Anxiety, Obsessive-Compulsive, and Trauma-Related Disorders
This area groups the psychiatric conditions in which pathological fear, anxiety, obsessions and compulsions, or reactions to trauma are the central feature. It spans the classic anxiety disorders (such as generalized anxiety disorder and panic disorder), obsessive-compulsive disorder, and post-traumatic stress disorder, together with the psychological and behavioral interventions used across these conditions. As a reference-educational overview, it orients the reader to shared mechanisms and to the distinct clinical entities catalogued in the topics below.
Definition
A grouping of psychiatric disorders characterized by excessive or persistent fear and anxiety, intrusive obsessions with repetitive compulsions, or maladaptive responses to traumatic and stressful events, with associated distress and functional impairment.
Scope
The area covers the phenomenology, epidemiology, mechanisms, and evidence base of fear-, anxiety-, obsession-, and trauma-related disorders as defined in contemporary classifications. In DSM-5/DSM-5-TR these are organized into three adjacent chapters - Anxiety Disorders, Obsessive-Compulsive and Related Disorders, and Trauma- and Stressor-Related Disorders - which this area treats together because of their overlapping symptomatology, comorbidity, and shared treatment principles. It does not provide diagnostic or treatment instructions for individuals.
Sub-topics
Core questions
- What distinguishes normal, adaptive fear and anxiety from a clinical disorder?
- How do anxiety, obsessive-compulsive, and trauma-related disorders overlap and differ in mechanism and presentation?
- What learning, neurobiological, and cognitive processes underlie these conditions?
- What is the evidence base for psychotherapeutic and pharmacological interventions across this group?
Key concepts
- Fear, anxiety, and avoidance
- Obsessions and compulsions
- Trauma exposure and re-experiencing
- Comorbidity and shared vulnerability
- Exposure-based therapy
- Serotonergic pharmacotherapy
Key theories
- Fear conditioning and extinction learning
- Associative learning models hold that fear can become attached to previously neutral cues and contexts, and that recovery often depends on new extinction learning rather than erasure of the original memory; impaired extinction is a candidate mechanism shared across anxiety and trauma-related disorders.
Mechanisms
Across these disorders, normal fear and anxiety systems become dysregulated. Conditioning and avoidance learning can entrench maladaptive responses, while deficits in extinction learning and emotion regulation help maintain them; cortico-limbic circuits including the amygdala and prefrontal cortex are repeatedly implicated, and serotonergic signalling is a shared pharmacological target. The specific topics describe how these general processes take disorder-specific forms - chronic apprehension in generalized anxiety disorder, recurrent panic and interoceptive fear in panic disorder, obsessions and neutralizing compulsions in obsessive-compulsive disorder, and trauma-cued re-experiencing in post-traumatic stress disorder.
Clinical relevance
These are among the most common psychiatric presentations in primary and specialty care, and they frequently co-occur with one another and with depression. The area is intended to help readers understand how the conditions are defined, distinguished, and studied; it characterizes evidence and mechanisms rather than prescribing diagnosis or treatment for any individual.
Epidemiology
Anxiety disorders as a group are among the most prevalent mental disorders worldwide, with high lifetime and 12-month prevalence and typically early onset; the National Comorbidity Survey Replication documented their high frequency and extensive comorbidity in the U.S. population. Obsessive-compulsive disorder and post-traumatic stress disorder are less common but carry substantial chronicity and disability.
Evidence & guidelines
Cognitive behavioral therapy, particularly exposure-based methods, and serotonergic medication (SSRIs/SNRIs) have the strongest evidence base across this group; meta-analyses of CBT for anxiety and related disorders show robust effects relative to placebo. Major classifications (DSM-5-TR, ICD-11) define the constituent entities, and disorder-specific guidelines exist for each topic.
History
The grouping reflects a long evolution in how fear-related psychopathology has been classified. Earlier nosologies treated obsessive-compulsive disorder and trauma reactions as anxiety disorders; DSM-5 (2013) reorganized them into adjacent but distinct chapters - Anxiety Disorders, Obsessive-Compulsive and Related Disorders, and Trauma- and Stressor-Related Disorders - recognizing both their kinship and their differences. This area follows that contemporary structure.
Debates
- How sharply should obsessive-compulsive and trauma-related disorders be separated from the anxiety disorders?
- DSM-5 split these conditions into separate chapters on grounds of distinct mechanisms and treatment response, but the disorders share fear circuitry, frequent comorbidity, and overlapping interventions, and the optimal boundaries remain debated.
Key figures
- Michelle Craske
- Murray Stein
- Edna Foa
- David Clark
- Ronald Kessler
Related topics
Seminal works
- kessler-2005
- craske-2017
- penninx-2021
Frequently asked questions
- Why are obsessive-compulsive disorder and PTSD grouped with anxiety disorders here?
- They share dysregulated fear and anxiety systems, frequent comorbidity, and overlapping treatments. In DSM-5-TR they sit in three adjacent chapters, and this reference area treats them together while keeping each as a distinct topic.
- What treatments work across these disorders?
- Exposure-based cognitive behavioral therapy and serotonergic medications (SSRIs/SNRIs) have the broadest evidence base, though the specific protocol differs by disorder. This entry summarizes evidence and does not offer individual treatment advice.