Sustained attention and vigilance deficits associated with HIV and a history of methamphetamine dependence

Abstract

Background: Human immunodeficiency virus (HIV)-associated neurocognitive disorders persist in the era of antiretroviral therapy. One factor that is elevated among persons with HIV (PWH) and independently associated with neurocognitive impairment is methamphetamine dependence (METH). Such dependence may further increase cognitive impairment among PWH, by delaying HIV diagnosis (and thus, antiretroviral therapy initiation), which has been posited to account for persistent cognitive impairment among PWH, despite subsequent treatment-related viral load suppression (VLS; <50 copies of the virus per milliliter in plasma or cerebrospinal fluid). This study examined the main and interactive (additive versus synergistic) effects of HIV and history of METH on the sustained attention and vigilance cognitive domain, while controlling for VLS.

Methods: Participants included 205 (median age = 44 years; 77% males; HIV-/METH- n = 67; HIV+/METH - n = 49; HIV-/METH+ n = 36; HIV+/METH+ n = 53) individuals enrolled in the Translational Methamphetamine AIDS Research Center, who completed Conners' and the 5-Choice continuous performance tests (CPTs).

Results: METH participants exhibited deficits in sustained attention and vigilance; however, these effects were not significant after excluding participants who had a positive urine toxicology screen for methamphetamine. Controlling for VLS, PWH did not have worse sustained attention and vigilance, but consistently displayed slower reaction times across blocks, relative to HIV- participants. There was no HIV x METH interaction on sustained attention and vigilance.

Conclusions: Recent methamphetamine use among METH people and detectable viral loads are detrimental to sustained attention and vigilance. These findings highlight the need for prompt diagnosis of HIV and initiation of antiretroviral therapy, and METH use interventions.

Keywords: Continuous performance test; Human immunodeficiency virus; Methamphetamine; Sustained attention; Vigilance.

Figure 1.

Effects of human immunodeficiency virus (HIV) and history of methamphetamine dependence (METH) on 5C-CPT performance. N = 203. METH+ had lower d prime, relative to METH- people (A). There were no main or interactive effects of HIV and METH on any of the other outcome variables (B – I). Data are presented as means, with error bars representing standard error of the mean. Significant differences are denoted with an asterisk. Corresponding regression estimates, standard errors, and bootstrapped 95% confidence intervals presented in Table 2.

Figure 2.

Effects of human immunodeficiency virus (HIV) and history of methamphetamine dependence (METH) on 5C-CPT performance across trial blocks. N = 203. Overall performance on the 5C-CPT decreased across blocks. METH+ participants exhibited poorer 5C-CPT performance relative to METH- participants, irrespective of HIV status, as measured by d prime (A). METH+ participants had significantly poorer responsivity index, compared to METH- participants, however, this was not significant following Bonferroni correction (B). Impaired responding to targets was more exaggerated as time progressed and among METH+ participants, compared to METH- participants (C). False alarm rates did not differ across blocks, or according to HIV. METH+ participants had more false alarms compared to METH- participants, however, this effect was not significant follow Bonferroni correction (D). HIV+ had lower accuracy, compared to HIV-negative people (E). The number of omissions significantly increased across trial blocks. METH+ participants had significantly elevated misses to targets (% omission; F). Reaction time slowed over trial blocks and HIV+ had significantly slower reaction time, relative to HIV- subjects (G). Finally, premature responses did not differ across blocks, or according to HIV. METH+ participants had significantly more premature responses, however, this effect was not significant following Bonferroni correction (H). Data are presented as means, with error bars representing standard error of the mean. Corresponding regression estimates, standard errors, and bootstrapped 95% confidence intervals presented in Table 4.

Figure 3.

Effects of human immunodeficiency virus (HIV) and history of methamphetamine dependence (METH) on Conners’ CPT performance. N = 203. There was a significant HIV x METH interaction on attention-deficit/ hyperactivity disorder (ADHD) confidence index (prior to Bonferroni correction), such that among HIV-people, METH+ was associated with greater ADHD confidence index. METH+ was not associated with ADHD confidence index among people with HIV (A). There were no main or interactive effects of HIV and METH on any of the other outcome variables (A – F). Data are presented as means, with error bars representing standard error of the mean. Significant difference prior to Bonferroni correction (i.e., p<.05) is denoted with a †. Corresponding regression estimates, standard errors, and bootstrapped 95% confidence intervals presented in Table 5.

Figure 4.

Effects of human immunodeficiency virus (HIV) and history of methamphetamine dependence (METH) on Conners’ CPT performance across trial blocks.. N = 203. Omissions increased across blocks. METH+ participants exhibited greater omissions, relative to METH- participants (A). False alarm rates also increased across blocks; however, false alarm rates did not differ according to HIV or METH status (B). HIV+ had significantly slower reaction time compared to HIV- subjects. Similarly, METH+ had significantly slower reaction time compared to METH- participants (C). Reaction time error increased across blocks. METH+ participants exhibited greater RT error, than METH- participants (D). Data are presented as means, with error bars representing standard error of the mean. Corresponding regression estimates, standard errors, and bootstrapped 95% confidence intervals presented in Table 7.