Obsessive-Compulsive Disorder (OCD)
Pathophysiology
Involves complex interactions between brain circuits
Neurotransmitters
Serotonin (5-HT):
Reduced serotonin signaling is a significant factor in OCD.
Dysregulation affects mood, anxiety, and inhibitory control.
SSRIs (Selective Serotonin Reuptake Inhibitors) help restore serotonin balance.
Dopamine:
Altered dopamine activity may influence compulsive behaviors and habit formation.
Hyperactivity in the striatum exacerbates compulsions.
Glutamate:
Emerging research implicates glutamate in OCD, suggesting excitatory-inhibitory imbalances in neural circuits.
Genetic
Family studies indicate a heritability rate of 45-65% in first-degree relatives.
Variants in genes regulating serotonin (e.g., SLC6A4), glutamate, and dopamine pathways have been implicated.
Environmental factors
Epigenetics:
Environmental stressors, infections (e.g., PANDAS syndrome), and trauma may modify gene expression and contribute to OCD development.
PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections):
In some cases, OCD is triggered by autoimmune responses following streptococcal infections.
Inflammatory processes may alter brain function in susceptible individuals.
Neuroinflammation:
Elevated cytokines and inflammatory markers in OCD patients suggest a possible role of immune dysregulation.
Brain Circuitry Dysfunction
Associated with hyperactivity in specific brain regions,
Cortico-striato-thalamo-cortical (CSTC)
Key Brain Regions:
Orbitofrontal Cortex (OFC):
Involved in decision-making and evaluating rewards.
Overactivity in the OFC contributes to excessive worry and intrusive thoughts.
Anterior Cingulate Cortex (ACC):
Associated with error detection and emotional regulation.
Dysregulation leads to heightened awareness of perceived "errors."
Basal Ganglia:
Includes structures like the striatum.
Plays a role in the initiation and control of movements and habits.
Dysfunction contributes to compulsive behaviors.
Thalamus:
Acts as a relay station, filtering sensory information.
Hyperactivity in this region reinforces obsessive thoughts and behaviors.
Behaviors
Obsessions:
Intrusive thoughts
Fear of contamination
Doubts about safety (e.g., leaving doors unlocked)
Unwanted sexual or aggressive thoughts
Compulsions:
Excessive cleaning/washing
Repeated checking
Counting or repeating actions
Arranging items until “just right”
Causes & Risk Factors:
Genetic predisposition
Brain structure and functioning (e.g., overactivity in certain neural pathways)
Environmental factors (e.g., traumatic events)
Family history of anxiety disorders
Associated Disorders:
Body Dysmorphic Disorder
Hoarding Disorder
Trichotillomania (hair-pulling)
Excoriation (skin-picking)
Long-Term Outcomes:
Importance of early intervention
Role of ongoing therapy
Building resilience through coping strategies
Preventing relapse with consistent follow-up care
Treatment Approaches:
Cognitive-Behavioral Therapy (CBT), particularly Exposure and Response Prevention (ERP)
Medication (e.g., selective serotonin reuptake inhibitors or SSRIs)
Support groups and peer support
Lifestyle changes: stress management, mindfulness, exercise
Emotional Impact:
Anxiety and distress
Feelings of shame or embarrassment
Social withdrawal
Depression