What is the DSM-V diagnostic criteria for OCD?
- Presence of obsessions, compulsions, or both
- The obsessions or compulsions are time-consuming; cause clinically sig. distress/impairment in social, occupational, or other areas of functioning
- OC symptoms not attributable to physiological effects of a substance or another medical condition
- Disturbance not better explained by symptoms of another mental disorder
What is the DSM-V definition of an obsession?
- Recurrent and persistent thoughts, urges, or images that are experienced, at some time during the disturbance, as intrusive and unwanted cause anxiety or distress
- Attempts to ignore or suppress such thoughts, urges, or images, or to neutralize them with some other thought or action
What is the DSM-V definition of a compulsion?
- Repetitive behaviours or mental acts that the indiv. feels driven to perform in response to an obsession
- Behaviours or mental acts aimed at preventing /reducing anxiety or distress, preventing some dreaded event/situation (excessive)
Give some Examples of OCD:
Harm & Checking
Contamination and washing
Hoarding
What os the prevalence of OCD?
Lifetime: 2.5%
1 year: 1.5-2.1%
What is the usual age of onset?
late teens, early 20’s
Are there any gender differences in the prevalence of OCD?
no
What has OCD been linked with under the obsessive compulsive spectrum disorders?
- Preoccupations/bodily sensations disorders: Body dysmorphic disorder, anorexia, hypochondriasis
- Neurological disorders: Tourette’s syndrome, Autism
- Impulsive Disorders: Kleptomania, Pathologic Gambling
What is OCD most comorbid with?
Major Depressive Disorder
What is the evidence for a Biological Basis of OCD?
- Runs in families
- Often linked to Epilepsy & brain trauma (related to strep infections: autoimmune systems produce antibodies that are hostile toward Caudate nuclei)
- Associated with movement disorders
- Variations in Glutamate, serotonin, white matter genes
- Treatment: drug = first choice, surgery
- Imaging studies: Caudate nuclei
How is strep related to OCD?
autoimmune systems produce antibodies that are hostile toward Caudate nucleus
What is the Neurobiological model of OCD?
- Dysregulation of the caudate nucleus
- Dysfunction in the orbitofrontal-subcortical circuits
- Brain volume changes
where is the caudate nucleus located?
Basal Ganglia
What are the functions of the caudate nucleus?
- involved in memory, procedural learning
- triggers the urge to ‘do something’
- Equivalent of ancient grooming, hoarding and nesting instincts
What brain volume changes take place in patients with OCD?
- Reduced volume of the left anterior cingulate cortecx
- Reduced volume in the left and right orbitofrontal cortex
- Increased volumes of left and right thalamus
4/ Increased grey matter density of frontal subcortical circuits
What is the Behavioral Model of OCD?
Learning aspects:
Ways people attempt to control arousal through avoidance which is difficult to change because it’s negatively reinforced
Give an example of avoidance learning response substitution:
Symbolic undoing
What is symbolic undoing?
- Person has an experience which produces guilt
- They engage in an act that tried to symbolically undo what they feel guilty about
- Act becomes a compulsion
Give an example of symbolic undoing
Washing hands after a “dirty deed”
What are some family factors associated with OCD?
- Highly verbal but not very communicative
- positive evaluation of etiquette
- Social isolation & withdrawal
- Emphasis on cleanliness
- instrumental morality
Give an example of how superstition can result in OCD
example with pigeons being given food randomly, ended up reinforcing whatever behavior they happened to be doing
Trobriand islanders: developed a religion around fishing in the open sea and not around fishing in the lagoon
What is the Cognitive Model of OCD? what model is it complimentary to?
- Over importance of thoughts & need to control thoughts
- Overestimation of threat & lack of tolerance for uncertainty
- Excessive responsibility
- Perfectionism
- Lack of tolerance for emotional discomfort
Complimentary to the Behavioral Model
What are the Treatments for OCD?
SSRIs: problem 40% don’t respond and the remainder attain moderate improvement at best. Frequent relapse when drug is discontinued
Surgery
Exposure and response prevention
What kind of surgery is performed on severe cases of OCD? What is their success rate?
Cingulotomy or Capsuotomy
25-30% experience improvement
