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Presented on the symposium entitled “Envisioning the Clinical Integration of Network Analysis and CBT: New Developments.” McNally, R. J. (Chair). Association of Behavioral and Cognitive Therapies. October, 2016. New York, NY.
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Presented on the symposium entitled “Envisioning the Clinical Integration of Network Analysis and CBT: New Developments.” McNally, R. J. (Chair). Association of Behavioral and Cognitive Therapies. October, 2016. New York, NY. Comorbid Obsessive-Compulsive Disorder and Depression:A Network Analytic Approach Richard J. McNally Patrick Mair Harvard University Beth L. Mugno Bradley C. Riemann Rogers Memorial Hospital
Comorbidity • As many as two-thirds of people with OCD develop major depression • OCD usually precedes onset of depression • Successful behavior therapy for OCD often reduces depression when overall severity is moderate
Traditional View of Comorbidity (Cramer et al., 2010, Behavioral & Brain Sciences)
Network View of Psychiatric Comorbidity(Cramer et al., 2010, Behavioral & Brain Sciences)
Method • Subjects • 408 patients with primary OCD • Rogers Memorial Hospital • Assessed at intake • Yale-Brown Obsessive Compulsive Scale (Y-BOCS) • 10 items (0 – 4) • Quick Inventory of Depression Symptomatology –Self-Report (QIDS-SR 16) • 16 items (0 -3)
Bayesian Network • A Bayesian network analysis returns a directed acyclic graph (DAG) • The “hill climbing” algorithm tests for conditional independence relations among nodes
Averaged Bayesian Network • 1000 iterations of the network (“bootstrapping samples”) • An edge remains only if its appears in at least 85% of the iterations • The direction of an edge? • X > Y percentage • Y > X percentage
Averaged Bayesian Network • The “importance” of an edge • BIC value (Bayesian Information Criterion) • The larger the absolute magnitude, the more “damaging” to model fit if one were to remove the edge from the network
Unresolved Issues • Candidate causal system? • No important unmeasured variables? • Are DAGs clinically plausible?
Additional slides that time limits prohibited me from presenting on the NYC ABCT symposium.
Graphical LASSO • Least Absolute Shrinkage and Selection Operator • Edges are partial correlations • Computed via “regularization” • Small edges driven to zero • Likely “false alarms” vanish from the graph • Undirected network
1000 bootstrap samples • Estimate the robustness of the edges • Estimate the robustness of the centrality metrics