Background
Neuropsychological deficits have been reported in psychosis since Kraepelin [
1] and are still of high interest [
2]. A meta-analysis of patients with psychotic disorders showed deficits in all cognitive areas, especially in the domains of verbal memory and processing speed [
3]. It was also observed that executive functions are impaired in psychotic patients [
4]. Deficits in executive function, attentional performance and memory are also described for patients with bipolar disorders [
5] and for patients with depressive disorders [
6,
7]. Comparing the cognitive performance of patients with psychosis and affective disorders, no differences were found [
8‐
11]. This is in contrast to the results of Bonner-Jackson et al. [
12]. The authors had examined 244 patients diagnosed with schizophrenia, other psychosis or non-psychotic depression over a period of 20 years after index treatment. At all seven points of measurement, the cognitive performance of patients with schizophrenia was significantly worse than patients with other disorders. Again, deficits in processing speed were the most common. Inconsistent findings were reported on the stability of the described deficits over the course of relatively brief inpatient treatment, with some reports of no improvement in cognitive deficits between admission and discharge [
9,
13], and other reports of demonstrated improvements [
10].
Cognitive deficits have considerable prognostic impact [
14,
15]. It is widely accepted that the correlation between cognitive impairment and psychosocial functional level or occupational activity is significantly stronger than between clinical symptoms and functional level or occupational activity [
14,
15]. The cognitive functional level proved to be a good predictor for the number and quality of social relationships [
16]. Tourjman et al. [
17] showed for depressed patients that the results of a cognitive screening were associated with severity of illness, self-reported cognitive dysfunction and impairment in daily life. Consequently, the assessment of cognitive performance is relevant for therapy and rehabilitation planning, but also for providing realistic job and employment perspectives [
18‐
20].
Screening instruments are economical and easy to apply in everyday clinical practice. Several screening methods are available for the detection of cognitive disturbances in mental disorders. The Screen for Cognitive Impairment in Psychiatry (SCIP, [
21]) and the Brief Assessment of Cognition in Schizophrenia (BACS, [
22]) were designed for use in psychiatric samples. The SCIP requiring slightly less administration time compared to the BACS and it appears to have greater sensitivity to cognitive deficits associated with psychosis [
2] compared to the established Montreal Cognitive Assessment (MoCA, [
23]).
Several international studies have offered support for the utility of the SCIP as a screening tool in psychiatry applying the SCIP are already available [
2,
8,
17,
24‐
26]. The primary emphasis of the prior reports concerned the psychometric properties of the SCIP in samples that ranged in size from
n = 40 [
17] to a high
n = 514 [
8]. Our goal was to extend these results by examination of the utility of integrating the SCIP into the routine clinical assessments undertaken on admission and discharge within a more typical high volume inpatient environment. To this end, the SCIP was added to the routine evaluations undertaken within two general psychiatric wards in 2012. Since that time we have administered the SCIP to
n = 529 patients on admission. The aim of this study was to examine and compare the cognitive profiles of a diverse group of acute psychiatric inpatients at admission, and to assess any changes in profile that may occur between admission and discharge. Both absolute and normalized test values of performance were analyzed. Furthermore, we examined whether different clusters could be found based on the cognitive performance profiles.
Discussion
The SCIP is an economical, internationally approved and validated screening tool to assess cognitive performance in psychiatric patients. In this report we provide data of a naturalistic sample of 529 psychiatric inpatients screened with the SCIP at the time of admission to a general psychiatric ward. This is the first paper to report data of such a sample. Results for the SCIP total score and the five subscale scores corresponded to published data from other translations of the SCIP (e.g. [
2]). Diagnosis-specific differences between psychotic and affective disorders in our sample did not occur. Our results are therefore consistent with the results of Gómez-Benito et al. [
8], Sachs et al. [
11], Neu et al. [
10] and Hill et al. [
9]. In addition to the absolute values, we used the results of the healthy population norms from Murri et al. [
2] to investigate the proportion of our sample with pathological results. This revealed a high percentage of cognitive dysfunction in our sample evident in the SCIP total score (over 70%) as well as for the three subtests with significant demands for attention and processing components (working memory, verbal fluency test, psychomotor speed test). The subtests of verbal learning and memory on the other hand were pathological in less than 40% of the patients.
Looking at the cognitive performance profiles over the course of inpatient treatment, there were significant improvements from admission to discharge in the total score and the subtests for verbal fluency, processing speed and working memory. In contrast, verbal learning, both immediate and delayed, showed no changes over time. This is in contrast to previous findings with reported deficits as well as in the domains of verbal memory and processing speed [
3,
4]. In terms of the normalized values, large effect sizes were observed for the improvement in the SCIP total score and the psychomotor speed test between admission and discharge. Taken together, most cognitive improvements occurred in working memory, processing speed and verbal fluency (which also includes a speed factor). We suppose that social psychiatric inpatient treatment improves most in cognitive domains of attention, working memory and speed components, because in daily ward living, social interaction and communication are key processes within the recovery model. Possible effects of the reapplied psychiatric medication during an inpatient stay must also be taken into account. On the one hand, improvements in cognitive performance are conceivable, particularly if second generation antipsychotics are given [
36,
37] on the other hand, side effects such as fatigue and loss of attention could also occur [
10]. In the present study, the influence of medication effects could not be analyzed.
Following Rodriguez et al. [
38] we further investigated whether different patient clusters could be identified based on the results of a screening tool. In our analysis, two clusters were extracted based on SCIP results at admission. Rodriguez et al. [
38] extracted three clusters corresponding to a general impairment group, an attention, speed and verbal deficit group, and a third cluster with above average attention but impaired verbal memory. In contrast to Rodriguez et al. [
38], the sample reported here separated into either one group with mild impairment in terms of mean value with almost 50% of pathological results on the SCIP (cluster 2) and 1 sec group with severe impairment in terms of mean with 100% of pathological results on the SCIP (cluster 1). Patients of cluster 1 were older, had more comorbid diagnoses and had more previous admissions. However, compared to cluster 2, they improved significantly more between admission and discharge results, both in the overall score and in the verbal learning test. Since the patients of cluster 2 are already considerably less impaired in the admission findings based on the values of Murri et al. [
2], a ceiling effect must be considered for this cluster. In conclusion, cluster 1 could be interpreted as a sample of chronic patients, more impaired clinically as well as cognitively, who then benefitted from the social psychiatric inpatient stay.
Our study has several limitations. First, our results are based on routinely collected clinical data by a screening tool for cognitive performance. Beside the ecological validity advantages of such a naturalistic clinical dataset, selection processes of the examined patients must be discussed. Only those, who were willing to participate in such a diagnostic procedure, could be included. To investigate possible selection processes concerning repeated measurement, drop-out analyses were performed. Compared to the complete cases with both admission and discharge data, the patients that dropped out prior to the discharge evaluation differed only in sociodemographic variables, and a shorter length of stay. It can therefore be assumed that selection was based more on organizational concerns and less on disease severity. Furthermore it must be noted that patients with cognitive impairment due to other disorders are regularly not treated on the units where the patients were recruited but presence of such conditions in a milder degree had not been predefined as an exclusion criterion. Comorbid disorders should be considered more in future work.
Another limiting factor is the lack of a concurrent healthy control sample for comparison, and the absence of published data with reported SCIP scores from a German translation of the SCIP. We selected the relatively large sample reported by Murri et al. [
2] from the Italian translation over similar reports from the Spanish translation [
25,
26]. When comparing with the healthy sample of Murri et al. [
2], the differences in age, gender distribution and educational status compared to our sample must be mentioned as a limitation. With the current demonstration of the sensitivity of the German translation of the SCIP to the cognitive limitations apparent in an inpatient psychiatric sample we are confident that the time and effort required to secure normative data for this version would be very well spent. As in all investigations of cognitive limitations, we were not able to include in our analysis many additional factors that could influence or potentially mediate test results, e.g. medication or learning effects. Moritz et al. [
39] were able to show that factors such as motivation and attitude towards testing or medication significantly reduce cognitive abnormalities in schizophrenia sufferers. This all should be considered in future work.
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