Abstract
Cognition in schizophrenia is difficult to assess in clinical settings due to the time required to administer traditional pen-and-paper tests, among other factors. Digital remote assessments completed on a smartphone offer an alternative that can reduce the burden on healthcare staff and patients, in addition to providing more nuanced cognitive profiles, especially when used in conjunction with smartphone data such as sleep. Building on previous work using the mindLAMP research app in international contexts, this paper presents a global multi-site pilot study to explore the validity of the app's digital cognitive assessments as proxies for traditional in-person assessments such as the gold standard MATRICS Consensus Battery (MCCB). Across one site in the U.S. (Boston) and two sites in India (Bangalore and Bhopal), a total of 56 participants with diagnoses of early-course schizophrenia or schizoaffective disorder were recruited between September 2024 and March 2025 to engage with the mindLAMP app for 30 days. Participants completed 2-3 different cognitive tasks and surveys each day; at the beginning and the end of this period, participants also took the MCCB and surveys related to their diagnosis. mindLAMP cognitive assessments were scored using different metrics that combine speed and accuracy, and correlation analyses were run on these metrics and MCCB domains. Of the scoring metrics used, the Rate-Correct Score (RCS) most consistently correlates with baseline MCCB domains corrected for age, gender, and education. Moderate test-retest reliability was observed across certain cognitive assessments such as a mobile version of Trails-Making Test A and Symbol Digit Substitution, which agrees with previous research done by Keefe et al.; poor test-retest reliability, in contrast, was observed across assessments such as Spatial Span. Additionally, we conducted exploratory mediation analyses using sleep data to see if sleep mediates between the Ecological Momentary Assessment (EMA) survey scores and performance on select digital cognitive assessments on mindLAMP. Our results support the initial accessibility, validity and reliability of using smartphones to assess cognition in schizophrenia. Future research to develop additional smartphone-based cognitive tests, as well as with larger samples and in other psychiatric populations, is warranted.