Multimodal Cohort Study of Generalized Anxiety Disorder (MC-GAD)

Generalized anxiety disorder (GAD) is a heterogeneous psychiatric disorder with substantial variation in clinical presentation, treatment response, disease course, and risk of recurrence. Current diagnosis and clinical management are mainly based on clinical interviews and symptom assessments, while objective markers that can assist in diagnosis, assessment of disease severity, and prediction of long-term outcomes remain limited. This prospective cohort study is designed to characterize the longitudinal course of GAD and to integrate clinical and biological information collected over time.

Participants enrolled in the cohort will receive treatment according to routine clinical practice rather than being assigned to a specific intervention by the study protocol. Information on current treatments, including pharmacological, psychological, and physical treatments, will be recorded during follow-up. Changes in anxiety symptoms, associated symptoms, treatment response, adverse events, and other clinical characteristics will be assessed longitudinally. The study will examine patterns of symptom change and identify factors associated with persistence, recurrence, treatment response, and prognosis.

A multimodal data collection framework will be used to characterize GAD from complementary clinical and biological perspectives. In addition to demographic, clinical, medical, treatment, and family-history information, the study will collect blood samples and multiple types of brain-related data. These include electroencephalography, magnetic resonance imaging, magnetoencephalography, and functional near-infrared spectroscopy. Computerized neuropsychological assessments will be used to evaluate cognitive domains such as executive function, decision-making, reward processing, and emotion recognition. Dynamic information such as heart rate variability, sleep patterns, and changes in emotional state will also be collected.

Participants will undergo repeated follow-up assessments after baseline. Follow-up visits are scheduled at weeks 2, 4, 8, 12, 24, 36, and 48, followed by an additional one-year extended follow-up. At these visits, researchers will assess changes in symptoms and current treatment, record adverse events, and collect selected clinical, blood, electrophysiological, neuroimaging, neuropsychological, and real-time health data according to the study schedule.

By integrating longitudinal clinical information with multimodal biological data, this study aims to characterize the clinical course of GAD, explore potential objective biomarkers, identify factors associated with treatment response and prognosis, and develop models for individualized outcome prediction. The resulting longitudinal database is expected to provide a foundation for risk stratification and more individualized approaches to the diagnosis, treatment, and long-term management of GAD.