Lecture Two: Obsessive-Compulsive Disorder Flashcards
What is OCD?
Obsessive-Compulsive Disorder
What are obsessions?
Recurrent, intrusive thoughts
What are compulsions?
Actions to reduce anxiety caused by obsessions (e.g. rituals)
Questions about OCD:
- What % of the population has OCD?
- Does it affect women or men more?
- When does OCD start?
- 3%
- Both equally
- Childhood/teen years
Do you need to have both obsessions and compulsions in order to be diagnosed with OCD?
No, you can have just one.
What are the 5 most common broad categories of compulsions?
- Cleaning
- Checking
- Repeating
- Arranging
- Mental Acts (thinking good thoughts)
Is OCD affected by genetics?
Yes! research says genetics can explain between 27%-47% of all OCD cases. In terms of identical twins, if one twin has OCD, 80% of the time the other twin also has OCD.
OCD is a lifespan disorder, what does that mean?
It is chronic and often treatment-resistant
What learning theory can explain why the use of Compulsions is strengthened and repeated?
Operant conditioning, Compulsions are strengthened through negative reinforcement (the absence of something bad happening after doing the compulsion makes the person more likely to do the compulsion again in the future to avoid another negative event)
Name 5 common obsessions:
- Aggressive
- Sexual
- Contamination
- Religious
- Harm, danger, loss or
embarrassment - Superstitious or magical
- Perfectionistic
- Somatic
- Neutral
- “Just-right”
Name 5 common compulsions:
- Checking
- Symmetry/ordering
- Magical/undoing
- Decontamination
- Perfectionistic
- Counting
- Touching or movement
- Somatic
- Mental
- Protective
- Hoarding
What are the two main motivations/drivers of OCD?
Give an explanation of what both mean.
§ Harm avoidance
– Anxious apprehension, worrying and a desire to prevent potential harm
§ Incompleteness
– An inner sense of imperfection leading to the repetition of certain actions
or behaviours until the action or perfection conforms to “absolute, yet
often inarticulable, subjective standards”. Often a sensory sense of “not just-right”
What is the definition of Harm Avoidance?
The tendency to respond intensely to signals of aversive stimuli, which causes the inhibition of behaviours leading to punishment, novelty, or frustration
What part of the brain is thought to be involved in Harm Avoidance traits?
The Amygdala
How is the Incompleteness drive experienced?
Experienced as distress secondary to a disturbance in any sensory or cognitive modality: a subjective experience of things being “not just right”
Which of the two drives for OCD is most common?
Incompleteness
What is the biological/neuropsychological explanation behind the Incompleteness drive?
- Related to a deficit in the ability to use cognitive, affective or sensory feedback to guide behaviour
- Failure in stop-signal processes
- Persistent error signals inappropriately prompt ongoing corrective action
What are the 4 domains of incompleteness?
– Goal-directed: prioritising, starting, stopping and completing actions
– Perfectionism
– Tic-like sensory experiences: symmetry
– Sensory phenomena: sounding, feeling or looking right
Abnormalities in what brain structure are linked to the Incompleteness drive of OCD?
Abnormalities in the frontal-striatal circuit
What are the 5 less common drivers of OCD?
- Disgust sensitivity: Revulsion towards potential contamination
- Intolerance: Avoiding/limiting sensations or internal experiences that may cause discomfort. Intolerance of uncertainty
- Perfectionism: Excessively high standards of performance, along with belief that
mistakes are not acceptable - Variable insight: Degree to which an individual recognises the irrationality or
disproportionate nature of their symptoms (Varies substantially in OCD) - Pathological responsibility: Any responsibility over an outcome = full responsibility for that outcome
What are 3 neuropsychological facts surrounding OCD?
Individuals with OCD have:
- Inability to inhibit prepotent responses (e.g. stop/signal task)
- Difficulty responding flexibly/switching and preservation (e.g. reversal-learning task, set-shifting)
- Reliance on habitual instead of goal-oriented responding
What 3 neurotransmitter dysfunctions can be involved in OCD?
Serotonin dysfunction
Dopamine dysfunction
Glutamate dysfunction
What percentage of OCD patients respond to pharmacotherapy? (specifically for drugs that increase serotonin)
40-60%
What are the 3 areas of the brain that show differences in structure and function in OCD individuals? (compared to non-OCD)
- Anterior Cingulate Cortex
- Orbitofrontal Cortex
- Striatum (nucleus Accumbens, caudate, putamen)
What functions do neural circuits in behaviour control/involve?
- Motor
- Cognitive
- Affective
- Motivational processes
What cognitive processes are thought to be impaired in individuals with OCD? (4)
- Learning
- Habit formation
- Goal-directed behaviour
- Emotional processing
Abnormalities in what neural circuitry are thought to underlie OCD?
Abnormalities in frontostriatal circuitry
Where is the orbitofrontal cortex, and what does it do?
The base of the front third of the brain, present in both hemispheres. Is responsible for flexibility (an adaptation of behaviour/cognitive strategies after positive or negative feedback)
How is the OFC (orbitofrontal cortex) linked to OCD? (3 trends seen in research findings)
- Decrease OFC volume in OCD
- Increased OFC symptom-related activity (impaired flexibility)
- Defective OFC recruitment during reversal learning tasks
What is the mOFC (medial OFC) and lOFC (lateral OFC) responsible for?
mOFC = reward processing lOFC = punishment processing
What important process is the Dorsal Striatum involved in?
Habit Formation
What important process is the Ventral Striatum involved in?
Reward Processing
Hyperactivation of the dorsal striatum (caudate and putamen) causes what? (seen in many OCD patients)
- Impaired/lowered goal-directed control over behaviour
- Excessive habit formation
What does excessive habit learning lead to?
The development of automatic, inflexible behaviours that are performed regardless of their consequences
What is a key reward of behaviour (as seen in fMRIs) to people with OCD?
Successful avoidance
What is avoidance learning?
when the safety produced by the behaviour becomes rewarding and so the avoidance behaviour is reinforced
The OFC of OCD patients can be seen to activate for 2 main outcomes/events, what are they?
- Avoidance of an aversive outcome
- Receiving a reward
Individuals with OCD have less or more neural activity in response to reward anticipation than control participants?
Less
What is the most common treatment combination for individuals with OCD?
CBT (cognitive behavioural therapy) or/and EXRP (exposure and response prevention therapy), and SSRI (selective serotonin reuptake inhibitor) medication.
What is exposure and response prevention (EXRP) therapy?
Where individuals confront their fear, inhibit performing their normal response, realise that there is no aversive consequence even without OCD behaviour. Therapist aided.
What is acceptance and commitment therapy?
It teaches individuals to observe and accept the unpleasant stimulus/experiences without resorting to rituals. Less supported than EXRP.
What is the only proven first-line medication for OCD treatment? What percentage of patients prove to be responsive?
Serotonin reuptake inhibitors, 65%
How can the effects of SRI medication be increased? (what other treatments can be added) (3)
- CBT
- Antipsychotic medication (beware side effects)
- Drugs that affect the glutamatergic system
What invasive and non-invasive procedures can be performed to help individuals with OCD? (3)
Non-Invasive:
- Transcranial magnetic stimulation (effects of one session last 8 hours)
Invasive:
- Ablative lesions in CSTC (cortico-striatal-thalamic-cortical)
- Deep brain stimulation
What are some OCD related disorders? (4)
- Body dysmorphic disorder
- Trichotillomania
- Excoriation
- Hoarding
What is body dysmorphic disorder?
Distressing preoccupation with an imagined or slight defect in appearance.
40% spend 3-8 hours per day thinking about appearance, 25% spend 8+ hours
36-39% of patients show issues with Delusions of reference (e.g. think that people across the room are laughing at them when they are laughing at a cat video)
Shows compulsive behaviours like excessively checking mirrors, and seeking reassurance from friends.
What is Trichotillomania?
Hair-pulling disorder. Mostly affects females and often begins at 10-13 yrs old. occurs in 0.5-2% of the population. Triggers include: sensory, emotional and cognitive
What is Excoriation?
Skin picking disorder. Typically begins due to a dermatological condition. Present in 1.4-5.4% of the population. Triggers include: stress, anxiety, downtime.
What are the key features of Hoarding Disorder?
- Excessive acquisition of items (often those with little to no value)
- Often lack insight
- Persistent
- Distress and/or impairment
- 2.3% of population
- Age of onset = 20-30
More than what % of OCD patients also meet the criteria for comorbid anxiety or mood disorder?
More than 50%
Why do individuals with OCD experience such a high rate of comorbidity?
- OCD shares several underlying personality traits
- also shares several underlying neurobiological and cognitive abnormalities
How is exposure to trauma linked to OCD?
- Trauma has been associated with onset of OCD
- OCD caused by trauma has more severe outcomes and is more difficult to treat
What eating disorders are commonly comorbid with OCD? (3)
- Anorexia Nervosa (75%)
- Bulimia Nervosa
- Binge Eating Disorder
What are the two major parallels between OCD and eating disorders?
- Intrusive thoughts
- Repetitive behaviours
