Eating Disorders Exam 3

ventral medial hypothalamus (VMH)

• helps you know when you’re full

  • lesions (destruction) cause overeating/elevated weight

  • stimulation causes starvation

lateral hypothalamus (LH)

• helps you know when you’re hungry

  • lesions (destruction) cause starvation

  • stimulation causes overeating/elevated weight

brain activity and neurotransmitters

• within brain cells (neurons), signals are carried electronically

• between neurons, signals are transmitted by chemicals (NTs)

  • serotonin (5-HT)

  • dopamine

  • norepinephrine

serotonin/EDs

• serotonin involved i’m regulation of appetite, mood, impulse control

  • decreases food intake/weight

• serotonin hypothesis of EDs

  • AN caused by over-function of serotonin

  • BN caused by under-function of serotonin

• studies:

  • studies DON’T support serotonin hypothesis for AN

  • studies DO support serotonin hypothesis for BN

leptin

• reduces food intake

• genetic mutation makes mice unable to make leptin

  • overeat, low metabolism, weight gain, development of diabetes in adulthood (impacts of not being able to make leptin)

ghrelin

• “hunger hormone”

  • results in increased food intake

cholecystokinin (CCK)

• regulates gastric emptying and induces satiety

glucagon-like peptide 1 (GLP-1)

• stimulates insulin secretion

peptide tyrosine tyrosine (PYY)

• “satiety hormone”

twin studies

• MZ

• DZ

• results:

  • concordance (shared genes) for EDs is higher in MZ compared to DZ teens post-pubertally

    • one twin most likely to have ED offer puberty if other twin has ED

  • twins are not at increased risk for EDs

steiger et al. (2011)

• if certain alleles/genotypes are most common in ED participants than controls, then this allele/genotype may increase risk for ED

• background

  • women w/ BN more likely to report histories of sexual/physical abuse

  • women w/ BN have higher cortisol levels, suggesting HPA-axis dysfunction

  • the C-allele (compared to G allele) of the Bcl 1 gene has been linked to higher cortisol response following a stressor via its influence on glucocorticoid receptors

• hypothesis:

  • C allele of the Bcl 1 gene represents a diathesis (vulnerability) and abuse represents a stress that causes BN

  • there should be a significant interaction between history of abuse/Bcl 1 gene in predicting presence vs. absence of BN

• IVs

  • either no history or only history

  • genotype (CC, GC, or GG)

    • GG

    • C allele carrier (CC or CG/GC)

• DVs

  • presence vs. absence of BN

    • 129 female patients w/ BN

    • 98 “normal-eating” women

• results

  • C allele

    • women w/ BN more likely to carry allele of Bcl 1 gene

  • abuse

    • women w/ BN report greater history of abuse compared to controls

  • odds ratio

    • individual affects of either a allele or abuse are eliminated in their interaction together

      • interaction between them is significant → they influence each other

• conclusions

  • women w/ BN report greater history of abuse compared to normal eaters

  • women w/ BN more likely to carry C allele of Bcl 1 gene

  • both effects eliminated when evaluating interaction

  • combination of diathesis (c allele)/stress (abuse) that particularly predicts risk for BN

    • having both together increases risk for BN, not them individually

consequences of starvation

• dry, brittle hair, skin, nails

• fine hairs grow on body → lanugo; tries to keep you warm due to the lack of fat on the body

• constipation

• amenorrhea

• osteoporosis/bone fractures

• impaired immune system

• muscle loss

• major organ failures

  • cardiovascular complications

    • arrhythmia, heart failure

purging complications

• electrolyte imbalance due to self-induced vomiting/diuretic/laxative mouse (can lead to heart failure)

  • electrolyte imbalance is the effect of multiple purging methods

• erosion of dental enamel

• hypersensitive gag reflex

• ruptured esophagus/stomach

consequences of binge eating

• elevated weight

  • correlated cardiovascular, metabolic consequences

• compromised gastrointestinal function

  • enlarged gastric capacity

  • delayed gastric emptying

  • gastric emptying (rare but deadly)

inpatient treatment

• this is when the patient is admitted to the hospital

  • reserved for the medically severe cases/those at-risk of suicide

• most expensive

  • average cost of one month of this treatment → $30k

residential treatment

• full-time treatment → go to a center where everyone’s getting treatment

• resource intensive

  • average duration is about 83 days → average cost is $956/day, $79,348 (2006)

• this is mostly limited to individuals w/ resources to cover the costs

  • insurance and disposable

outpatient treatment

• this is when the patient sees a therapist/professional

• costs substantially less compared to the other methods

  • $4k for a full course of CBT; $200/hr.

  • about $1,689 for full-course CBT w/ Medicare/Medicaid reimbursement level

• have to consider the safety/health, efficacy

  • if someone’s at risk of death, this may not be the right treatment method for them

within-subjects designs

• participant serves as their own control → changes in the same person over time

  • assess the baseline symptom level

  • begin treatment → reassess symptom level

  • discontinue after effective component of treatment → reassess symptom level

• if the treatment is impacting the symptoms, then changes in the symptoms should be observed w/ changing presence and absence of the active treatment

• limits:

  • limited generalizability → what works for one may not work for others

  • once patient is recovered, they never have the opportunity to test whether a different treatment would have been better/worse

  • not ethical to withhold treatment that you know works

between-subjects designs

• comparing the outcomes between two groups → those who receive intervention vs. those that don’t receive intervention (or receive another one)

  • different people are the controls

  • IV → treatment condition or the group to which the patients belonged

  • DV → recovery, symptom reduction, something along those lines

randomized controlled trials (rct)

• type of between-subjects design

  • active treatment group or control group (random assignment)

    • observes outcomes after treatment → did the number of people who recovered differ between the groups?

random assignment

• increases the representativeness of those in a condition to the population that’s seeking treatment

• reduces the likelihood that differences before the treatment (ex: differences in symptom severity) influence comparison of outcomes between the conditions

empirically supported interventions

• evidence suggests that this is a good treatment

• produce superior outcomes compared to control conditions

  • no treatment/waitlist or placebo or alternative treatment

• also called evidence-based treatments

waitlist control

• between-subjects design (w/ treatment group)

  • compare people who receive the intervention to the people placed on a waiting list for the treatment

    • whether the treatment is better than doing nothing

placebo control

• between-subjects design (w/ treatment group)

  • compare people who receive intervention to people who receive fake treatment

    • mimics treatment pills (thinking you’re getting the treatment may actually help even if you’re not actually getting it)

alternative treatment control

• between-subjects design (w/ treatment group_

  • compare people who receive the treatment to people given a different kind of intervention

    • two treatments studied compared to just one

comparing treatment modes

• three types:

  • specialized inpatient treatment

  • specialized outpatient treatment

  • general (routine) treatment through a service in England

• acceptance/satisfaction

  • acceptance of randomization (treatment) greater for the outpatient care

  • both specialist treatments preferred over general outpatient treatment

• outcome

  • no differences in outcome across treatment modalities

    • didn’t matter what you received in terms of the final improvements

  • improvement observed over time (good, but slow)

• cost effectiveness

  • to achieve the same outcomes from cheapest to most expensive

    • specialist outpatient → general outpatient → inpatient

• conclusions

  • specialist outpatient treatment determined to be the superior treatment modality

    • it’s acceptable to patients and results in higher satisfaction

    • produces outcomes that are just as good as the other options

    • costs the least amount of money

CBT for BN

• Fairburn’s three stages

  • CBT Stage 1

  • CBT Stage 2

  • CBT Stage 3

Fairburn’s stage 1

• identify the triggers and tackle them

  • establish control over eating w/ behavioral techniques

    • self-monitoring of food intake/symptoms w/ diary

    • prescription of a regular pattern of eating

      • ex: every 2/3 hours → 3 meals + 2/3 snacks

    • stimulus control (identify triggers to binge eating + avoid/employ incompatible behaviors)

    • psychoeducation on weight regulation, dieting, risks of purging

fairburn’s stage 2

• explore the distorted thoughts and poke holes in them

• reduce dieting/body image disturbance though a combination of behavioral/cognitive techniques, engaging in problem solving

Fairburn’s stage 3

• maintenance of progress/reduction of risk for future relapse

  • ex: recognize and challenge dichotomous thinking to prevent lapses from becoming relapses

• frequency of sessions transitions from initially being twice/week, once/week to twice/month, once/month, ending