Performance of active and passive ambulatory assessment measures and mood monitoring in depression: a systematic review

<ns3:p>Background Ambulatory assessment and mood monitoring offer a promising, flexible, and efficient approach for assessing mood, mental state, and behaviour, potentially improving on traditional clinical outcome measures. However, the real-world utility of these novel technologies fundamentally depends on their demonstrated performance. Aims This systematic review aimed to assess the performance and validity of active and passive ambulatory assessment and mood monitoring outcome measures in randomised and non-randomised studies in depression over 3 months or longer, evaluating their performance against established clinical measures and through inter-ambulatory assessment comparisons. Methods Systematic review of performance of ambulatory assessment and mood monitoring protocols in RCTs and non-randomised studies in depression (PROSPERO: CRD42023396473). Studies were identified and rated for risk of bias. We were not able to pool performance data to calculate effect sizes so we were unable to complete meta-analysis. Results 35 studies including 9310 participants used 28 different ambulatory assessment/mood tracking procedures and included 436 performance metrics. There was large inconsistency and heterogeneity in these reported metrics which prevented robust comparison and definitive inferences around performance. Active ambulatory assessment measures demonstrated stronger correlation coefficients than passive ambulatory assessment when compared to established measures. Aggregate passive ambulatory assessment measures may perform better than single item measures. Most studies had low-moderate risk of bias. Conclusions Despite ambulatory assessment’s promise, our findings indicate a critical knowledge gap: it remains unclear whether passive ambulatory assessment approaches have sufficient performance to provide a less subjective method of mood measurement. The reported methodological heterogeneity across studies, particularly in measurement and reporting of performance metrics prevents robust comparison and replication of findings. Increased standardization in ambulatory assessment methodology and reporting is needed to enable reliable assessment and widespread implementation of these novel behavioural measures.</ns3:p>