The Effects of Cognitive Remediation on Functional Outcomes Among People With Schizophrenia- a Randomized Controlled Study

Bhing Leet Tan (2011). The Effects of Cognitive Remediation on Functional Outcomes Among People With Schizophrenia- a Randomized Controlled Study PhD Thesis, School of Medicine, The University of Queensland.

       
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Author Bhing Leet Tan
Thesis Title The Effects of Cognitive Remediation on Functional Outcomes Among People With Schizophrenia- a Randomized Controlled Study
School, Centre or Institute School of Medicine
Institution The University of Queensland
Publication date 2011-10
Thesis type PhD Thesis
Supervisor Professor Robert King
Dr Geoffrey Waghorn
Total pages 421
Total colour pages 73
Total black and white pages 348
Language eng
Subjects 17 Psychology and Cognitive Sciences
1702 Cognitive Sciences
1199 Other Medical and Health Sciences
Abstract/Summary Background Cognitive impairment is a common feature among people with schizophrenia, as they typically perform between one and a half to two standard deviations below normal population (Bilder et al., 1995; Goldberg & Gold, 1995; Goldberg & Green, 2008). This has huge impact on aspects of daily life such as vocational functioning and community living skills. This is due to impairment in the ability to plan, organize and engage in functional tasks required in daily life. Cognitive remediation is an intervention to overcome the effects of cognitive difficulties through re-training and use of compensatory strategies. Although randomized studies have been conducted to show the positive effect of cognitive remediation on cognitive skills (McGurk, Twamley, Sitzer, McHugo, & Mueser, 2007; Twamley, Jeste, & Bellack, 2003; Wykes, Huddy, Cellard, McGurk, & Czobor, 2011), many of their control arms consist of intervention that are non-therapeutic in nature and are liable to allegiance effects. Hence, this study aimed to test if cognitive remediation will improve neurocognition and functioning of people with schizophrenia, using physical exercise as the control arm, as physical exercise has been shown to benefit people with psychiatric disorders (Richardson et al., 2005). Efforts were also made to minimize allegiance effects by appropriate blinding and training of therapists. This study will also shed light on the effectiveness of cognitive remediation in an English speaking Asian population. Methodology The Occupational Therapy Department at the Institute of Mental Health, Singapore, runs an outpatient day rehabilitation program as well as an outpatient vocational training program. Patients with DSM-IV diagnoses of schizophrenia or schizoaffective disorders were invited to participate in this study. Upon obtaining informed consent, participants were randomized to receive either Cognitive Remediation (CR) or Physical Exercise (PE) treatment. Cognitive Remediation consisted of: 1. Computer-assisted cognitive exercises for up to five hours each week for 12 weeks. 2. Cognitive-based counseling, based on application of cognitive strategies learned in cognitive exercises to their vocational training or day rehabilitation program. Physical exercise consisted of: 1. Physical exercise program for up to five hours each week for 12 weeks. 2. Physical exercise-based counseling, based on application of physical strategies learned during physical endurance exercise to their vocational training or day rehabilitation program. To minimize allegiance effects, both interventions had the same amount of treatment intensity and therapist-participant contact time. All therapists and participants were told that physical exercise was also a potentially beneficial intervention to be investigated for its effectiveness. In addition, this study was double blinded. Neuroognitive function and physical fitness were measured at baseline, upon completion of the program and at six month and one year follow-up. Among the day rehabilitation participants, their community abilities were also measured at the above intervals, while employment outcomes were charted among those in the vocational training program. The hypotheses of this study were: 1. Participants from the cognitive remediation group would show significantly more improvement in neurocognition than participants from the physical exercise group at the end of treatment and over the course of the one-year follow-up. 2. Participants who underwent cognitive remediation would achieve better overall functional outcomes, ie: longer employment hours or more improvement in Multnomah Community Ability Scale (MCAS scores) than participants in the physical exercise group. 3. Improved functional outcome would be associated with reduced symptom severity as measured by the Positive and Negative Syndrome Scale (PANSS). 4. There would be an association between improved functional outcomes and better quality of life among the participants. Results Results showed that cognitive remediation was able to produce significant differential improvement in all neurocognitive measures. Besides that, the cognitive remediation group achieved better attainment of vocational or independent living skills at post-intervention. Moreover, this group displayed better vocational and community ability outcomes at the end of one year follow-up. Repeated Measures analysis also showed better overall and negative symptoms improvement amongst the cognitive remediation group. In addition, improvements in certain neurocognitive functions predicted improvements in functional outcomes, symptoms and quality of life. Better functional outcomes were found to predict overall symptoms as well as negative symptoms recovery. On the other hand, negative symptoms were also shown to partially mediate the pathway between changes in neurocognition and changes in functional outcomes. However, improved functional outcome was not associated with better quality of life. Conclusion When compared against a credible intervention such as physical exercise, cognitive remediation was able to show significant positive effects on both neurocognition and functional outcomes among the Asian population of schizophrenia patients. References Bilder, R. M., Bogerts, B., Ashtari, M., Wu, H., Alvir, J. M., Jody, D., et al. (1995). Anterior Hippocampal Volume Reductions Predict Frontal Lobe Dysfunction In First Episode Schizophrenia Schizophrenia Research, 17(1), 47-58. Goldberg, T. E., & Gold, J. M. (1995). Neurocognitive Functioning in Patients with Schizophrenia: an Overview. In F. E. Bloom & D. J. Kufler (Eds.), Psychopharmacology: the Fourth Generation of Progress (pp. 1171-1183). New York: Raven Press. Goldberg, T. E., & Green, M. F. (2008). Neurocognitive Functioning in Patients With Schizophrenia: an Overview. In American College of Neuropsychopharmacology (Ed.), Neuropsychopharmacology-5th Generation of Progress. Brentwood: American College of Neuropsychopharmacology. McGurk, S. R., Twamley, E. W., Sitzer, D. I., McHugo, G. J., & Mueser, K. T. (2007). A Meta-Analysis of Cognitive Remediation in Schizophrenia. American Journal of Psychiatry, 164, 1791–1802. Richardson, C. R., Faulkner, G., Mcdevitt, J., Skrinar, G. S., Hutchinson, D. S., & Piette, J. D. (2005). Integrating Physical Activity Into Mental health Services for Persons With Serious Mental Illness. Psychiatric Services, 56(3), 324-331. Twamley, E. W., Jeste, D. V., & Bellack, A. S. (2003). A Review of Cognitive Training in Schizophrenia. Schizophrenia Bulletin, 29(2), 359-382. Wykes, T., Huddy, V., Cellard, C., McGurk, S. R., & Czobor, P. (2011). A Meta-Analysis of Cognitive Remediation for Schizophrenia: Methodology and Effect Sizes. American Journal of Psychiatry, 168(5), 472-485.
Keyword neurocognitive deficits
Cognitive Remediation
psychiatric rehabilitation
Functional Outcomes of Schizophrenia
Additional Notes Please print these pages in Colour 1, 156, 158, 159, 162, 164, 186, 187, 189, 190, 191, 192, 193, 194, 196. 197, 198, 202. 203, 204, 205, 207, 208, 209, 211, 212, 214, 215, 216, 217, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 249, 295, 300, 302, 306, 310, 319, 330, 338, 389, 390, 391, 392, 397, 398, 399, 400, 401, 402, 403, 404, 421 Please print these pages in Landscape and Colour: 68, 200, 201, 386, 405, 406, 407,

 
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Created: Fri, 01 Jun 2012, 14:15:52 EST by Bhing Leet Tan on behalf of Library - Information Access Service