NIDA-supported researchers have tallied the burden that methamphetamine use and human immunodeficiency virus (HIV) impose on daily functioning. Their findings yielded clinically relevant insights and clues to potentially helpful interventions.
Dr. Steven Paul Woods and colleagues at the Translational Methamphetamine AIDS Research Center at the University of California in San Diego assessed 798 individuals’ daily functioning in four areas:
- Everyday cognitive symptoms, including problems with memory, communication, and higher-level intellectual performance
- Instrumental (skilled) activities of daily living, including medication and financial management, grocery shopping, understanding of reading material and television, and planning of social activities
- Basic activities of daily living, including housekeeping, making home repairs, bathing, and dressing
- Employment
Figure. Methamphetamine Use and HIV Infection Raise the Risk for Functional Dependence Compared with study participants who were not infected with HIV and did not use methamphetamine (HIV−/MA−), participants using methamphetamine (HIV−/MA+) and those infected with HIV (HIV+/MA−) showed similar increases in functional dependence—the need for assistance with everyday tasks. Methamphetamine users with HIV (HIV+/MA+) showed the highest levels of functional dependence in most domains of daily life.
- Text description of Figure
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The figure shows a bar graph indicating the proportion of study participants infected or not infected with HIV and using or not using methamphetamine who were functionally dependent in five different domains of daily life. The vertical (y)-axis shows the proportion of functionally dependent participants (in percent), and the horizontal (x)-axis shows the type of functional dependence, that is, having global functional dependence, having everyday cognitive symptoms, requiring assistance with skilled activities, requiring assistance with basic activities, or lacking employment. Levels of functional dependence were lowest among study participants not infected with HIV and not using methamphetamine (indicated by dark blue bars), with about 30 percent, 30 percent, 25 percent, 15 percent, and 40 percent of this group being functionally dependent in domains 1 to 5, respectively. Among participants not infected with HIV and using methamphetamine (indicated by medium-dark blue bars), about 55 percent, 60 percent, 45 percent, 15 percent, and 60 percent were functionally dependent in each of the five domains, respectively. Among participants infected with HIV and not using methamphetamine (indicated by medium-light blue bars), about 60 percent, 55 percent, 50 percent, 20 percent, and 60 percent were functionally dependent in each of the five domains. And participants both infected with HIV and using methamphetamine (indicated by light blue bars), showed the highest levels of functional dependence in almost all domains, with 70 percent, 60 percent, 55 percent, 15 percent, and 80 percent being functionally dependent in each of the five domains.
The San Diego researchers classified participants who reported difficulties that were extensive or severe enough to suggest a substantial need for help in at least two areas as “globally functionally dependent.” The prevalence of global functional dependence was roughly twice as high among the 581 participants who used methamphetamine, had HIV, or both, as among those who were methamphetamine and HIV free (see Figure). The greatest disparities were in everyday cognitive abilities and skilled activities of daily living.
The HIV-infected methamphetamine users were more likely to be globally dependent than the methamphetamine users who did not have HIV infection. They also had a markedly higher unemployment rate, 83 percent, than either of the singly affected groups.
The researchers attributed these differences mainly to the effects of methamphetamine and HIV disease, noting that all four groups had comparable rates of general health problems typically seen in stimulant users. These included, for example, histories of alcohol abuse, depression, or hepatitis C infection.
The researchers also assessed which specific clinical problems might underlie functional dependence among the HIV-infected methamphetamine users. The most prominent problem was low cognitive reserve (that is, a reduced ability to recruit secondary brain networks to perform cognitive tasks when primary networks are damaged). Dependent dually affected participants also were more likely to have low overall cognitive capacity, to have used multiple addictive substances, and to have received a diagnosis of major depressive disorder.
On the basis of these results, Dr. Woods and colleagues recommend that clinicians carefully monitor medication compliance among patients who use methamphetamine, have HIV, or both. Study collaborator Ms. Kaitlin Blackstone explains that cognitively impaired patients “tend to make errors of omission,” which may include forgetting to take medications. Anti-HIV medication regimens in particular are very demanding, and patients who fail to adhere strictly to them may incur clinical setbacks.
Cell Counts and Daily Functioning
Among the participants with HIV infection, the researchers found, methamphetamine use increased the risk for global functional dependence only among those whose CD4 cell counts had never fallen below 200. Additional analysis of the study data indicated that a history of alcohol addiction contributed more to these patients’ functional dependence than methamphetamine did. Possibly, the reason why methamphetamine was not associated with global functional dependence among patients who had experienced very low CD4 cell counts is that such severe HIV-induced immunosuppression causes extensive damage to the brain that outstrips or masks that caused by methamphetamine.
Dr. Woods observes that today many HIV-infected patients avoid severe immunosuppression thanks to antiretroviral medication, and so remain susceptible to functional dependence promoted by the stimulant drug and alcohol. “Clinicians should pay closer attention to the possible role of methamphetamine use and alcohol in functional dependence among people living with HIV,” Dr. Woods advises.
To Make Life Better
Dr. Woods says that his team’s long-term goal is to identify functional needs and develop interventions to better the lives of people affected by methamphetamine use and HIV. However, Dr. Woods says, “We are only in very early stages of investigating the effects of such interventions.”
The researchers suggest that interventions to improve memory and enhance psychomotor speed may increase independence among methamphetamine users and among those with HIV. For dually affected individuals in particular, assistance in finding and keeping jobs could also improve quality of life. Along with financial security, work provides community and self-esteem. To be most effective, employment services for this population might aim to minimize the impact of clients’ cognitive impairments on functioning in work contexts, focus on motivational support to counter depression and the sense of helplessness that addiction and HIV can engender, and address workplace drug policies and stigma against people with HIV.
This study was supported by NIH grants DA31098, DA12065, DA026306, DA032120, DA034362, and DA034510.
Source:
Blackstone, K.; Iudicello, J.E.; Morgan, E.E. et al. Human immunodeficiency virus infection heightens concurrent risk of functional dependence in persons with long-term methamphetamine use. Journal of Addiction Medicine 7(4):255–263, 2013. Full text