Lec 39 Obsessive Compulsive Disorder Flashcards
How is OCD classified?
in DSM-5 classified with obsessive-compulsive & related disorders
b/c repetitive behaviors = distinguishing feature
What are the two main categories of symptoms for OCD?
obsessions and compulsions
What are compulsions?
- repetitive behaviors or mental acts that person feels driven to do in response to obsession or according to rules that must be rigidly applied
- aimed at preventing or reducing distress or preventing dreaded event or situation that they are not realistically connected to
- unrealistic or excessive
- behaviors not inherently gratifying or pleasurable
What are obsessions?
- recurrent, persistent thoughts, urges, images experienced as intrusive and unwanted
- attempts to ignore, suppress, or neutralize with another thought or action
- person knows its his/her own thoughts
What are some typical compulsive behaviors?
- cleaning/washing
- ordering/arranging
- repeating
- checking
- counting
- hoarding/collecting
What are some typical concerns of obsessive behavior?
- contamination
- safety/harm
- religion
- need for symmetry
- aggression
- sex
- somatic fears
What is diagnostic criteria of OCD?
- presence of obsession of compulsion
- insight; acts acknowledged as senseless or excessive at some point during illness
- obsessions/compulsions produce distress, are time consuming (>1 hr /day) or interfere with function
What is the learning theory model of OCD etiology?
- compulsions are a conditioned response that reduce anxiety
- self-reinforced by bringing relief from obsessions
- supported by proven efficacy of cognitive-behavior therapy [CBT]
What is the basis of serotonin biological theory of OCD etiology?
- due to neurotransmitter imbalance
serotonin: evidence is based on efficacy of SSRI in treatment of OCD
What is the circuit-based theory of OCD etiology?
- hyperactivity of cortico-striatal-thalamo-cortical [CSTC] circuits involving basal ganglia, thalamus, anterior limb IC, orbitofrontal cortex
- functional brain imaging studies show increase brain activity in these areas with OCD
- abnormalities normalize during treatment of OC symptoms
- hyperactivity could be caused by excess tone in direct relative to indirect OFC-subcortical path
–> OCD involves imbalance between direct and indirect paths leading to relatively greater excitation of the direct circuit and resultant stereotyped behavior
What is prevalence and course of OCD?
- lifetime prevalence 2-3%
- onset occurs in childhood in more than 50%
- usually chronic
- equal number women + men
What is tourette’s?
- disorder in which affected individual has motor and vocal tics many times a day nearly every day for at least 1 year
- onset before age 18 yrs
- significant comorbidity TS and OCD likely due to shared genetic factors + basal ganglia
What is the likely cause of OCD?
- combination neurobiologic, genetic, behavioral, cognitive, environmental factors
What is the evidence for NT glutamate biological theory of OCD etiology ?
neurotransmitter imbalance
association between OCD and SLC1A1 = glutamate transporter gene
- increased caudate glutamate
- elevated CSF glutamate
- trials of medications that block glutamate receptor and have shown benefits for OCD
How is the infection-triggered autoimmune process associated with OCD?
PANDAS = pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections
- rare disease in children
- causes rapid onset OCD symptoms and/or tic disorders
- autoimmune rxn to strep infection produces antibodies that interfere with basal ganglia function
