Anorexia Nervosa
Conditions
Keywords
Theta Burst Stimulation, Neuromodulation, Psychiatric Disorders, Transcranial Magnetic Stimulation, Anorexia Nervosa, Eating Disorders
Brief summary
Anorexia Nervosa (AN) is a life-threatening eating disorder characterised by an intense fear of weight gain and disturbed body image, which motivates severe dietary restriction or other weight loss behaviours (e.g. purging). Treatment efficacy in adults with AN remains low: only a small percentage of individuals fully recover, and dropout rates are high. For adolescents with a relatively short term illness duration (under 3 years), family-based therapy has been associated with more favourable outcomes. However, for those adolescents with a longer illness duration (over 3 years), there are no specific treatments associated with positive long-term outcomes and these individuals are at risk of developing a severe and enduring form of the illness (SE-AN). In part, treatment can be problematic due to ambivalence, which is reflected in poor take-up of certain treatments (e.g. pharmacological treatments that lead to weight gain) and high drop-out rates. Repetitive transcranial magnetic stimulation (rTMS) has demonstrated efficacy for treatment of AN in adults and improving treatment adherence. However, this has yet to be investigated in adolescents with AN. This study will use a novel type of rTMS, theta burst stimulation (TBS), including intermittent TBS (iTBS) and continuous TBS (cTBS). TBS takes as little as a few minutes duration compared to the classical rTMS protocol which takes approximately 37.5 minutes. In addition, TBS has been found to produce longer after-effects of the induced plastic changes and has a lower stimulation intensity, which may therefore be more practical and potentially safer to administer in people with AN. Thus, the aim of this proof-of-concept trial is to obtain preliminary data on the safety and short-term (i.e. up to 24 hours) effects of a single session of iTBS and cTBS, compared to sham TBS, on reducing core symptoms of AN.
Interventions
DEVICEIntermittent Theta Burst Stimulation
The Magstim Rapid2 Magnetic Stimulator (Magstim ®, UK) will be used to administer active TBS.
The Magstim Rapid2 Magnetic Stimulator (Magstim ®, UK) will be used to administer active TBS.
The Magstim Rapid2 Magnetic Stimulator (Magstim ®, UK) will be used to administer TBS using a sham Magstim coil.
Sponsors
South London and Maudsley NHS Foundation Trust
King's College London
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Researcher unable to be blinded as stimulation site is dependent on the participants allocation to intermittent or continuous TBS.
Intervention model description
Participants will be randomly allocated to one of three treatment arms: continuous TBS or intermittent TBS or sham TBS.
Eligibility
Sex/Gender
ALL
Age
13 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Male and female participants over the age of 13 * BMI over 14 (for participants over the age of 18) or over 66% of the median BMI for age and gender (for participants under the age of 18) * Right-handed * Current Diagnostic and Statistical Manual-5 (DSM-5) diagnosis of AN-restricting type (AN-R) or AN-binge/purge type (AN-BP) and an illness duration of 3 years or more * Must have completed at least one adequate previous course of eating disorder treatment (e.g. one 6-month course of specialist outpatient therapy, specialist day-care or in-patient treatment for re-feeding) * Participants under the age of 18 must have informed consent from parent(s)/carer(s) * Must have approval from treating eating disorders clinician or general practitioner (GP) to participate
Exclusion criteria
* Having a history of head or eye injury * Having a history of a neurological disease including previous seizures of any kind * Having metallic implants anywhere in the head or body * Being on a dose of any psychotropic medication that has not been stable for at least 14 days prior to participation in the study * Taking antipsychotic medication * Taking anti-convulsive medication * Pregnancy or suspected pregnancy in female participants * Having a current other major psychiatric disorder (e.g. major depressive disorder, substance dependence, schizophrenia or bipolar) needing treatment in its own right * Excessive alcohol (\>3 units per day, 5 days of the week) and/or cigarette consumption (\>15 cigarettes per day) * Severe abnormalities in the screening clinical blood sample * An rTMS safety questionnaire and an MRI safety questionnaire will also be administered and if deemed not safe to deliver rTMS or undergo MRI scanning, people will be excluded on this basis.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes and differences between the 3 groups in core symptoms of AN from baseline to post-TBS | Baseline, within 1 hour after receiving [intermittent/continuous/sham] TBS, 24-hour follow-up | Core symptoms of AN are computed by summing scores on three 10cm visual analogue scales (maximum score of 30) that assess levels of urge to restrict, feeling full, and feeling fat. Participants are requested to indicate on this line a degree or level of experiencing the specific emotion or behavioural urge from not at all to severe |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes and differences between the 3 groups in heart rate from baseline to post-TBS | Baseline and within 1 hour after receiving [intermittent/continuous/sham] TBS | Measures of heart rate (beats per minute) will be taken to assess cardiac safety of TBS in patients with AN |
| Changes and differences between the 3 groups in blood pressure from baseline to post-TBS | Baseline and within 1 hour after receiving [intermittent/continuous/sham] TBS | Measures of blood pressure (millimetres of mercury; mmHg) will be taken to assess cardiac safety of TBS in patients with AN |
| Differences between the 3 groups in self-reported ratings of discomfort experienced during TBS | Within 1 hour of receiving [intermittent/continuous/sham] TBS | Discomfort experienced during TBS will be measured using a 10cm visual analogue scales (maximum score of 10). Participants will be requested to indicate on this line a degree or level of discomfort experienced during TBS from none to extreme discomfort |
| Changes in performance on the Two-Step Sequential Learning Task from baseline to post-TBS | Baseline and within 1 hour of receiving [intermittent/continuous/sham] TBS | Neuropsychological task measuring model-based and model-free reinforcement learning |
Countries
United Kingdom
Contacts
Primary ContactLucy J Gallop
Outcome results
None listed