Biological approach to OCD

• the first symptom of OCD is obsessions, this is recurrent unwanted thoughts that are intrusive and cause anxiety
• the second symptom of OCD is anxiety and guilt, this is when the individual fee guilty about their obsessions
• the third symptom of OCD is compulsions, this is when an individual feels the urge to perform specific actions
• to be diagnosed with OCD the individual has to show all three of the symptoms, obsessions, guilt and anxiety and compulsions
• guilt and anxiety are emotional symptoms of OCD
• obsessions are cognitive symptoms of OCD
• compulsions are a behavioural symptom of OCD
• the orbitofrontal cortex detects worrying stimuli and decides on an action to deal with it, once the action has been decided it sends signals to the part of the brain that controls movement
• the basal ganglia monitors the outcome of actions
• the orbitofrontal cortex detects worrying stimuli and decides on an action to deal with it
• The basal ganglia sends inhibitory signals back to the orbitofrontal cortex
• orbitofrontal cortex -> motor cortex -> basal ganglia -> orbitofrontal cortex
• For people with OCD, the signals sent from the basal ganglia to the orbitofrontal cortex are much weaker than usual.
• Those with OCD have impaired communication between the basal ganglia and the orbitofrontal cortex.
• with impaired communication, the orbitofrontal cortex is inhibited less causing it to become hyperactive
• if neurons in the orbitofrontal cortex are hyperactive signals relating to worrying stimuli continue to persist
• When the basal ganglia sends signals to the orbitofrontal cortex, serotonin is released into the orbitofrontal cortex.
• Serotonin acts an inhibitory neurotransmitter in the orbitofrontal cortex.
• support for the neural explanation of OCD comes from case studies, max et al studied a patient with damage to their basal ganglia, study shows that structural damage to the basal ganglia causes OCD
• support for the neural explanation of OCD comes from brain image scanning, research found increased brain activity in the orbitofrontal cortex of adults with OCD​ compared to controls
• a limitation of the neural explanation of OCD is that the results of studies havent always been able to be replicated, this means that results found inconsistent