|Year : 2015 | Volume
| Issue : 1 | Page : 54-59
Cognitive impairment in depressed students of Cairo University Hospital
Zeinab Sarhan, Heba Fathy, Nagwan Madbouly
Department of Psychiatry, Faculty of Medicine, Cairo University, Cairo, Egypt
|Date of Web Publication||23-Mar-2015|
Department of Psychiatry, Faculty of Medicine, Cairo University, Cairo
Source of Support: None, Conflict of Interest: None
Major depression may affect the ability to think, concentrate, make decisions, formulate ideas, reason, and remember. Patients with major depression also often show neurocognitive deficits consistent with frontal lobe dysfunction. The co-occurrence of depressive symptoms and cognitive impairment plays a role in determining disability in individuals.
Aim of the study
To assess the presence of cognitive deficits in depressed undergraduate university students and then to assess the correlation between severity of depression and cognitive impairment in these students.
Patients and methods
After obtaining consent from the ethical committee in Kasr El Aini Hospital, 50 patients with the diagnosis of Major Depressive Disorder according to the DSM-IV criteria were recruited from the psychiatric outpatient clinic of Cairo University Student Hospital, with no sex preference. Fifty control participants of similar age, sex, and educational backgrounds were recruited as volunteers. Psychometric procedures: Beck Depression Inventory for severity of depression, selected subtests of Wechsler Adult Intelligence Scale (WAIS), and Wechsler Memory Scale-Revised (WMS-R).
Medical and paramedical students recruited from six faculties constituted 40% of the entire sample. Forty percent of the cases were diagnosed with moderate depression, whereas 60% of them were diagnosed with severe depression. All the scores of the subtests of WAIS and WMS-R used were higher in the control group. The scores of the Beck Depression Inventory were correlated positively with the digit symbol and digit span subtests of WAIS and to figural memory and visual memory span subtests of WMS-R.
Depressed undergraduate university students had more cognitive deficits than nondepressed students. The severity of depression was correlated positively with some of these cognitive deficits.
Keywords: cognitive deficits, major depression, undergraduate university students
|How to cite this article:|
Sarhan Z, Fathy H, Madbouly N. Cognitive impairment in depressed students of Cairo University Hospital. Egypt J Psychiatr 2015;36:54-9
|How to cite this URL:|
Sarhan Z, Fathy H, Madbouly N. Cognitive impairment in depressed students of Cairo University Hospital. Egypt J Psychiatr [serial online] 2015 [cited 2021 Jan 21];36:54-9. Available from: http://new.ejpsy.eg.net/text.asp?2015/36/1/54/153780
| Introduction|| |
Major depression may affect the ability to think, concentrate, make decision, formulate ideas, reason, and remember (Marazziti et al., 2010).
Emerging literature suggests that depressive symptoms and cognitive impairment play a role in determining disability in individuals (Rieder, 2001). Patients with major depression also often show neurocognitive deficits consistent with frontal lobe dysfunction (Rogers et al., 2004). These findings support a solid theory of depression, which suggests that hypofunction of the dorsolateral prefrontal cortex and related prefrontal regions accounts for the cognitive symptoms of depression with attention, concentration, and memory (Mayberg et al., 2005).
Depressed patients show particular difficulties with memory tasks requiring sustained effort, such as list learning and free recall, which are qualitatively different from tasks carried out automatically (e.g. memory for spatial events). However, some authors believe that memory deficits seem to be independent of the patients' current mood state (McEwen and Magarinos, 2002).
Performance on measures of executive functioning tends to be impaired in depressed patients of different ages (Stordal, et al., 2004). Several studies have reported that young depressed patients show deficits in some components of executive functioning, such as attention, short-term and working memory, and in psychomotor skills, whereas data on verbal memory and learning functions are controversial (Castaneda et al., 2008).
Although depression is associated with a high degree of cognitive impairment, academic disability, and reduced functional performance, this relationship is poorly understood.
This study aimed to examine the objectively measured cognitive impairment in a chosen group of undergraduate students who had a diagnosis of depression according to the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria of the American Psychiatric Association.
| Aim of the study|| |
The aim of this study is to assess the presence of cognitive deficits in depressed undergraduate university students and then to assess the correlation between severity of depression and cognitive impairment in these students.
| Participants and methods|| |
After obtaining approval from the Scientific and Ethical Committee in Kasr El Aini hospital, 50 patients (age: 18-25 years) with the diagnosis of major depressive disorder diagnosed according to the DSM-IV criteria were recruited from the psychiatric outpatient clinic of Cairo University Student Hospital, with no sex preference. Fifty control participants of similar age, sex, and educational backgrounds were recruited as volunteers. All the scales showed the absence of psychopathology in the control group. There was no specific preference in the selection of faculty students. All the hundred students were recruited from 19 faculties. They were all drug-naive, that is, with no history of intake of any medications in the previous 6 months. We excluded patients with comorbid psychotic or anxiety symptoms, personality disorder, organic/neurological brain diseases, or a history of substance abuse. All participants provided consent to participate in the study after a full explanation of the procedures was provided.
A specially designed semistructured interview derived from the Kasr El Aini psychiatric sheet was used to cover demographic data, personal data, history, and family history.
Structured clinical interview for DSM-IV Axis I disorders (First et al., 1996)
It is a semistructured interview used to make major DSM-IV Axis I diagnoses. It was administered by a clinician or a trained mental health professional who was familiar with the DSM-IV classification and diagnostic criteria (American psychiatric association, 1994).
BDI (Arabic version) (Ghareeb, 2000)
It is a self-report scale designed to assess DSM-IV defined symptoms of depression such as sadness, guilt, loss of interest, social withdrawal, increase and decrease in appetite or sleep, suicidal ideation, and other behavioral manifestations of depression over the previous 2 weeks. It can also be used over time to monitor symptoms and to assess response to therapeutic interventions. The inventory is composed of 21 groups of statements on a four-point scale with the patient selecting the one that best matches his or her current state. Each statement group corresponds to a specific behavioral manifestation; responses are scored 0-3, corresponding to no, mild, moderate, or severe depressive symptoms. The score range varies from 0 to 63, where a higher score indicates greater severity of depression. Scores in the range of 0-13 indicate no or minimal depression; scores in the range of 14-19 indicate mild depression; scores in the range of 20-28 indicate moderate depression; and scores in the range of (29-63) indicate severe depression. It has been translated into Arabic by Gharib abdel Fattah and has been used in many studies.
WAIS (Arabic edition) (Melika, 1996)
This well-known and standardized intelligence test is used to assess intellectual abilities of adults, as well as provide scores on a variety of cognitive tasks covering a range of skills. In this study, we chose two of the verbal subtests [digit span for auditory verbal short-term (working) memory and similarities for verbal concept-formation] and two of the performance subtests (digit symbol to assess problem-solving abilities, indicative of executive function, and block design to assess visuoconstructive abilities and nonverbal concept formation).
WMS-R (Wechsler, 1996)
It is an individually administered, clinical instrument used to assess major dimensions of memory functions. In this work, we selected the subtests that assess visual memory. They included four subtests: figural memory, visual paired association, delayed visual reproduction, and visual memory span.
Data were statistically described in terms of range, mean± SD, frequencies (number of cases), and percentages when appropriate. Comparison of quantitative variables between the study groups was carried out using the Student t-test for independent samples to compare two groups when normally distributed and the Mann-Whitney U-test for independent samples when not normally distributed. Comparison of quantitative variables between more than two groups of normally distributed data was carried out using the one-way analysis of variance test with post-hoc multiple two-group comparisons whereas non-normal data were compared using the Kruskal-Wallis analysis of variance test with the Mann-Whitney U-test for independent samples for post-hoc multiple two-group comparisons. For comparison of categorical data, the χ2 -test was performed. The exact test was used when the expected frequency is less than 5. The correlation between various variables was assessed using the Spearman rank correlation equation for non-normal data. A P value less than 0.05 was considered statistically significant. All statistical calculations were carried out using computer programs Microsoft Excel 2007 (Microsoft Corporation, New York, USA) and statistical package for the social science (SPSS Inc., Chicago, Illinois, USA) version 15 for Microsoft Windows.
| Results|| |
The mean age of both the case and the control groups was ~19 years. There was no statistically significant difference between both groups in the sex distribution. Hundred students were recruited from 19 faculties, students from the Faculty of Medicine represented 25% of the sample.
According to Beck Depression Inventory (BDI), 20 patients (40% of the sample) were diagnosed with moderate depression whereas 30 patients (60% of the sample) were diagnosed with severe depression.
There was a statistically significant difference between the mean BDI scores in the case and the control groups. The mean score of digit symbol in the control group was higher than the mean score in the case group, and this difference was statistically significant (P = 0.02). Although the scores of the remaining subtests of Wechsler adult intelligence scale (WAIS) and all the Wechsler Memory Scale-Revised (WMS-R) subtests were higher in the control group, none of these results was statistically significant.
The mean scores of the subtests of both the WAIS and the WMS-R were higher in the moderate depression group than the severe depression group, but none of these results were statistically significant ([Table 1] [Table 2] [Table 3] [Table 4] [Table 5]).
|Table 3 Comparison of mean ± SD of BDI, WAIS, and WMS-R in cases and controls|
Click here to view
| Discussion|| |
This study attempted to assess the presence of cognitive deficits in patients with MDD who presented to the psychiatry clinic in the student hospital Cairo University and to establish the relation between the severity of depression and cognitive impairment.
The mean scores of all the subtests of WAIS and WMS-R were higher in the control group than in the case group, but these results did not reach statistical significance, except for scores of the digit symbol subtest of WAIS.
In the case group, the scores of the BDI ranged between 27 and 55, with a mean score of 36.5 ± 8.084, whereas the BDI results in the control group ranged between 5 and 13, with a mean score of 10.06 ± 2.142.
Twenty patients, representing 40% of the case group, were diagnosed with moderate depression and thirty patients, representing 60% of the sample, were diagnosed with severe depression. No participant was diagnosed with mild depression. This was not in agreement with the work of Al Faris et al. (2008), who found the highest prevalence of depressive symptoms in mild cases (42%), whereas there were 17% moderate cases and 11% severe cases.
Medical and paramedical students recruited from six faculties (medicine, nursing, dentistry, pharmacology, physiotherapy, and veterinary) constituted forty percent of the sample group (46% of the case group and 34% of the control group). This was similar to a study by Al Faris et al. (2008), who found that Saudi medical students have a higher rate of depressive symptoms than the general population and age-matched and sex-matched peers. The presence and severity of depressive symptoms showed a statistically significant association with early academic years. This was also consistent with the work of Elzubeir et al. (2010), who found that Arab medical students were at a higher risk of developing depression than the general population, and that risk increased steadily between the years 1998 and 2009. The high prevalence of depressive symptoms is an alarming sign and calls for remedial action, particularly for the junior and female students (Baldassin et al., 2008).
The similarities subtest is one of the three subtests that measure the verbal comprehension index and verbal IQ. It measures abstract verbal reasoning. The mean score of similarities in the control group was higher than the mean score in the case group, although it did not reach statistical significance. This was consistent with the result of a study carried out by the University of Exeter, England that found that 121 patients with depression had difficulties with abstract thinking problem solving and processing speed (Watkins et al., 2011).
The digit span subtest is one of the working memory indexes, followed by verbal IQ. It measures attention, concentration, and mental control. The mean score of digit span in the control group was higher than the mean score in the case group, but this did not reach statistical significance. This was consistent with the work of Haris et al. (2006), who found that 129 patients had achieved lower scores on the digit span subtest than normal individuals.
The block design subtest is one of the three perceptual organization indexes, followed by performance IQ. It measures spatial perception, visual abstract processing, and problem solving. The mean score of block design in the control group was higher than the mean score in the case group, but this was not significant. This was consistent with the work of Griffiths et al. (2011), who found that 66 (23 males and 43 females) out of 303 college students completed the block design test with poor scores because of depressive symptoms.
The digit symbol subtest is one of the two processing speed indexes, followed by performance IQ. It measures visual-motor coordination, motor and mental speed, visual working memory, visual perception analysis, and scanning speed. The mean score of digit symbol in the control group was higher than the mean score in the case group, and these results reached statistical significance. This was consistent with the work of Van Hoof et al. (1998), who found that the digit symbol subtest was very useful in elaboration of mental slowing in depression.
The figural memory subtest was used to test visual memory by showing the participant abstract designs. The mean score was higher in the control group than the case group, although this was not significant. This was consistent with the work of Brandes et al. (2002), who found cognitive impairment in patients with depression is remarkably high in comparison with normal individuals.
The mean score of the visual paired association subtest was higher in the control group than the case group, although this was not significant. This was consistent with the work of Majer et al. (2004), who found that all the 68 patients showed poor scores in all cognitive test, except the Stroop test and digit span.
The mean score of the delayed visual reproduction subtest was higher in the control group than the case group, although this was not significant. This was consistent with the work of Kalska et al. (2013), who found that 30 depressed patients were vulnerable to visual reproduction test while their scores on the verbal test were normal.
The mean score of the visual memory span subtest was higher in the control group than the case group, although this was not significant. This was consistent with the work of Westheide et al. (2007), who found that patients with remitted unipolar depression showed persistent visual memory loss.
None of the correlations between the scores of BDI and subtests of WAIS and WMS-R were statistically significant. These results are comparable with the results of a study by Maercker of University of Zurich that found a significant correlation between BDI scores and WAIS in both the pretreatment and the post treatment phase (Barbara et al., 2011), and comparable with the work of Farrin et al. (2003), who found that the depressed group scored significantly lower on the WMS-R subtests, especially the figural memory recall subtest.
The mean scores of the subtests of both the WAIS and the WMS-R were higher in the moderate depression group than the severe depression group, but none of these results were statistically significant; this is in agreement with Castaneda et al. (2008), who suggested that impairment in cognitive measures is not correlated to severity of depression (Papazacharios and Nardini, 2012).
| Conclusion|| |
Depressed undergraduate university students had more cognitive deficits than nondepressed students. The severity of depression was correlated positively with some of these cognitive deficits; however, this correlation was not statistically significant. Further studies with a larger sample would help to replicate these results. Future studies may integrate other factors into the course and management of major depressive disorder that may affect cognitive function, for example duration and number of the episodes and modality of treatment.
| Acknowledgements|| |
Conflicts of interest
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]