognitive impairment, presented primarily with prominent delusions of misidentification.

The patient is a 51-year-old white man with a 14-year history of asymptomatic HIV infection who was admitted to the psychiatric inpatient unit for evaluation of mental status change. Symptoms, which were present for 2 weeks prior to admission, included delusions of misidentification, paranoid delusions, irritability, anxiety, insomnia, decreased appetite, and emotional lability. Lorazepam had been started on an outpatient basis at l mg bid without success. Other than an uncomplicated and successfully treated pneumonia, the patient had no AIDS-related illness or other medical problems prior to admission. He had no history of psychiatric illness or substance abuse.

During the initial evaluation, the patient was quite agitated and was unable to sit for the examination. He believed the female psychiatric resident interviewing him was his male internist in disguise and repeatedly attempted to pull her hair, believing that she was wearing a wig.

A complete neuropsychiatric workup was completed. Cytomegalovirus infection was ruled out, lumbar puncture was negative, pulse oximetry showed 96% oxygen saturation, urine drug screen was negative, a CT scan of the head without contrast was negative, and routine laboratory tests and ECG were normal. A SPECT scan showed significant asymmetry, demonstrating increased flow to the left caudate and left thalamus as well as cortical atrophy. Neuropsychological testing suggested moderate to severe impairment in areas of attention and concentration, fine motor coordination, memory, executive functioning, and impulse control.

The patient's psychosis was felt to be secondary to HIV infection. He was started on risperidone titrated to 3 mg bid in addition to the lorazepam. On these medications he achieved a complete resolution of symptoms of psychosis and was discharged from the hospital after 21 days.

At initial follow-up the patient remained symptom-free. However, because of his bradykinesia and facial masking, risperidone was decreased to l mg bid. Neuropsychological testing done at 4-month follow-up revealed only mild deficits in attention and concentration and mild to moderate impairment on tests of fine motor speed, coordination, and novel problem solving.

This case of successful use of risperidone in a patient with delusional disorder due to HIV disease was especially remarkable for the patient's robust and sustained response to the drug. In reviewing the literature, we could find no other case reports describing the efficacy of risperidone in AIDS-related psychiatric symptoms and no reports of delusions of misidentification associated with HIV infection. Further research on psychotic disorders due to HIV disease and their response to risperidone or other atypical neuroleptics would be most beneficial.