Abstract
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.
A-09 Attention in individuals with Heroin dependence measured by digit span versus continuous performance test