The GALENOS Upper-Level Mental Health Ontology: Enabling evidence synthesis by representing the domain of mental health and associated interventions

<ns3:p> Background Synthesising mental health evidence is challenging due to fragmentation of the field, a high volume of publications and inconsistent terminology being used. Without a better overview of the evidence, developing evidence-based interventions to improve mental health is challenging. The Global Alliance for Living Evidence on aNxiety, depressiOn and pSychosis (GALENOS) addresses these challenges by synthesising and regularly updating evidence through living systematic reviews on anxiety, depression and psychosis. This project is developing a precise classification framework, an ontology, to organise the evidence from these reviews in a data repository. This paper presents the ontology’s upper-level structure, which specifies, defines and links the classes that will organise the data identified in systematic reviews into a shared framework with a common language. Methods The development of the upper-level ontology followed five steps: (1) specifying the ontology’s scope; (2) drafting classes and relationships by reusing parts of existing ontologies and creating new classes where necessary; (3) performing a stakeholder consultation incorporating feedback from mental health experts and people with lived experience; (4) specifying relationships between classes; and (5) making the ontology machine readable and publishing it online. Results The ontology’s upper level includes 25 key classes covering research studies, human populations (including population history, persons and their personal histories), mental health interventions (encompassing both content and delivery) and intervention scenarios, which represent that interventions are delivered in specific contexts with varying plans, outcomes, mechanisms of action and levels of participant engagement. The classes are connected by nine relationship types such as <ns3:italic>participates_in</ns3:italic> and <ns3:italic>has_part.</ns3:italic> Conclusion The upper-level ontology provides a structured framework to represent key aspects of mental health and mental health interventions, supporting linking data and integrating evidence. It also lays the basis for a more elaborated ontology of mental health and interventions. </ns3:p>