David Barlow is best known for his pioneering work in the treatment of anxiety and related emotional disorders. He developed groundbreaking exposure-based treatments for agoraphobia and panic disorder, and later created the Unified Protocol (UP), a transdiagnostic cognitive-behavioral therapy that treats the underlying emotional processes shared across anxiety, depression, and other disorders. He is also the author of the widely used textbook 'Abnormal Psychology: An Integrative Approach' and the definitive reference 'Anxiety and Its Disorders'. A professor emeritus at Boston University, he has published over 650 articles and 90 books.

The Unified Protocol (UP) is a transdiagnostic cognitive-behavioral treatment developed by David Barlow and colleagues at Boston University. Instead of targeting specific diagnoses like panic disorder or major depression, the UP focuses on core emotional processes—such as neuroticism, avoidance, and emotion dysregulation—that underlie all emotional disorders. The protocol teaches patients skills in mindfulness, cognitive flexibility, and emotion exposure. It has been shown to be effective across anxiety, depression, eating disorders, substance use, and other conditions, making it a versatile, evidence-based alternative to disorder-specific manuals.

Barlow's research reframed anxiety as a disorder of emotion, emphasizing the role of neuroticism and avoidance in maintaining psychopathology. He developed the Anxiety Disorders Interview Schedule (ADIS), a gold-standard diagnostic tool for differential diagnosis among anxiety and mood disorders. His early work on the treatment of agoraphobia and panic laid the foundation for modern exposure-based therapies. He also challenged traditional diagnostic boundaries by demonstrating that anxiety, mood, and related disorders share common vulnerabilities and treatment targets, paving the way for transdiagnostic approaches that are now widely adopted in clinical practice.

David Barlow has authored or edited numerous landmark works. 'Anxiety and Its Disorders: The Nature and Treatment of Anxiety and Panic' (1988, 2nd ed. 2002) is a foundational text in the field. 'Abnormal Psychology: An Integrative Approach', co-authored with V. Mark Durand, is one of the most widely used abnormal psychology textbooks. He also edited the 'Clinical Handbook of Psychological Disorders' and the 'Oxford Handbook of Clinical Psychology'. His 'Unified Protocol for Transdiagnostic Treatment of Emotional Disorders' (Therapist Guide and Client Workbook) has become a standard resource for clinicians. His works have been translated into over 20 languages.

While Barlow is not the originator of the diathesis-stress model, his work on the Unified Protocol and the role of neuroticism in emotional disorders is deeply aligned with its principles. He emphasizes that individuals vary in their underlying temperament or vulnerability (diathesis), such as neuroticism, which, when combined with life stressors, can precipitate emotional disorders. His transdiagnostic approach targets this shared vulnerability rather than just surface symptoms, effectively addressing the stress-diathesis interaction by teaching patients to manage their emotional reactivity and avoidant coping. His integrative model thus provides a modern, evidence-based instantiation of the diathesis-stress framework.

David Barlow received his PhD from the University of Vermont in 1969. He has held professorships at the University of Mississippi Medical Center, Brown University, and the University at Albany. He joined Boston University in 1996, where he is now Professor of Psychology and Psychiatry Emeritus and Founder and Director Emeritus of the Center for Anxiety and Related Disorders (CARD). He has been continuously funded by the National Institutes of Health for over 40 years. He is a past-president of the APA's Division of Clinical Psychology and the Association for Behavioral and Cognitive Therapies, and served on the DSM-IV Task Force.

David Barlow has received numerous prestigious awards. He is a recipient of the Distinguished Scientific Award for Applications of Psychology from the American Psychological Association and the James McKeen Cattell Fellow Award from the Association for Psychological Science, which honors a lifetime of significant intellectual achievements in applied psychological research. He has also been recognized with the Award for Distinguished Contribution to Clinical Psychology from the Society of Clinical Psychology (APA Division 12) and the Lifetime Achievement Award from the Association for Behavioral and Cognitive Therapies. In 2015, he received an honorary degree from his alma mater, the University of Vermont.

David Barlow served as a member of the DSM-IV Task Force of the American Psychiatric Association and was a Co-Chair of the Work Group for revising the anxiety disorder categories. His research on the nature of anxiety and the overlap among emotional disorders directly informed the conceptualization and criteria for anxiety disorders in DSM-IV and subsequent editions. His empirical work demonstrating that anxiety and mood disorders share common temperamental and cognitive features contributed to the reclassification of disorders in DSM-5, including the separation of obsessive-compulsive and trauma-related disorders into distinct chapters. His ongoing advocacy for a dimensional, transdiagnostic approach continues to shape debates about the future of psychiatric nosology.