OCD

Question 1

Obsessions

Answer 1

Recurrent, persistent thoughts, urges, or images experienced as intrusive or unwanted.

Question 2

Compulsions

Answer 2

Repetitive behaviors or mental acts that a person feels driven to perform in response to an obsession. Unrealistic or excessive. Aimed at preventing or reducing distress.

Question 3

Prevalence of OCD

Answer 3

2-3%, >50% onset in childhood.

Question 4

Etiologic hypotheses of OCD

Answer 4

Neurotransmitter based: serotonin/glutamate

Circuit based: Cortico-striato-thalamo-cortical loops

Question 5

Is OCD heritable?

Answer 5

Yes, some genetic contribution

Question 6

Serotonin hypothesis

Answer 6

Based on the fact that SSRIs are useful in OCD

Question 7

Glutamatergic hypothesis

Answer 7

Association with a particular glutamate transporter gene. Increased CSF glutamate

Question 8

Evidence for circuit based pathology

Answer 8

fMRI studies show increased brain activity in the orbitofrontal cortex, ACC, and caudate in patients with OCD. These normalize with successful treatment. Insular involvement generally signals disgust. Circuitry is reinforced and causes habit forming.

Question 9

Animal models of OCD

Answer 9

Show repetitive grooming behavior (SAPAP3 KO, have anxiety-like traits)

Question 10

Mainstays of treatment for OCD

Answer 10

SSRIs or SRIs, other classes of antidepressants are ineffective.
Cognitive behavioral therapy (very effective)
DBS - if other treatments not effective
Ablative neurosurgery (not preferred)

Question 11

Does OCD resolve?

Answer 11

Not usually.

Question 12

What is the target of ablative surgery for OCD?

Answer 12

Anterior capsulotomy or anterior cingulotomy.

Question 13

Category of OCD in DSM-V?

Answer 13

With other repetitive disorders, not with other anxiety disorders anymore.