The DOI matches its Crossref record; 75 of the 78 references it cites were found in a registry or an index.
Overlooking the Obvious: A Meta-analytic Comparison of Digit Symbol Coding Tasks and Other Cognitive Measures in Schizophrenia
Abstract
CONTEXT: In focusing on potentially localizable cognitive impairments, the schizophrenia meta-analytic literature has overlooked the largest single impairment: on digit symbol coding tasks. OBJECTIVE: To compare the magnitude of the schizophrenia impairment on coding tasks with impairments on other traditional neuropsychological instruments. DATA SOURCES: MEDLINE and PsycINFO electronic databases and reference lists from identified articles. STUDY SELECTION: English-language studies from 1990 to present, comparing performance of patients with schizophrenia and healthy controls on coding tasks and cognitive measures representing at least 2 other cognitive domains. Of 182 studies identified, 40 met all criteria for inclusion in the meta-analysis. DATA EXTRACTION: Means, standard deviations, and sample sizes were extracted for digit symbol coding and 36 other cognitive variables. In addition, we recorded potential clinical moderator variables, including chronicity/severity, medication status, age, and education, and potential study design moderators, including coding task variant, matching, and study publication date. DATA SYNTHESIS: Main analyses synthesized data from 37 studies comprising 1961 patients with schizophrenia and 1444 comparison subjects. Combination of mean effect sizes across studies by means of a random effects model yielded a weighted mean effect for digit symbol coding of g = -1.57 (95% confidence interval, -1.66 to -1.48). This effect compared with a grand mean effect of g = -0.98 and was significantly larger than effects for widely used measures of episodic memory, executive functioning, and working memory. Moderator variable analyses indicated that clinical and study design differences between studies had little effect on the coding task effect. Comparison with previous meta-analyses suggested that current results were representative of the broader literature. Subsidiary analysis of data from relatives of patients with schizophrenia also suggested prominent coding task impairments in this group. CONCLUSION: The 5-minute digit symbol coding task, reliable and easy to administer, taps an information processing inefficiency that is a central feature of the cognitive deficit in schizophrenia and deserves systematic investigation.
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“The DSST, a cognitive performance measure that assesses a variety of cognitive functions including processing speed and executive functions, has demonstrated strong correlation with overall cognitive functioning and functional outcomes in patients with acute depression (Raskin et al, 2007), schizophrenia (Dickinson et al, 2007), and bipolar disorders (Robinson et al, 2006).”
From A Randomized, Placebo-Controlled, Active-Reference, Double-Blind, Flexible-Dose Study of the Efficacy of Vortioxetine on Cognitive Function in Major Depressive Disorder (2015) · cites this paper as Dickinson et al, 2007
In the citing paper
“High rates of cognitive impairment in individuals experiencing psychosis have been found across multiple cognitive domains (Bokat & Goldberg, 2003;Dickinson et al., 2007;Mesholam-Gately et al., 2009).”
From Mindfulness for voices: An experimental analogue study of the effect of manipulating response style to simulated voices in a non‐clinical population. (2023) · cites this paper as Dickinson et al., 2007
In the citing paper
“Processing speed is a particularly important cognitive ability that is the most impaired domain of functioning in several neuropsychiatric conditions.”
From Domains of cognition and their assessment (2019) · cites this paper as [63]
In the citing paper
“performance on various coding tasks is not only the most significant impairment in schizophrenia 63 but is also the cognitive ability domain that is most strongly correlated with impairments in everyday functioning.”
From Domains of cognition and their assessment (2019) · cites this paper as [63]
Citations
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Memory Impairment in Schizophrenia: A Meta-Analysis
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3 of the 78 references couldn’t be matched to a known paper.
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Administration and interpretation of the Trail Making Test
Bowie, C. R., & Harvey, P. D. (2006) · Nature Protocols · doi:10.1038/nprot.2006.390 · Cited by 1,418
Neurocognition in first-episode schizophrenia: a meta-analytic review.
Mesholam-Gately, R. I., Giuliano, A. J., Goff, K. P., Faraone, S. V., & Seidman, L. J. (2009) · Neuropsychology · doi:10.1037/a0014708 · Cited by 1,130
Jauhar, S., Johnstone, M., & McKenna, P. J. (2022) · The Lancet · doi:10.1016/s0140-6736(21)01730-x · Cited by 1,116
Schizophrenia, “just the facts” 4. Clinical features and conceptualization
Tandon, R., Nasrallah, H. A., & Keshavan, M. S. (2009) · Schizophrenia Research · doi:10.1016/j.schres.2009.03.005 · Cited by 1,101
Snyder, H. R., Miyake, A., & Hankin, B. L. (2015) · Frontiers in Psychology · doi:10.3389/fpsyg.2015.00328 · Cited by 946
Metadata
- Authors
- Dickinson, D., Ramsey, M. E., & Gold, J. M.
- Affiliations
- University of Maryland, Baltimore (US)
- Venue
- Archives of General Psychiatry
- Publisher
- American Medical Association (AMA)
- Published
- 2007-05-01
- Volume
- 64
- Issue
- 5
- Pages
- 532
- ISSN
- 0003-990X (ISSN-L)
- OpenAlex
- W2037807133
- Semantic Scholar
- 95bdf0a9d300a85fa492784e96c7f169de258e06
- Cited by
- 863
- References
- 78
- Citations by year
- 2026: 13 · 2025: 29 · 2024: 33 · 2023: 33 · 2022: 35 · 2021: 50 · 2020: 51 · 2019: 55 · 2018: 52 · 2017: 46 · 2016: 40 · 2015: 66 · 2014: 61 · 2013: 69 · 2012: 51
- FWCI
- 25.84
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Archives of General Psychiatry (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health (5p30mh068580-03)
- National Institute of Mental Health (R21MH067764, MH-67764, MH 68580)
- Topics
- Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
- Social Sciences › Arts and Humanities › Philosophy › Mental Health and Psychiatry
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Cognitive Abilities and Testing
- Keywords
- schizophrenia, Digit Symbol Substitution Test, cognitive impairment, neuropsychological assessment, episodic memory, executive function, working memory, relatives of schizophrenic patients, effect size comparison
- MeSH terms
- Adolescent, Adult, Attention, Cognition Disorders, Family, Female, Humans, Male, Memory Disorders, Memory, Short-Term, Neuropsychological Tests, Schizophrenia, Schizophrenic Psychology, Wechsler Scales, Recognition, Psychology
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