Chronic Tobacco-Smoking on Psychopathological Symptoms, Impulsivity and Cognitive Deficits in HIV-Infected Individuals

Abstract

HIV-infected individuals (HIV+) has 2-3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.

Keywords: Decision making; HIV; Psychopathology; Risk; Tobacco use.

Figure 1. Psychopathological Symptoms and Depression Scale

A) On Symptom Checklist-90, both tobacco-Smokers and HIV+ participants had higher scores and more psychopathological symptoms than SN. HIV+Smokers had the highest scores, with more symptoms, on depression and obsessive compulsiveness, as well as the global scores. B) On the Center for Epidemiological Studies-Depression (CES-D) scale, HIV+ participants (regardless of smoking status) and tobacco-Smokers (regardless of HIV serostatus) had greater depressive symptoms, with the HIV+Smoker group reporting the greatest depressive symptoms.

Figure 2. Barratt Impulsivity Scale

(A) The Barratt Impulsivity Scale shows higher Total Scores in both HIV+ individuals (regardless of smoking status) and in Tobacco Smokers (regardless of HIV status), and the highest Total score in the HIV+Smoker group. (B & C) On the two-factor model, HIV+ participants tended to have higher scores than SN on Cognitive Impulsivity, while chronic Smokers had higher Behavioral Impulsivity. Therefore, HIV+Smokers had the highest scores on both cognitive and behavioral impulsivity scores.

Figure 3. Iowa Gambling Task (IGT) and Wisconsin Card Sort Test

(A & B) The Iowa Gambling Task (IGT) shows that the effect of HIV+ depends on smoking status for advantageous choices made and for the money lost. While SN Smokers had better performance than SN-nonSmokers, with more advantageous choices and loss less money, HIV+Smokers made more disadvantageous choices and lost more money than HIV+ non-Smokers. C) On the Wisconsin Card Sort Task, HIV+ participants, significantly had higher % errors, significantly higher in those who were Smokers, and Smokers (regardless of HIV serostatus) also tended to have more errors; therefore, HIV+Smokers had the highest error percentages.

Figure 4. Performance on Cognitive Domain (Z-scores)

Performance (Z-scores) in the seven cognitive domains assessed across all four groups. HIV+ participants (regardless of Smoker status) performed worse on all seven domains, which led to worse performance on the Global score. SN-Smokers also tended to perform worse than SN non-smokers which led to a trend for the lower Global score. Hence HIV+ and Smoker status showed an additive effect, leading to lowest scores in all domain scores and the Global scores in HIV+Smokers.

Figure 5. Correlations Between Cognitive Function and Psychopathological Symptoms

A) Correlations between memory z-score and WCST % error: only HIV+ smokers with poorer memory had more errors on the WCST (r=−0.66, p=0.01); the other three groups showed no significant correlations (r= 0.09 to −0.27; p=0.24 to 0.74). B–F): Lower attention z-scores were associated with greater psychopathological symptoms, including obsessive compulsiveness, phobic anxiety, somatization, positive symptom distress index as well as general symptom index.