Elsevier

Psychiatry Research

Volume 104, Issue 2, 1 November 2001, Pages 145-156
Psychiatry Research

Problem-solving abilities in unipolar depressed patients: comparison of performance on the modified version of the Wisconsin and the California sorting tests

https://doi.org/10.1016/S0165-1781(01)00307-9Get rights and content

Abstract

Problem solving relies on such abilities as decision-making, planning, initiation and hypothesis testing. Although problem-solving deficits have been consistently reported in depression, the specific nature of these deficits is not fully elucidated. In order to assess and isolate cognitive processes underlying problem-solving impairments in depression, depressed patients and normal controls were evaluated with the modified version of the Wisconsin Card Sorting Test (WCST) and the California Card Sorting Test (CCST). The California Card Sorting Test, unlike the modified WCST, provides several different measures of concept generation, concept identification and concept execution. Compared with controls, depressed patients did not show any deficits on all the measures of the modified WCST. In contrast, depressed patients evidenced mild impairment on the CCST with a specific deficit on concept generation but no major problems in concept identification and concept execution. The deficit in concept generation may be rooted in multiple factors such as hypothesis-testing deficits, a loss of cognitive flexibility and a conservative style of response. Since a positive relation between problem-solving deficits and the mean duration of the depressive episode was observed, problem-solving abilities might be predictive of poorer outcome in patients with unipolar affective disorders.

Introduction

Executive functioning includes cognitive processes such as inhibition, planning, dealing with novelty, selecting strategies and monitoring performance. This set of cognitive functions controls and integrates other cognitive processes such as memory or verbal abilities (Rabbit, 1997). Several neuropsychological studies have demonstrated impairment on executive tests in young and older depressed patients (Beats et al., 1996, Cassens et al., 1990, Franke et al., 1993, Palmer et al., 1996; for a review, see Elliott, 1998). Among these neuropsychological tasks, tests targeting grouping and sorting functions are frequently used to examine the regulatory processes associated with problem-solving capacity.

Evidence of problem-solving impairments has been shown in depressed patients (Channon and Baker, 1996, Silberman et al., 1983). The Wisconsin Card Sorting test (WCST) is one of the most widely used tests in clinical neuropsychological practice to assess problem-solving capacity. By requiring subjects to sort cards according to criteria that must be inferred from feedback from the examiner, the WSCT evaluates both the ability to identify abstract categories and behavioral flexibility (Milner, 1963, Malloy and Richardson, 1994). Although there are some divergent results (Martin et al., 1991), many studies have reported that depressed patients perform poorly on the WCST (Austin et al., 1992, Axelrod et al., 1994, Merriam et al., 1999). Usually, patients with depression complete fewer categories compared with controls and show high rates of perseverative and non-perseverative errors (Channon, 1996). Nelson (1976) modified the WCST by reducing the combination of response cards and removing ambiguous cards that shared more than one attribute with stimulus cards. These changes allowed the subject's sorting strategy to be more easily inferred and allowed the examiner to provide unambiguous feedback to the subject. In addition, the rules of the Modified Card Sorting Test (MCST) allow patients to choose the order in which the cards are sorted whereas the WCST requires that cards be sorted in a fixed order. Moreover, on the MCST, the examiner asks patients to change the rule after six consecutively corrected sorts. These modifications increase the degree of flexibility inherent in the test (De Zubiracay and Ashton, 1996). Because the MCST is a less stressful task, it may be especially useful for evaluating problem-solving abilities in depressed patients (Albus et al., 1996, Simpson et al., 1998). One limitation of the WCST and the MCST is that many sources of performance failure on these tasks have been identified, i.e. evaluating too many rules or hypotheses, neglecting the reward signal or failing to alter behavior in response to feedback (Dehaene and Changeux, 1991) and one cannot easily infer from the test the exact nature of the subject's impairments in problem solving (Levine et al., 1995).

Delis et al. (1992) designed a new sorting task, the California Card Sorting Test (CCST), to isolate and assess the multiple cognitive processes underlying problem-solving abilities. The CCST provides assessment of concept generation, concept identification and concept execution by asking subjects to sort three sets of six cards in three different sorting conditions (free, structured and cued). The CCST also provides measures of a subject's ability to explain the sorting. Several studies confirm the sensitivity of the CCST to evaluate problem solving in patients with Parkinson's disease (Beatty and Monson, 1990, Dimitrov et al., 1999), multiple sclerosis (Beatty and Monson, 1996), schizophrenia (Beatty et al., 1994) and chronic alcoholism (Beatty et al., 1993). In a recent study (Fossati et al., 1999), we evaluated unipolar depressed patients, patients with schizophrenia and normal controls with several executive tasks, including the CCST and the MCST. Patients with depression showed deficits on the CCST with normal performance on the MCST (Fossati et al., 1999).

The aim of the present study was: (1) to replicate these previous findings on the CCST and the MCST with a new sample of unipolar depressed patients; and (2) to focus on problem-solving abilities in depression in order to isolate cognitive processes underlying problem-solving impairment in depressed patients.

In line with results of our previous study (Fossati et al., 1999), we hypothesized that patients with depression would mainly show deficits on the CCST with difficulties in generating concepts and shifting attention across concepts.

Section snippets

Subjects

Patients were recruited from the Department of Psychiatry at the Pitié-Salpétrière Hospital. Twenty-two patients, ranging in age from 19 to 55 years, acutely ill at the time of testing and admitted for a major depressive episode without psychotic features, gave their consent to participate in this study. These patients were not included in the previously published study. Two psychiatrists made diagnoses using a checklist encompassing DSM-IV criteria for major depression and after a

Modified version of the WCST (Nelson, 1976)

Table 2 summarizes results on the MCST and digit-span tests. Depressed patients made more perseverative errors than control subjects; however, the MANOVA using the main scores of the MCST (the number of categories, the percentage of conceptual response, the number of total errors and the number of perseverative errors; see Table 2) did not show a significant difference between depressed patients and controls [F(4,39)=2.07; ns], suggesting that depressed patients did not exhibit significant

Discussion

The present study examined problem-solving abilities in depressed patients and normal controls using two different card-sorting tasks. Compared with controls, patients exhibited mild problem-solving deficits on the California Card Sorting Test, but no impairments on the Modified Version of the Wisconsin Card Sorting Test. These results confirm our preliminary findings (Fossati et al., 1999) in a new sample of unipolar depressed patients.

References (47)

  • M.P. Austin et al.

    Cognitive function in major depression

    Journal of Affective Disorders

    (1992)
  • G.S. Alexopoulos et al.

    Executive dysfunction and long-term outcomes of geriatric depression

    Archives of General Psychiatry

    (2000)
  • B. Axelrod et al.

    Poor differential performance on the Wisconsin Card Sorting Test in schizophrenia, mood disorder and traumatic brain injury

    Neuropsychiatry, Neuropsychology and Behavioral Neurology

    (1994)
  • B.C. Beats et al.

    Cognitive performance in tests sensitive to frontal lobe dysfunction in the elderly depressed

    Psychological Medicine

    (1996)
  • W.W. Beatty et al.

    Problem solving by schizophrenic and schizoaffective patients on the Wisconsin and California Sorting Tests

    Neuropsychology

    (1994)
  • W.W. Beatty et al.

    Problem solving deficits in alcoholics: evidence from the California Card Sorting Test

    Journal of Studies on Alcohol

    (1993)
  • W.W. Beatty et al.

    Problem solving in Parkinson's disease: comparison of performance on the Wisconsin and California Sorting Tests

    Journal of Geriatric Psychiatry and Neurology

    (1990)
  • W.W. Beatty et al.

    Problem solving by patients with multiple sclerosis: comparison of performance on the Wisconsin and California Sorting Tests

    Journal of the International Neuropsychological Society

    (1996)
  • A.T. Beck

    Cognitive Therapy and the Emotional Disorders

    (1976)
  • P.W. Burgess

    Theory and methodology in executive function research

  • D.B. Burt et al.

    Depression and memory impairment: a meta-analysis of the association, its pattern and specificity

    Psychological Bulletin

    (1995)
  • G. Cassens et al.

    The neuropsychology of depression

    Journal of Neuropsychiatry and Clinical Neurosciences

    (1990)
  • S. Channon et al.

    Depression and problem solving performance on a fault diagnosis talk

    Applied Cognitive Psychology

    (1996)
  • Cited by (51)

    • Predictors of neurocognitive impairment at 2 years after a first-episode major depressive disorder

      2016, Comprehensive Psychiatry
      Citation Excerpt :

      Previous study has defined executive function as “complex cognitive processing requiring the co-ordination of several sub processes to achieve a particular goal” [59]. Most studies have consistently reported that executive function is consisted of multiple components, including set-shifting, inhibition, working memory, fluency [60], planning and problem solving [61]. More specifically, numerous studies have indicated cognitive impairments in the multiple aspects of executive function [15].

    • Are occupational factors and mental difficulty associated with occupational injury?

      2011, Journal of Occupational and Environmental Medicine
      Citation Excerpt :

      Indeed, certain depressive symptoms such as sleep disorders and tiredness may impact on both physical and mental capacities. Major depression is associated with executive dysfunctions, altered memory, and reduced problem-solving ability10,43 through aberrant recruitment of brain resources10 and the impairment of basic executive processes, such as information updating, set shifting, or cognitive control.44 Individuals with a poor person–environment fit or who are more sensitive to the work environment are subject to an increased job stress and therefore to increased injury risk.4,7,45

    View all citing articles on Scopus
    View full text