Effects of Antipsychotic Treatment on Emotion Perception Deficits in First-Episode Schizophrenia

Cognitive deficits are typically present at the onset of schizophrenia and show limited responsiveness to treatment (1, 2). However, it remains to be established whether emotional processing deficits are present at illness onset and whether antipsychotic treatment reduces such deficits. The current study addresses these issues by assessing emotion recognition in patients with first-episode schizophrenia before and after treatment.

Method

Subjects were recruited from the University of Illinois Medical Center. Thirteen patients experiencing their first episode of schizophrenia were diagnosed by using the Structured Clinical Interview for DSM-IV (SCID) (3). These patients had received 4 or fewer weeks of treatment with antipsychotic medication in their lifetime and had been unmedicated for at least 5 days before testing. Potential subjects were excluded if there was a history of substantial head injury, substance dependence, or systemic or neurological disorders that might affect symptom presentation or cognitive performance. After description of the study, written informed consent was obtained from all participating subjects.

Following baseline testing (described in the next two paragraphs), patients began treatment with risperidone (mean dose=3.38 mg, SD=2.01). Four individuals who were not responsive to risperidone or suffered substantial side effects were stabilized with alternate medications (one with ziprasidone 140 mg, one with aripiprazole 30 mg, and two with haloperidol at a mean dose 4.5 mg, SD=0.71). Subjects completed a second testing session when they were clinically stable (mean=31.3 days later, SD=8.35).

At the time of each testing, symptoms were assessed by using the Positive and Negative Syndrome Scale (4). SCID and Positive and Negative Syndrome Scale ratings were completed by trained clinicians with established reliability (kappa ≥0.75) who had no knowledge of task performance. Thirteen healthy subjects were recruited who did not meet criteria for any axis I disorder according to SCID results. These comparison subjects did not differ from the patient group in sex distribution, age, or parental education.

All subjects completed tests of the ability to perceive and discriminate emotional expressions from the Penn Computerized Neuropsychological Battery (5, 6). The emotional acuity task requires individuals to rate 40 black-and-white pictures of adult faces along a 7-point continuum of emotional intensity (happy to sad). The emotion differentiation task requires individuals to identify which of two faces in 40 pairs of black-and-white photographs shows more intense emotion. Data were converted to z scores by using means and standard deviations from normative data collected by the University of Pennsylvania group (6). Subjects also completed the two-subtest version of the Wechsler Abbreviated Scale of Intelligence (7) to evaluate general intellectual function.

Results

At the baseline assessment, patients with schizophrenia performed more poorly than healthy subjects on both the emotional acuity task (F=24.63, df=1, 24, p<0.001) and the emotional differentiation task (happy condition: F=20.73, df=1, 24, p<0.001, and sad condition: F=12.35, df=1, 24, p=0.002).

There was a robust decrease in symptom scores in the patient group from baseline to follow-up (positive symptoms: t=7.187, df=12, p<0.001; negative symptoms: t=3.241, df=12, p<0.01). There was no significant improvement on any of the emotion tasks after treatment (Figure 1). The effect sizes for change in emotion task performance after treatment were very small (emotional acuity task partial η²=0.001; emotion differentiation task happy condition partial η²=0.001, emotion differentiation task sad condition partial η²=0.01). Clinical improvement was unrelated to change in emotion task performance in the patients with schizophrenia (all p>0.20).

After treatment, negative symptom scores were highly correlated with performance impairments on the emotional acuity task in the patients with schizophrenia (r=–0.70, N=13, p<0.01). Positive symptom severity was not significantly correlated with task performance at either testing. When the analyses described here were repeated with IQ as a covariate, the same effects were observed.

Discussion

Deficits in emotional processing have long been considered a core deficit in schizophrenia (8). The results of the current study indicate that individuals with schizophrenia demonstrate deficits in emotional processing even at their first psychotic episode. Furthermore, these deficits were not significantly reduced by effective treatment with antipsychotic medication. Although the severity of emotional processing deficits was minimally related to symptom presentation during acute illness, these deficits were strongly linked to negative symptom severity after clinical stabilization. Because medication effectively reduced some aspects of negative symptoms, it may be that residual core persistent negative symptoms have a stronger linkage to emotional processing deficits.

The number of patients in the current study is limited, which reduced the power of the analyses. However, effect sizes of treatment on emotion task performance were so low that it is unlikely that statistical power considerations were responsible for the failure to identify improvement after treatment. Nonetheless, additional research with larger groups of subjects will be important to address this issue as well as whether other factors, such as chronicity of illness, may also influence these relationships.

Previous studies assessing medication effects on emotion perception have typically compared performance during treatment with atypical and conventional antipsychotic medications and found better performance with atypical antipsychotics (9, 10). Treatment studies assessing other aspects of cognitive performance in schizophrenia have also demonstrated somewhat better performance with atypical antipsychotics than conventional antipsychotic medications (11, 12). In the few studies comparing cognitive performance between unmedicated and medicated states in first-episode patients (1, 13), researchers have reported modest improvements in cognitive performance in select areas of functioning with atypical antipsychotic treatment. Schuepbach et al. (13) found that a decrease in negative symptoms with treatment was correlated with cognitive improvement and that persistent negative symptoms were associated with ongoing cognitive deficits.

The current data suggest that deficits in emotion perception are not significantly improved with effective atypical antipsychotic medication. Further, because emotion perception deficits were correlated after stabilization with negative symptoms, they may be another domain of deficit related to poorer functional outcome. Thus, they appear to represent an important target for clinical intervention.

Received June 21, 2004; revision received Sept. 22, 2004; accepted Nov. 8, 2004. From the Center for Cognitive Medicine, Department of Psychiatry, University of Illinois at Chicago. Address correspondence and reprint requests to Dr. Herbener, Cognitive Medicine, Department of Psychiatry, University of Illinois at Chicago, 912 S. Wood St., Chicago, IL 60612; [email protected] (e-mail). Supported by a grant from the National Alliance for Research on Schizophrenia and Depression (Dr. Herbener) and NIMH grants MH-067223 (Dr. Herbener) and MH-62134 (Dr. Sweeney).