The eco-affective health assessment protocol: a standardized multimodal instrument battery for measuring affective, cognitive, and functional responses to environmental change.

The field of eco-affective health has produced a growing body of evidence linking environmental change to human psychological and cognitive functioning, but it has done so without a shared methodological foundation. Studies of solastalgia, eco-anxiety, environmental risk perception, and adaptive decision-making use incompatible instruments, inconsistent scoring procedures, and divergent operationalizations of the same constructs, limiting cumulative knowledge, cross-study comparison, and translation into policy-relevant surveillance. This Methods paper introduces the Eco-Affective Health Assessment Protocol (EAHAP): a standardized, multimodal, and modular instrument battery designed to measure affective, cognitive, and functional responses to environmental change in a coherent and replicable framework. The EAHAP organizes existing instruments, the large majority independently validated, with one adapted ecological grief measure explicitly flagged as a candidate instrument pending independent psychometric validation, into three interdependent domains. The eco-affective domain covers solastalgia, eco-anxiety, ecological grief, affective numbing, and place attachment. The cognitive domain covers environmental risk perception, attentional processing, environmental appraisal, and adaptive decision-making under ecological stress. The functional domain covers psychological distress, anxiety and depressive symptoms, sleep disruption, and daily functioning limitation. Each domain is theoretically positioned within the Eco-Affective Health framework as a distinct signal layer, with eco-affective states functioning as early-warning indicators, cognitive mediators explaining variability in response to identical exposures, and functional outcomes providing downstream validation and economic relevance. The paper provides a complete description of materials and instruments, a step-by-step implementation protocol with timing and decision rules, a module selection matrix for different study types, anticipated results with expected psychometric properties, and a troubleshooting guide for the most common pitfalls. Cultural adaptation procedures are specified as a mandatory component of all implementations. The EAHAP is designed to be modular, allowing domain-specific use in fundamental research, and fully integrated for epidemiological surveillance, early warning systems, and intervention evaluation. By providing a shared methodological infrastructure, the EAHAP aims to accelerate the development of eco-affective health as a cumulative, cross-contextual, and policy-relevant scientific field.