Biological EXPLAINATIONS of OCD

Question 1

Concordance rate

Answer 1

Measure of genetic similarity
E.g. Mz twins have high concordance rate

Question 2

Dopamine

Answer 2

Motivation, drive

Question 3

Gene

Answer 3

Part of chromosome, carries DNA

Question 4

Neurotransmitter

Answer 4

Chemicals in brain, part of NS, transmits nerve impulses across synapse

Question 5

Serotonin

Answer 5

Mood regulation

Question 6

Lewis 1936

Answer 6

37% OCD has OCD parents> vunerability inherited

Question 7

Nestadt 2010

Answer 7

MZ OCD concordance= 68%
DZ = 31%

Question 8

COMT gene

Answer 8

• regulates dopamine
• common in OCD patients
• lower levels of activity in COMT gene- higher levels of dopamine

Question 9

SERT gene

Answer 9

• transportation of seretonin
• low seretonin in OCD
• Ozaki- mutation of SERT gene in 2 families > 6/7 members had OCD

Question 10

Dopamine

Answer 10

Abmornal level associated w OCD

Question 11

Seretonin

Answer 11

• low seretonin= depression
• antidepressants (SSRI) reduces OCD symptoms

Question 12

Diathesis- stress model

Answer 12

Genes give vunerability> environmental trigger needed

Question 13

Orbitofrontal cortex and worry circuit

Answer 13

OFC converts sensory input to thoughts –> BG Claudette nucleaus supresses signals to OFC –> OFC sends signals to thalamus about worries –> DAMAGED CN fails to supress signals from OFC –> thalamus alerted sends rep signals to OFC (compulsions)