The association between psychiatric illness and HIV transmission risk behaviours has been seen across a wide range of populations, including adult men and women, men who have sex with men, minority women, substance users, gay and bisexual men and adolescents and young adults. Having neurocognitive impairment is also thought to contribute to the ongoing transmission of HIV, as it can impair decision making and suppress behavioural inhibitions. Thus, treating psychiatric and neurocognitive disorders in HIV is a much needed and important area of focus to benefit the health of individuals living with HIV and also the public health.

Despite the advances in our knowledge of and treatments for HIV, the negative psychological impact of HIV infection has not been eliminated. Most people with serious, progressive illness confront a range of psychological and behavioural challenges including adherence to complex and sometimes toxic medication regimens, the prospect of real and anticipated losses (at the personal, familial and community levels), changes in quality of life, the fear of significant physical decline and death and coping with the uncertainty of the illness course. HIV/AIDS brings additional challenges due to the stigma associated with the disease and the modes of transmission, and the fact that it is both infectious and potentially fatal. Addressing these challenges and providing psychiatric and other psychosocial interventions as early as possible has the potential to help these individuals cope more effectively with the disease and keep them linked to and in continuous care.

For some PLWH, there may be exacerbations of pre-existing psychiatric disorders, including substance abuse/dependence or precipitations of new onset disorders, in which psychiatric syndrome-specific treatment, sometimes including psychopharmacology, must be amongst the interventions provided. Studies have shown that adults living with HIV and/or at risk for acquiring HIV are at elevated risk for psychosocial distress and psychiatric conditions, particularly depression (see ^{1 2, 3}). Whilst the specific role of HIV is not clear, a number of these studies have found clear and important associations between the prevalence of psychiatric disorders and psychological symptomatology and poor quality of life, elevated sexual risk behaviour, poor adherence and poor health outcomes. For example, chronic and intermittent depressive symptoms in HIV-positive women are associated with disease progression, lower CD4 cell count and higher baseline viral load levels; and, in general, women with chronic depression have mortality rates twice as high as those with little or no depressive symptoms (see ^{4 5}). Thus, there is substantial evidence that diagnosing and treating psychiatric disorders, which are common amongst people living with HIV, can improve the quality of life as well as longevity.