Dataset Information

Neurocognitive functioning of individuals with schizophrenia: using and not using drugs.

ABSTRACT:

Objectives

Research on neurocognition in schizophrenia, using modest samples and self-rated assessments, reports drug use contributes to improved rather than impaired cognitive function. We have sought to replicate these findings in a large sample of patients that had their drug-use status confirmed by laboratory assays and evaluated the potential differences in cognitive function between patients with positive and negative results.

Methods

Nine hundred and seventy four schizophrenia patients completed neuropsychological and laboratory tests at screening/baseline of the Clinical Antipsychotic Trials of Intervention Effectiveness study. Radioimmunoassay (RIA) of hair tested for cannabis, cocaine and methamphetamine.

Results

Many patients screened positive for drug use (n = 262; 27%), and there were no differences between patients with positive and negative results in terms of cognitive function after adjusting for multiple inference testing, except patients with positive RIA for methamphetamine demonstrated increased processing speed (corrected, P = .024). Moderator models were employed to explore potential subgroup differences in this pattern of results. At low medication dosages, patients with positive RIA for cocaine demonstrated decreased processing speed compared with patients with negative RIA for cocaine (uncorrected, P = .008). And for any other drugs with low psychopathology, patients with positive RIA demonstrated decreased working memory compared with patients with negative RIA (uncorrected, P = .006).

Conclusions

No positive effects of cannabis on cognitive function were observed, and drug use was not associated with improved neurocognition across most of the subgroup characteristics explored in this sample of schizophrenia patients.

SUBMITTER: Bahorik AL

PROVIDER: S-EPMC4059433 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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Publications

Neurocognitive functioning of individuals with schizophrenia: using and not using drugs.

Bahorik Amber L AL Newhill Christina E CE Eack Shaun M SM

Schizophrenia bulletin 20130724 4

<h4>Objectives</h4>Research on neurocognition in schizophrenia, using modest samples and self-rated assessments, reports drug use contributes to improved rather than impaired cognitive function. We have sought to replicate these findings in a large sample of patients that had their drug-use status confirmed by laboratory assays and evaluated the potential differences in cognitive function between patients with positive and negative results.<h4>Methods</h4>Nine hundred and seventy four schizophre ...[more]

PMID: 23884348

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Project description:ImportanceNeurocognitive functioning is a potential biomarker to advance detection, prognosis, and preventive care for individuals at clinical high risk for psychosis (CHR-P). The current consistency and magnitude of neurocognitive functioning in individuals at CHR-P are undetermined.ObjectiveTo provide an updated synthesis of evidence on the consistency and magnitude of neurocognitive functioning in individuals at CHR-P.Data sourcesWeb of Science database, Cochrane Central Register of Reviews, and Ovid/PsycINFO and trial registries up to July 1, 2020.Study selectionMultistep literature search compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology performed by independent researchers to identify original studies reporting on neurocognitive functioning in individuals at CHR-P.Data extraction and synthesisIndependent researchers extracted the data, clustering the neurocognitive tasks according to 7 Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) domains and 8 CHR-P domains. Random-effect model meta-analyses, assessment of publication biases and study quality, and meta-regressions were conducted.Main outcomes and measuresThe primary effect size measure was Hedges g of neurocognitive functioning in individuals at CHR-P (1) compared with healthy control (HC) individuals or (2) compared with individuals with first-episode psychosis (FEP) or (3) stratified for the longitudinal transition to psychosis.ResultsA total of 78 independent studies were included, consisting of 5162 individuals at CHR-P (mean [SD; range] age, 20.2 [3.3; 12.0-29.0] years; 2529 [49.0%] were female), 2865 HC individuals (mean [SD; range] age, 21.1 [3.6; 12.6-29.2] years; 1490 [52.0%] were female), and 486 individuals with FEP (mean [SD; range] age, 23.0 [2.0; 19.1-26.4] years; 267 [55.9%] were female). Compared with HC individuals, individuals at CHR-P showed medium to large deficits on the Stroop color word reading task (g = -1.17; 95% CI, -1.86 to -0.48), Hopkins Verbal Learning Test-Revised (g = -0.86; 95% CI, -1.43 to -0.28), digit symbol coding test (g = -0.74; 95% CI, -1.19 to -0.29), Brief Assessment of Cognition Scale Symbol Coding (g = -0.67; 95% CI, -0.95 to -0.39), University of Pennsylvania Smell Identification Test (g = -0.55; 95% CI, -0.97 to -0.12), Hinting Task (g = -0.53; 95% CI, -0.77 to -0.28), Rey Auditory Verbal Learning Test (g = -0.50; 95% CI, -0.78 to -0.21), California Verbal Learning Test (CVLT) (g = -0.50; 95% CI, -0.64 to -0.36), and National Adult Reading Test (g = -0.52; 95% CI, -1.01 to -0.03). Individuals at CHR-P were less impaired than individuals with FEP. Longitudinal transition to psychosis from a CHR-P state was associated with medium to large deficits in the CVLT task (g = -0.58; 95% CI, -1.12 to -0.05). Meta-regressions found significant effects for age and education on processing speed.Conclusions and relevanceFindings from this meta-analysis support neurocognitive dysfunction as a potential detection and prognostic biomarker in individuals at CHR-P. These findings may advance clinical research and inform preventive approaches.

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Project description:Background and purposeSmall vessel disease is a major cause of neurocognitive dysfunction in the elderly. Small vessel disease may manifest as white matter hyperintensities, lacunar infarcts, cerebral microbleeds, and atrophy, all of which are visible on conventional MR imaging or as microstructural changes determined by diffusion tensor imaging. This study investigated whether microstructural integrity is associated with neurocognitive dysfunction in older individuals, irrespective of the conventional features of small vessel disease.Materials and methodsThe study included 195 participants (75 years of age or older) who underwent conventional 3T MR imaging with DTI to assess fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. Cognitive tests were administered to assess cognitive domains, and the Geriatric Depression Scale-15 and Apathy Scale of Starkstein were used to assess symptoms of depression and apathy, respectively. The association between DTI measures and neurocognitive function was analyzed by using linear regression models.ResultsIn gray matter, a lower fractional anisotropy and higher mean diffusivity, axial diffusivity, and radial diffusivity were associated with worse executive function, psychomotor speed, and overall cognition and, in white matter, also with memory. Findings were independent of white matter hyperintensities, lacunar infarcts, and cerebral microbleeds. However, after additional adjustment for normalized brain volume, only lower fractional anisotropy in white and gray matter and higher gray matter radial diffusivity remained associated with executive functioning. DTI measures were not associated with scores on the Geriatric Depression Scale-15 or the Apathy Scale of Starkstein.ConclusionsMicrostructural integrity was associated with cognitive but not psychological dysfunction. Associations were independent of the conventional features of small vessel disease but attenuated after adjusting for brain volume.

Dataset Information

Neurocognitive functioning of individuals with schizophrenia: using and not using drugs.

Objectives

Methods

Results

Conclusions

Publications

Neurocognitive functioning of individuals with schizophrenia: using and not using drugs.

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