4.8 The biological approach to treating OCD

Question 1

how do we treat OCD?

Answer 1

Antidepressants:
SSRI drugs (e.g. Prozac and Zoloft) - fluoxetine is the chemical used
tricyclics (e.g anafranil) - these block serotonin and noradrenaline
anti anxiety drugs:
GABA is known as an inhibitory neurotransmitter
It slows down, or inhibits, activity in the brain, Think of the way alcohol slows your mind down
some drugs increases GABA, making us less anxious
- benzodiazepines (BZ’s) e.g. valium, diazepam, librium
other drugs affecting GABA are used too

Question 2

what is GABA.

Answer 2

gamma-aminobutyric acid

a neurotransmitter that regulates excitement in the nervous system, thus acting as a natural form of anxiety reducer

Question 3

what is noradrenaline

Answer 3

a neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity, e.g. blood pressure or heart rate

Question 4

what is serotonin

Answer 4

a neurotransmitter implicated in many different behaviours and physiological processes, including aggression, eating behaviour, sleep and depression

Question 5

summarise the use of drug therapy (biological approach) to treating OCD

Answer 5

antidepressants increase serotonin
SSRI’s - prevent re-uptake of serotonin by pre-synaptic neurons
tricyclics - block re-uptake of noradrenaline and serotonin but have more severe side effects, so are second choice treatment
anti-anxiety drugs - BZ’s enhance GABA, a neurotransmitter that slows down the nervous system
D-cycloserine - reduces anxiety (Kushner et al)

Question 6

evaluate the biological approach to treating OCD

Answer 6

effectiveness - SSRI’s better than placebo over a short term
drug therapies are preferred - less time and effort than CBT, and may benefit from interaction with caring doctor
side effects - not so severe with SSRI’s e.g. insomnia. More severe with tricyclics e.g. hallucinations and BZ’s e.g. addiction
not a lasting cure - patients relapse when treatment stops, because of this CBT may be preferable
publication bias - more studies with positive results published which may bias doctor preferences.

Question 7

explain the worry circuit

Answer 7

the OFC sends ‘worry’ signals to the thalamus
these are normally suppressed by the caudate nucleus but, if damaged, then the thalamus is alerted and confirms the ‘worry’ to the OFC, creating a worry circuit