Another example of clinical relevance of ENIGMA‐OCD is the potential for discovering prognostic biomarkers, that is, the prediction of treatment response based on morphometric and/or functional brain signatures. For instance, response to cognitive behavior therapy (CBT) has been linked to structural variability in the prefrontal cortex (Fullana et al., 2014; Hoexter et al., 2013) and activation and connectivity of the amygdala (Fullana et al., 2017; Göttlich, Krämer, Kordon, Hohagen, & Zurowski, 2015; Olatunji et al., 2014). Prediction studies have been so far limited in sample size and therefore replicability of findings has been poor. We have now started using data from ENIGMA‐OCD samples with longitudinal clinical data of 170 children with OCD (from nine sites) and 315 adults with OCD (from seven sites), to study how variation in morphological values (cortical thickness, surface area, and subcortical volumetry) is related to variation in treatment response (Bertolin, Martinez‐Zalacain, Boedhoe, & Alonso, 2019). Moreover, we expect that multimodal imaging approaches, combining data on morphological features with measurements of white matter integrity and information on network function using resting‐state fMRI, will be more informative for predicting treatment response at the individual level using machine learning analyses.
