Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis
Background: Sleep disturbances are associated with worse cognitive and psychotic symptoms in individuals with schizophrenia. Growing literature reveals sleep spindle deficits in schizophrenia may be an endophenotype reflecting a dysfunctional thalamo-thalamic reticular nucleus-cortical circuit. Sinc...
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| Format: | Article |
| Language: | English |
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Elsevier
2020-12-01
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| Series: | Sleep Medicine: X |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2590142720300148 |
| _version_ | 1818875768600526848 |
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| author | Chi Hung Au Christopher-James Harvey |
| author_facet | Chi Hung Au Christopher-James Harvey |
| author_sort | Chi Hung Au |
| collection | DOAJ |
| description | Background: Sleep disturbances are associated with worse cognitive and psychotic symptoms in individuals with schizophrenia. Growing literature reveals sleep spindle deficits in schizophrenia may be an endophenotype reflecting a dysfunctional thalamo-thalamic reticular nucleus-cortical circuit. Since thalamic functions link to cognitive, positive and negative symptoms, it is possible that sleep spindle activity is associated with these symptoms. The primary objectives of this systematic review were to assess the associations of sleep spindle activity in psychotic patients with 1) cognitive functions; and 2) positive and negative symptom severity. A secondary objective was to examine which spindle parameter would be the most consistent parameter correlating with cognitive functions, and positive and negative symptoms. Method: Observational studies reporting an association between sleep spindle activity and cognitive functions, positive and negative symptoms in patients with psychotic disorders were considered eligible. We developed a comprehensive electronic search strategy to identify peer-reviewed studies in Pubmed, Embase, PsycINFO and CINAHL covering all dates up to the search date in May 2020 with no language restriction. The references of published articles were hand-searched for additional materials. The authors of published articles were contacted for newer or unpublished data. Risk of bias was assessed by Appraisal of Cross-sectional Studies (AXIS). Results: A total 11 cross-sectional studies (n = 255) with low-to-moderate quality, were selected for the systematic review. 8 of them addressed the association between sleep spindle activity and cognitive functions (n = 193), of which 6 studies reported positive correlations (r only reported in 4 studies, from 0.45 to 0.75). Out of multiple cognitive domains, we have only found attention/cognitive processing speed to have a more consistent positive association with sleep spindle activity. On the other hand, 8 studies investigated the relationship between sleep spindle and positive/negative symptom severity (n = 190), but findings were inconsistent. Spindle density is the most consistent parameter correlating with cognitive functions, while the best spindle parameter for correlating with positive and negative symptom severity cannot be identified due to mixed results. Discussion: This systematic review confirms the linkage between sleep spindle activity and cognitive functions. However, included studies had small sample sizes, with high risks of sampling and response bias. Moreover, confounders were often not controlled. The heterogeneous report of spindle parameters and use of cognitive assessment tools rendered meta-analysis infeasible. It is necessary to examine the longitudinal change of sleep spindle activity with the course of illness, as well as the effect of sleep spindle enhancing agents on cognitive function. |
| first_indexed | 2024-12-19T13:31:45Z |
| format | Article |
| id | doaj.art-6449ae18491a4373822b42ae89be1c87 |
| institution | Directory Open Access Journal |
| issn | 2590-1427 |
| language | English |
| last_indexed | 2024-12-19T13:31:45Z |
| publishDate | 2020-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Sleep Medicine: X |
| spelling | doaj.art-6449ae18491a4373822b42ae89be1c872022-12-21T20:19:21ZengElsevierSleep Medicine: X2590-14272020-12-012100025Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosisChi Hung Au0Christopher-James Harvey1Queen Mary Hospital, Hong Kong; Corresponding author.Imperial College London, UKBackground: Sleep disturbances are associated with worse cognitive and psychotic symptoms in individuals with schizophrenia. Growing literature reveals sleep spindle deficits in schizophrenia may be an endophenotype reflecting a dysfunctional thalamo-thalamic reticular nucleus-cortical circuit. Since thalamic functions link to cognitive, positive and negative symptoms, it is possible that sleep spindle activity is associated with these symptoms. The primary objectives of this systematic review were to assess the associations of sleep spindle activity in psychotic patients with 1) cognitive functions; and 2) positive and negative symptom severity. A secondary objective was to examine which spindle parameter would be the most consistent parameter correlating with cognitive functions, and positive and negative symptoms. Method: Observational studies reporting an association between sleep spindle activity and cognitive functions, positive and negative symptoms in patients with psychotic disorders were considered eligible. We developed a comprehensive electronic search strategy to identify peer-reviewed studies in Pubmed, Embase, PsycINFO and CINAHL covering all dates up to the search date in May 2020 with no language restriction. The references of published articles were hand-searched for additional materials. The authors of published articles were contacted for newer or unpublished data. Risk of bias was assessed by Appraisal of Cross-sectional Studies (AXIS). Results: A total 11 cross-sectional studies (n = 255) with low-to-moderate quality, were selected for the systematic review. 8 of them addressed the association between sleep spindle activity and cognitive functions (n = 193), of which 6 studies reported positive correlations (r only reported in 4 studies, from 0.45 to 0.75). Out of multiple cognitive domains, we have only found attention/cognitive processing speed to have a more consistent positive association with sleep spindle activity. On the other hand, 8 studies investigated the relationship between sleep spindle and positive/negative symptom severity (n = 190), but findings were inconsistent. Spindle density is the most consistent parameter correlating with cognitive functions, while the best spindle parameter for correlating with positive and negative symptom severity cannot be identified due to mixed results. Discussion: This systematic review confirms the linkage between sleep spindle activity and cognitive functions. However, included studies had small sample sizes, with high risks of sampling and response bias. Moreover, confounders were often not controlled. The heterogeneous report of spindle parameters and use of cognitive assessment tools rendered meta-analysis infeasible. It is necessary to examine the longitudinal change of sleep spindle activity with the course of illness, as well as the effect of sleep spindle enhancing agents on cognitive function.http://www.sciencedirect.com/science/article/pii/S2590142720300148Sleep spindlePsychosisCognitive functionPositive symptomNegative symptom |
| spellingShingle | Chi Hung Au Christopher-James Harvey Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis Sleep Medicine: X Sleep spindle Psychosis Cognitive function Positive symptom Negative symptom |
| title | Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis |
| title_full | Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis |
| title_fullStr | Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis |
| title_full_unstemmed | Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis |
| title_short | Systematic review: the relationship between sleep spindle activity with cognitive functions, positive and negative symptoms in psychosis |
| title_sort | systematic review the relationship between sleep spindle activity with cognitive functions positive and negative symptoms in psychosis |
| topic | Sleep spindle Psychosis Cognitive function Positive symptom Negative symptom |
| url | http://www.sciencedirect.com/science/article/pii/S2590142720300148 |
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