Neurocognitive impairment and medication adherence in HIV patients with and without cocaine dependence.

Cocaine abuse among HIV patients is associated with faster disease progression and mortality. This study examined the relationship between neurocognitive functioning and medication adherence in HIV patients with (n = 25) and without (n = 39) current cocaine dependence. Active users had greater neurocognitive impairment (mean T-score = 35.16 vs. 40.97, p < .05) and worse medication adherence (mean z-score = -0.44 vs. 0.27, p < .001). In a multiple regression model, neurocognitive functioning (ß = .33, p < .01) and cocaine dependence (ß = -.36, p < .01) were predictive of poorer adherence. There was a significant indirect effect of cocaine dependence on medication adherence through neurocognitive impairment (estimate = -0.15, p < .05), suggesting that neurocognitive impairment partially mediated the relationship between cocaine dependence and poorer adherence. These results confirm that cocaine users are at high risk for poor HIV outcomes and underscore the importance of treating both neurocognitive impairment and cocaine dependence among HIV patients.

Citicoline Treatment Improves Measures of Impulsivity and Task Performance in Chronic Marijuana Smokers: A Pilot BOLD fMRI Study.

OBJECTIVE: Citicoline is an endogenous nucleotide that has historically been used to treat stroke, traumatic brain injury, and cognitive dysfunction. Research has also shown that citicoline treatment is associated with improved cognitive performance in substance-abusing populations. We hypothesized that marijuana (MJ) smokers who received citicoline would demonstrate improvement in cognitive performance as well as increased neural efficiency during tasks of cognitive control relative to those who received placebo. METHOD: The current study tested this hypothesis by examining the effects of citicoline in treatment-seeking chronic MJ smokers. In an 8-week double-blind, placebo-controlled study, 19 MJ smokers were randomly assigned via a double-blind procedure to the citicoline (8 Males, 2 Females) or placebo group (9 Males, 0 Females). All participants completed fMRI scanning at baseline and after 8 weeks of treatment during two cognitive measures of inhibitory processing, the Multi Source Interference Test (MSIT) and Stroop Color Word Test, and also completed the Barratt Impulsiveness Scale (BIS-11), a self-report measure of impulsivity. RESULTS: Following the 8 week trial, MJ smokers treated with citicoline demonstrated significantly lower levels of behavioral impulsivity, improved task accuracy on both the MSIT and Stroop tasks, and exhibited significantly different patterns of brain activation relative to baseline levels and relative to those who received placebo. CONCLUSIONS: Findings suggest that citicoline may facilitate the treatment of MJ use disorders by improving the cognitive skills necessary to fully engage in comprehensive treatment programs.

Zolpidem increases GABA in depressed volunteers maintained on SSRIs.

Individuals with major depressive disorder (MDD) often use hypnotics like zolpidem (Ambien(®)) to improve sleep in addition to their selective serotonin reuptake inhibitor (SSRI) regimen. SSRIs act in part to restore disrupted GABAergic activity, but benzodiazepines and related drugs have been shown to lower GABA in a way that may be counter to these therapeutic effects. The present within-subject, single-blind, placebo-controlled study measured changes in GABA in the anterior cingulate (ACC) and thalamus of volunteers maintained on SSRIs for the treatment of MDD (n=14) following zolpidem (10mg) administration. In addition to neurochemical measurements obtained using proton magnetic resonance spectroscopy ((1)H MRS) at 4 T, a series of questionnaires were administered to assess subjective effects associated with acute zolpidem exposure. Zolpidem elevated GABA levels in both voxels of interest (P<0.05) in the depressed participants, which could imply normalization, given the lower baseline levels associated with depression. The subjective drug experience in the depressed cohort was similar to that reported previously by healthy volunteers, and no relationships existed between GABA increases and the observed behavioral effects. Aside from treating insomnia, using zolpidem in the presence of SSRIs may have some unidentified therapeutic effects for depressed individuals.