The Impact of co-morbid severe mental illness and HIV upon mental and physical health and social outcomes: a systematic review

Our aim was to review the evidence related to the impact of co-morbid severe mental illness SMI (schizophrenia, schizoaffective and bipolar disorder) and HIV upon mental health, physical health and social outcomes. We carried out a systematic review of scientific evidence, searching online databases (MEDLINE, PsychInfo, EMBASE, Global Health and Scopus) for studies between 1983 and 2017 using search terms for SMI and HIV. Studies were included if they compared health or social outcomes between people living with co-morbid SMI and HIV and people living with either: a) HIV only; or b) SMI only. Outcomes of interest were: mortality, health service use, HIV/SMI-related, co-morbidities, and social outcomes. We identified 20 studies which met our inclusion criteria. Although studies were generally high quality, there was heterogeneity in both selection of outcomes and choice of measure. It was therefore difficult to draw strong conclusions regarding the impact of co-morbid SMI and HIV across any outcome. We found little evidence that co-morbid SMI and HIV were associated with lower levels of treatment, care or poorer clinical outcomes compared to people living with SMI or HIV alone. However, mortality appeared to be higher among the co-morbid group in three out of four analyses identified. Physical and mental co-morbidities and social outcomes were rarely measured. Limited data mean that the impact of co-morbid SMI and HIV is uncertain. In order to develop evidence-based guidelines, there is an urgent need for further research. This may be realized by exploring opportunities for using data from existing cohort studies, routinely collected data and data linkage to investigate important questions relating to this neglected but potentially important area.