Cortisol Response Mediates HIV-1-Related Cognitive Deficits Among Injecting Drug Abusers

The cortisol response is an important measure of the endocrine activity to environmental challenges and has been related to cognitive function and mood. Previous studies have shown that the cortisol response to stress is dysregulated in persons with HIV-1 infection. Since cortisol is neurotoxic and its levels have been related to cognitive dysfunction in various disorders, it is possible that neuroendocrine dysregulation may also be related to cognitive dysfunction in individuals with HIV-1 infection. The purpose of this study was to test the hypothesis that the cortisol response to an alpha adrenergic challenge, cold pressor, is related to cognitive function in HIV-infected injecting drug abusers. We used growth curve modeling to study the relationship of cold pressor challenge stimulated cortisol response to scores on the modified HIV Dementia Scale (mHDS). To test this hypothesis, we assessed the effects of HIV-1 infection on the HDS score directly and indirectly via pattern of cortisol response. The analysis showed that HIV-1 infection was directly related to mHDS performance and that it also influenced scores on the mHDS by way of individuals’ pattern of cortisol response. Cortisol response to α-adrenergic challenge thus may mediate cognitive deficits in individuals with HIV-1 infection. These findings further emphasize the importance of understanding the role of stress in the cognitive problems associated with HIV-1 infection.