The results of Wisconsin Card Sorting Test in patients under forensic observation of their mental states in violent and non-violent subgroups

TL;DR

This study compared the Wisconsin Card Sorting Test results of forensic psychiatric patients to normative data and found significant differences, but no differences between violent and non-violent subgroups.

Contribution

The study provides new empirical data on executive function differences in forensic psychiatric patients compared to norms, but found no subgroup differences in violence.

Findings

Forensic psychiatric patients showed significant deviations in WCST parameters compared to normative data.

No significant differences were found between violent and non-violent subgroups in WCST performance deviations.

The study's limitations include a small and heterogeneous sample.

Abstract

Previous studies showed, that reduced executive function can be associated with antisocial and aggressive behavior. For the measurement of executive functions numerous standardized neuropsychological tests are available.

We thought to compare the results of an executive function examination with Wisconsin Card Sorting Test (WCST) of patients observed at the Semmelweis University’s Department of Psychiatry and Psychotherapy to normative data from published database. We also performed a subgroup analysis between the violent and non-violent groups of the patients.

After data clearance our dataset consisted of 20 patients, who were divided into two groups based on whether the crime they committed before their admission was violent according to the Cornell scale.The analyzed parameters were the number of perseverative errors, the percentage of perseverative errors, and the number of completed categories. For comparison, the data bank from the 1993 edition of the WCST manual as normative data was used. The deviation from the healthy average for all three parameters was compared between the violent and non-violent groups using a two-sample T-test.

There was significant difference between the patient and normal populations in all the 3 analyzed WCST parameters: the mean difference was 9,37+2,764, (p=0,0008) in the number of perseverative errors, 14,04+2,21 (p<0,0001) in the percentage of perseverative errors and -2,39+0,34 (p<0,0001) in the number of completed categories (Table 1).
Table 1:The difference between the average scores of healthy individuals grouped by age (from the 1993 WCST manual) and the scores of the patients.
Observed parameter
Average difference(Patient-normal)
SD
Confidence interval (95%)P valuenumber of completed categories-2,390,343-3,064 ─ 1,716<0,0001number of perseverative errors9,372,7643,936 ─ 14,8040,0008percentage of perseverative errors14,042,2129,692─18,388<0,0001

The difference between the average scores of healthy individuals grouped by age (from the 1993 WCST manual) and the scores of the patients.

On the other hand, there were no significant differences between the violent and non-violent subgroups in the average deviations (from the normative data) of the number of perseverative errors, the percentage of perseverative errors and the number of completed categories (with p-values of 0.092, 0.34 and 0.59, respectively).

As a limitation, it is important to note that due to the low sample size, and our sample’s heterogeneity in terms of psychiatric diagnosis, drawing reliable conclusions is not possible. However, our results were in line with previous similar research in the forensic psychiatric population (though not under forensic mental state observation) regarding the significant deviations in two examined WCST parameters when compared to normative data. Additionally our study did not find significant difference between the violent and non-violent subgroups of the patients.

None Declared

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