Verbal and visual learning ability in patients with treatment-resistant schizophrenia: A 1-year follow-up study

Urska Arnautovska; Kathryn Vitangcol; James P Kesby; Nicola Warren; Susan L Rossell; Erica Neill; Anthony Harris; Cherrie Galletly; David Castle; Dan Siskind

doi:10.1016/j.scog.2023.100283

Verbal and visual learning ability in patients with treatment-resistant schizophrenia: A 1-year follow-up study

Schizophr Res Cogn. 2023 Mar 28:33:100283. doi: 10.1016/j.scog.2023.100283. eCollection 2023 Sep.

Authors

Urska Arnautovska^{1

2}, Kathryn Vitangcol¹, James P Kesby^{3

4}, Nicola Warren^{1

2}, Susan L Rossell^{5

6}, Erica Neill⁵, Anthony Harris^{7

8}, Cherrie Galletly^{9

10}, David Castle^{6

11

12}, Dan Siskind^{1

2}

Affiliations

¹ Faculty of Medicine, University of Queensland, Brisbane, QLD 4102, Australia.
² Metro South Addictions and Mental Health Service, Woolloongabba, QLD 4102, Australia.
³ Queensland Centre for Mental Health Research, Wacol, QLD 4076, Australia.
⁴ Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4067, Australia.
⁵ Centre for Mental Health, School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC 5062, Australia.
⁶ Department of Psychiatry, St Vincent's Hospital Melbourne, Fitzroy, VIC 3065, Australia.
⁷ Specialty of Psychiatry, Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia.
⁸ Westmead Institute for Medical Research, Westmead, NSW 2145, Australia.
⁹ Discipline of Psychiatry, Adelaide Medical School, University of Adelaide, SA 5005, Australia.
¹⁰ Northern Adelaide Local Health Network, Adelaide, SA 5005, Australia.
¹¹ Centre for Complex Intervention, Centre for Addiction and Mental Health, Toronto 2283, Canada.
¹² Department of Psychiatry, The University of Toronto, Toronto 2283, Canada.

Abstract

Objective: In the general population, repeated cognitive testing produces learning effects with potential for improved test performance. It is currently unclear whether the same effect of repeated cognitive testing on cognition pertains to people living with schizophrenia, a condition often associated with significant cognitive impairments. This study aims to evaluate learning ability in people with schizophrenia and-considering the evidence that antipsychotic medication can additionally impair cognitive performance-explore the potential impact of anticholinergic burden on verbal and visual learning.

Method: The study included 86 patients with schizophrenia, treated with clozapine, who had persisting negative symptoms. They were assessed at baseline, weeks 8, 24 and 52 using Positive and Negative Syndrome Scale, Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-R (BVMT-R).

Results: There were no significant improvements in verbal or visual learning across all measurements. Neither the clozapine/norclozapine ratio nor anticholinergic cognitive burden significantly predicted participants' total learning. Premorbid IQ was significantly associated with verbal learning on the HVLT-R.

Conclusions: These findings advance our understanding of cognitive performance in people with schizophrenia and demonstrate limited learning performance in individuals with treatment-refractory schizophrenia.

Keywords: Anticholinergic burden, learning; Cognition; Practice effects; Psychosis; Treatment-resistant.