Abstract
INTRODUCTION: People living with HIV (PLHIV) frequently face psychological challenges, including stigma, stress and social isolation, which can negatively affect adherence to antiretroviral therapy (ART). Even in high-income countries where treatment is accessible, poor adherence can lead to drug resistance, reduced immune function and early morbidity. This systematic review aims to synthesise evidence on the relationship between psychological and mental health factors and ART adherence among PLHIV in high-income settings. METHODS AND ANALYSIS: We will include studies published in any language between January 2015 and the date of the last searches. Reports of studies published in languages other than English, and which appear to be eligible for inclusion after the first level of screening, will be translated using Google Translate.Studies will be included if they continue to meet the inclusion criteria and the quality of the translation is sufficient to extract the relevant data. PLHIV aged ≥15 years receiving ART in high-income countries. The studies to be included must assess psychological or mental health variables and ART adherence. Peer-reviewed journal articles will be the primary source of evidence. Grey literature identified from reference lists of key articles or using Google Advanced search techniques will be included. Searches for published studies will be done in OVID Medline, PsycINFO and Embase. Cochrane CENTRAL will be used to identify clinical trials in ClinicalTrials.gov and the International Clinical Trials Registry Platform.Two independent reviewers will assess study quality and risk of bias using the Newcastle-Ottawa Scale, National Institutes of Health (NIH) Quality Assessment Tool and Jadad Scale. Discrepancies will be resolved by a third reviewer. Synthesis of quantitative data will be primarily descriptive. Predictors that have been examined in three or more studies will be reported in detail while those assessed in fewer studies will be presented concisely. ETHICS AND DISSEMINATION: This study will be a review of the literature and will not involve primary collection of patients' data. We will include amendments to the protocol in the final review. The final study will be published in a peer-reviewed journal and presented at conferences. The results of this systematic review will inform clinical practice, guide future research and support policy development that minimise mental health barriers to ART adherence. PROSPERO REGISTRATION NUMBER: CRD420251102248.