what is the most commonly use biological therapy?
drug therapy
what does drug therapy assume?
chemical imbalance in the brain
what do drugs do?
increase/decrease levels of neurotransmitters
what does SSRI stand for?
selective serotonin reuptake inhibitors
what do SSRIs do?
increase certain transmitters in the brain by preventing the reabsorption of serotonin
what do SSRIs allow?
the effective increase of serotonin the synapse that can stimulate the postsynaptic neuron
what is often used alongside drugs?
CBT
why are CBT & drugs combined?
drugs reduce emotional symptoms so patient can engage more effectively with the therapy
what are the alternatives to SSRIs?
tricyclics
benzoiazepines
why are alternatives to SSRIs used?
when SSRIs are not effective after 3-4 months
what is a tricyclic?
the first antidepressant for OCD
what does a tricyclic do?
blocks the transporter mechanism that reabsorbs both serotonin & noradrenaline into the presynaptic neuron after it has been fired which prolongs the activity as they are left in the synapse
what is the advantage of using tricyclics?
they target more than one neutransmitter
what is the drawback of tricyclics?
greater side effects than SSRIs
what are benzodiazepines?
anti-anxiety drugs
how do BZs work?
slow down the activity of the CNS by enhancing the activity of GABA
what does GABA stand for?
gamma-aminobutyric acid
what is GABA?
a neurotransmitter that when released has a quieting effect on many of the neurons in the brain by reacting with GABA receptors on the outside of the receiving neurons
what does a GABA do?
locks into the GABA receptors, opening a channel that increases the flow of chloride ions into the neuron
why should the flow of chloride ions into the neuron be increased?
they make it harder for the neuron to be stimulated by other neurotransmitters, slowing down activity & making them more relaxed
what are the strengths of the biological treatment of OCD?
evidence - effectiveness tested in studies - compared to placebo - Soomro et al - 17 studies reviewed - SSRIs more effective than placebo - up to 3 months after treatment - only looks at short term
cost-effective - non-disruptive - little monitoring - unlike psychotherapy, no effort/time - favourable - economic
what are the weaknesses of the biological treatment of OCD?
side effects - significant minority - weight gain - nausea - headaches - tricyclics have more - withdrawal - relapse
unreliable evidence - drug companies sponsorship - publication bias - Turner - 31% of studies for antidepressants registered & reported to FDA were never published - inappropriate treatment decisions