Background: Substance use disorders account for a significant portion of the disease burden attributed to mental health globally, but measurement remains suboptimal. Studies assessing substance use typically rely on retrospective recall often over long periods of time. However, the episodic, contextual and event- or time-contingent nature of substance use call into question the validity of these traditional retrospective measurement methods. One method to overcome these limitations is ecological momentary assessment (EMA). EMA methods repeatedly sample participant behaviours and experiences in real time, in the context in which they occur. Objective: This review aimed to systematically identify studies using EMA in substance use measurement, provide a comprehensive overview of the EMA methods used, and to provide a draft framework for reporting and methodological recommendations for future EMA studies in this field. Methods: Studies published between 2018 and 2023 were sourced from PubMed, Medline, Scopus, and PsycINFO via Ovid databases on 31st January 2023 using terms related to EMA, digital phenotyping, passive sensing, daily diary and specific terms for each drug type. Studies that actively or passively assessed thoughts and/or behaviour, in the participants’ natural environment/daily lives, in a repeated manner, at or close to the behaviour of interest (substance use), using either automatic prompts or notifications were included. Studies were included for all populations, any age, in any setting, any study design, including RCTs or experimental designs. This study was preregistered on PROSPERO (CRD42023400418). Results: The search identified 7053 articles of which 858 were reviewed in full, and 273 (n = 70,831 participants) were included and extracted. Most studies were conducted in the United States (80%) and focused on alcohol (78%) and cannabis use (30%) with or without the presence of other substance use. Alcohol and cannabis measurement co-occurred the most in 44 (16%) studies. Psychedelics (2%) were particularly understudied using EMA methods. PCP, bath salts, and inhalants were only measured in one study each. We found limited reporting consistency with respect to compliance, completion windows, attrition rates, survey duration and data collection technologies in EMA substance use studies. Sensing data were measured in a limited number of studies. Conclusions: While EMA is a powerful tool for capturing dynamic behaviours, inconsistencies in reporting and design transparency persist. Improving reporting practices, smart sensing and wearable integration, compliance monitoring alongside expanding EMA to underexplored substances such as psychedelics, will be critical to enhancing data quality and advancing the field.
