Focus on alcohol & drug abuse: improving service delivery for individuals with co-occurring disorders: new perspectives on the quadrant model.

This column summarizes findings of a study that examined the usefulness of the quadrant model for improving service delivery for persons with co-occurring disorders. The authors discuss treatment recommendations, goals and barriers related to delivering care, policy recommendations for implementing evidence-based interventions, and strengths and limitations of the model. They conclude that although the quadrant model is useful for conceptualizing systems-level factors for improving delivery, its further development is unlikely to result in improved care at the clinical level. They call for research to develop and implement evidence-based practices targeted to specific populations of persons with co-occurring disorders.