Treatments for AN - Drug Therapy Flashcards
How are drug treatments effective
Biochemical mechanisms (dopamine and serotonin) should be able to alter neurotransmitter activity may benefit AN symptoms.
Two types of drug treatments
Antidepressants
Antipsychotics
What do antidepressants do
Increase serotonin/ serotonin and noradrenaline in synapse
What do antipsychotics do
Dopamine abnormally high in AN. Block postsynaptic receptors so dopamine cant bind, reducing signals.
Two type of antidepressant drugs
SSRIs (selective serotonin reuptake inhibitors)
SNRIs (serotonin-noradrenaline reuptake inhibitors)
Why does low serotonin cause AN
may be direct cause of AN or be because AN is co-morbid with depression
What does serotonin do normally
remaining in synapse are normally removed by process of reuptake
Taken back into presynaptic neuron through serotonin transporter
What happens to serotonin when drug is taken
block serotonin reuptake in presynaptic so excess serotonin is not recycled, instead stays in synapse and repeatedly binds with postsynaptic receptors
How do SSRIs and SNRIs help people with AN
Extends the appetite-enhancing effects of serotonin
How do SNRIs work
-Work in similar way to SSRIs but target noradrenaline as well as serotonin (inhibiting reuptake of both serotonin and adrenaline)
What do SNRIs suggest
low serotonin is not only neurotransmitter dysfunction that afffects AN
What happens do SGAs do to neurotransmitters
Dopamine antagonists = blocks postsynaptic dopamine receptors without activating them, reducing dopamine activity
Block D2/D3 and serotonin 5HT2A receptors
Increase grehlin
How do SGAs help with anorexia
Olanzopine = decrease obsessive thoughts (anorexic ruminations)
Ghrelin = decrease fullness and encourage food intake -> Van der Zwaal 2012
Atypical second-generation antipsychotics
SGAs - Olanzopine
Why is it a weakness to just treat AN with SGAs or SSRIs/SNRIs
-Weight gain = dealing with symptoms but not underlying causes. Make them mentally worse because people with AN are scared to gain weight.
Strength of SGAs
-Boachie et al (2003)
- Olanzapine to treat 4 children with AN
-Gained weight (under 1kg a week)
-Experienced less anxiety at mealtimes, with few side effects
Counter argument to SGAs
Kafantaris et al (2011) = 15 adolescents given olanzapine
-gained weight and improved eating attitudes BUT at same rate as control group
-Case studies limited (have no control group)
-Used randomised control trial
-Findings from RCTs have been mixed
Weakness study
Lebow et al (2013): SGAs
-increase BMI & body satisfaction BUT greater anxiety and worse overall symptoms
-No sig dif from placebo
Another weakness of drugs effectiveness - look at only symptoms
-Drugs look at symptoms of AN not causes
Drugs reduce symptoms of AN by stabilising dysfunctional neurotransmitter systems in the brain
Temporary and reversible reduction in symptoms is not the same as treating the cause (ultimately genetic or psychological)
Psychological therapy such as CBT might be preferable (with few side effects)
National Institute for Health and Care Excellence (NICE) – states that drugs should not be used as a primary or only treatment for patients with anorexia nervosa, and there is very little evidence that states that drugs are a useful treatment for anorexia.
Application
Most side effects are mild to moderate some are serious but rare. Side effects can be controlled and reduced through monitoring, adjustment of dose and in some cases additional medication.
Knowledge of side effects increases acceptability for people with AN = more likely to continue treatment
