Impaired self-assessment in schizophrenia: Why patients misjudge their cognition and functioning

Domains of impaired introspective accuracy
Everyday functioning. The 3 global domains of everyday functioning are social outcomes, productive/vocational out­comes, and everyday activities, including residential independence/support for peo­ple with severe mental illness. Two areas of inquiry are used in self-assessing everyday functioning: (1) what are you doing now and (2) what could you do in the future? For people with schizophrenia, a related question is how perceived impairments in everyday functioning are associated with subjective illness burden.

People with schizophrenia report illness burden consistent with their self-reported disability, suggesting their reports in these domains are not random.⁸ Studies have consistently found, however, that these patients report:
   • less impairment on average in their everyday functioning than observed by clinicians
   • less subjective illness burden com­pared with individuals with much less severe illnesses.

Their reports also fail to correlate with cli­nicians’ observations.9 Patients with schizo­phrenia who have never been employed may report greater vocational potential than those employed full-time. Interestingly, patients who were previously—but not currently—employed reported the least vocational potential.¹⁰ These data suggest that experience may be a factor: individuals who have never worked have no context for their self-assessments, whereas people who are persistently unemployed may have a perspective on the challenges associated with employment.

In our research,⁹ high-contact clinicians (ie, case manager, psychiatrist, therapist, or residential facility manager) were bet­ter able than family or friends to generate ratings from an assessment questionnaire that correlated with performance-based measures of patients’ ability to perform everyday functional skills. The ratings were generated across multiple functional status scales, suggesting that the rater was more important than the specific scale. We concluded that high-contact clinicians can generate ratings of everyday functioning that are convergent with patients’ abilities, even when they have no information about actual performance scores.

Cognitive performance. When self-reported cognitive abilities are correlated with the results of performance on neuro­psychological assessments, the results are quite consistent. Patients provide reports that do not correlate with their objective performance.¹¹ Interestingly, when clini­cians were asked to use the same strategies as patients to generate ratings of cognitive impairment, clinician ratings had consider­ably greater evidence of validity. In several studies, patients’ ratings of their cognitive performance did not correlate with their neuropsychological test performance, even though they had just been tested on the assessment battery. Ratings by clinicians or other high-contact informants (who were unaware of patients’ test performance) were much more strongly related to patients’ objective test performance, compared with patient self-reports.¹²

The convergence of clinician ratings of cognitive performance with objective test data has been impressive. Correlation coef­ficients of at least r = 0.5, reflecting a moder­ate to large relationships between clinician ratings and objective performance, have been detected. Individual cognitive test domains, such as working memory and processing speed, often do not correlate with each other or with aspects of everyday functioning to that extent.¹³ These data sug­gest that a clinician assessment of cognitive performance, when focused on the correct aspects of cognitive functioning, can be a highly useful proxy for extensive neuropsy­chological testing.

Social cognitive performance. Introspective accuracy for social cognitive judg­ments can be assessed similarly to the strategies used to assess the domains of everyday functioning and cognitive perfor­mance. Patients are asked to complete a typi­cal social cognitive task, such as determining emotions from facial stimuli or examin­ing the eye region of the face, to determine the mental state of the depicted person. Immediately after responding to each stimu­lus, participants rate their confidence in the correctness of that response.

Consistent with the pattern of introspec­tive accuracy for everyday functioning, patients with schizophrenia tend to make more high-confidence errors than healthy individuals on social cognitive tasks. That is, the patients are less likely to realize when they are wrong in their judgments of social stimuli. A similar pattern has been found for mental state attribution,¹⁴ rec­ognition of facial emotion from the self,¹⁵ and recognition of facial emotion from others.¹⁶ These high-confidence errors also are more likely to occur for more difficult stimuli, such as faces that display only mildly emotional expressions. These dif­ficulties appear to be specific to judgments in an immediate evaluation situation. When asked to determine if the behavior of another individual is socially appropri­ate, individuals with schizophrenia are as able as healthy individuals to recognize social mistakes.¹⁷ This work suggests that, at least within the domain of social cogni­tion, introspective accuracy impairment is not caused by generalized poor judgment, just as self-assessments of disability and illness burden are generated at random.

Choosing a reliable informant
If a clinician has not had adequate time or exposure to a patient to make a cogni­tive or functional judgment, what should the strategy be? If asking the patient is uninformative, who should be asked? Our group has gathered information that may help clinicians identify informants who can provide ratings of cognitive perfor­mance and everyday functioning that are convergent with objective evidence.

In a systematic study of validity of reports of various informants, we com­pared correlations between reports of competence of everyday functioning with objective measures of cognitive test per­formance and ability to perform everyday functional skills. Our findings:
   • Patient reports of everyday function­ing were not correlated with performance-based measures for any of 6 rating scales.⁹
   • Clinician reports of everyday func­tioning were correlated with objective per­formance across 4 of 6 rating scales.
   • Correlations between ratings gener­ated by friend or relative informants and other information were almost shocking in their lack of validity (Table 2).⁹