Overall, cocaine and methamphetamine users share similar neuropsychological profiles. However, cocaine appears to be more associated with working memory impairments, which are typically frontally mediated, while methamphetamine appears to be more associated with memory impairments that are linked with temporal and parietal lobe dysfunction.
Objective Heroin dependent individuals appear to have significant deficits in attention which can be assessed using digit span forward (DSF) or the continuous performance test (CPT). The current meta-analysis examined differences between DSF and CPT results in studies of heroin dependent participants. Data selection Two researchers independently searched nine databases (e.g., PsycINFO, Pubmed, ProceedingsFirst), extracted required data, and calculated effect sizes. Inclusion criteria identified studies that had (a) compared heroin-dependent groups to healthy controls and (b) matched groups on either age, education, or IQ (at least 2 out of 3). Studies were excluded if participants were reported to have Axis I diagnoses (other than heroin dependence) or comorbidities known to impact neuropsychological functioning. Ten articles were coded and analyzed for the current study. Data synthesis When examined together, DSF and CPT evidenced a moderate and statistically significant effect size estimate (g = 0.614, p = .002). Subgroup analysis did not reveal statistically significant differences between the two groups (Q-Between = 0.228, p = 0.633). The effect size for DSF was g = 0.535 (p = 0.001) and for CPT was g = 0.774 (p = 0.104). The heterogeneity of DSF was in the moderate range, I2 = 71.291%, p = 0.002 while the heterogeneity of CPT was in the large range I2 = 97.863%, p = 0.001. Conclusion Heroin dependent individuals appear to demonstrate similarly poor performance on DSF and CPT. Assuming that both tests measure the same construct, both appear to be sensitive to the effect of Heroin on attention.
Objective Late-life depression (LLD) has been associated with cognitive impairments in domains such as memory, processing speed, and executive functions (e.g., initiation). However, it is unclear whether or not LLD is associated with language fluency difficulties that are often seen in some forms of dementia. Broadly, letter fluency is often observed to be associated with frontal deficits while category fluency is thought to be linked to temporal lobe dysfunction. Both tests are commonly used to assess language in older adults. The current meta-analysis examined potential differences between letter and category fluency in LLD and the robustness of previous findings in this population. Data Selection Investigators searched eight databases including PubMed and PsycINFO using terms such as “neuropsychol*,” “late-life,” and “depression.” Studies were excluded if participants were diagnosed with severe mental illness, neurological or other medical conditions that impact neurocognition. Data Synthesis Independent coders extracted data from 27 studies (k = 10 letter fluency, k = 17 semantic fluency). The effect size for semantic fluency was g = 0.64 (p < 0.001) with significant heterogeneity I² = 73.53% (Q = 60.45, df = 16, p < 0.001). The effect size for letter fluency was g = 0.49 (p < 0.001) also with significant heterogeneity I² = 52.08% (Q = 18.78, df = 9, p < 0.027). Conclusions Depressed individuals exhibited poorer performance on both category and letter fluency when compared to controls. This may indicate that depressed elderly individuals have difficulty with initiating verbal responses regardless of whether these responses rely on semantic networks or executive control.
Objective A previous meta-analysis assessing the impact of heart failure (HF) on cognition found the HF group performed more poorly than the healthy control (HC) on global cognition measures. The study observed a medium effect and moderate heterogeneity when using the Mini-Mental Status Examination (MMSE) to measure HF’s impact on global cognition. The current meta-regression explores whether the mean age of the HF group moderates performance on the MMSE when comparing HF patients to HC. Data Selection Two researchers independently searched eight databases, extracted data, and calculated effect sizes as part of a larger study. Inclusion criteria were: (a) adults with a diagnosis of HF, (b) comparison of HF patients to HC, and (c) adequate data to calculate effect sizes. Articles were excluded if patients had other types of organ failure, the article was not available in English, or there was a risk of sample overlap with another included study. Twelve articles (HF n = 1166 and HC n = 1948) were included. The unrestricted maximum likelihood computational model was used for the meta-regression. Data Synthesis Studies included in the meta-regression evidenced a statistically significant medium effect size estimate with moderate heterogeneity (k = 12, g = 0.671, p < 0.001, I2 = 80.91%). The meta-regression was statistically significant (slope = −0.023, p = 0.0022, Qmodel = 5.26, df = 1, p = 0.022). Conclusions Individuals with HF performed more poorly on the MMSE than HC. Larger effect sizes on the MMSE were observed in studies with participants who were younger compared to studies with participants who were older. Future research should continue to delineate the impact of age on global cognition in individuals with HF.
Objective A previous meta-analysis utilized the Trail Making Test A (TMT-A) to measure the impact of heart failure (HF) on attention. A near medium effect size with moderate heterogeneity was observed, the HF group performed worse than healthy controls (HC). This study explores if the age of the HF group moderates differences in the performance of individuals with HF versus HC on TMT-A. Data Selection Two researchers searched eight databases, extracted data, and calculated effect sizes as part of a larger study. Inclusion criteria were: (a) adults with HF (New York Heart Association severity II or higher), (b) comparison to a HC group, (c) standardized neuropsychological/cognitive testing, and (d) adequate data to calculate effect sizes. Exclusion criteria were: (a) participants had other types of major organ failure, (b) the article was not in English, or (c) there was a risk of sample overlap with another included study. A total of six articles were included in this sub-study (Total HF n = 602 and HC n = 342). The unrestricted maximum likelihood computational model was used for the meta-regression. Data Synthesis Studies included in the meta-regression evidenced a statistically significant medium effect size estimate with moderate heterogeneity (k = 6, g = 0.636, p < 0.001, I2 = 56.85%). The meta-regression was statistically significant (slope = −0.0515, p = 0.0016, Qmodel = 9.86, df = 1, p = 0.0016). Conclusions Individuals with HF performed worse on the TMT-A than HC. Age accounted for a significant proportion of the observed heterogeneity in the meta-regression. Future research should examine the relationship of age on cognition in individuals with HF.
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