Functional Magnetic Resonance Imaging (fMRI) Investigation Into Compulsivity in Anorexia

The investigators will perform four different MRI (Magnetic Resonance Imaging) scans during one scanning session on those who have recovered from anorexia nervosa (AN) and healthy controls.

Participants will come to the Warneford hospital for a 2.5 hour screening visit, which will consist of questionnaires and interviews to determine their medical and psychiatric history and current mood, along with a practice of the task they'll do in the scanner. Participants will also complete two tasks which measure compulsivity and can be correlated with their brain activity in the scans. The investigators will also go through a scanning safety form with participants at this time.

Participants will also attend a scanning visit, which will last 1.5 hours. One of the scans will look at how the brain responds to a particular task. This task will examine aspects of compulsivity (which is rigidly repeating actions that aren't rewarding) by using face and house stimuli (see reference 1).

The investigators will also perform a scan when participants are at rest, in order to see if there are differences in the way areas of the brain connect to each other who used to have AN. The scientific literature indicates that there may be differences in the some key brain networks, including one which is thought to be involved in reflection and the self (the default mode network), which might also be linked to compulsivity (see reference 2).

This study will also further investigate some initial pilot findings using Magnetic Resonance Spectroscopy, which allows researchers to examine the levels of different neurochemicals in the brain. It has been found that those with a current diagnosis of AN have lower levels of glutamate (a key brain chemical) compared to healthy controls, which is a finding we seek to extend in those who have recovered from AN (see reference 3).

Aims: The investigators aim to see whether there are differences in the brains of those who have recovered from anorexia compared to those who have never had an anorexia diagnosis. This will be both at rest, and whilst participants are doing a task which measures compulsivity, as compulsivity is thought to be a particular risk factor for eating disorders.

Value: If the investigators are able to identify differences, these might reflect underlying risk factors for eating disorders, which could lead to potential future treatments or prevention schemes.

Inclusion criteria

• Able and willing to give informed consent
• BMI over 18.5 and has remained so for the last year
• Score lower than mean+1 standard deviation of global mean scores for young women on the EDE
• Fluent English speaker
• Former diagnosis of anorexia nervosa in relevant group

Exclusion criteria

• Any current diagnosis of a psychiatric disorder which in the investigator's opinion could impact study results (e.g. significant depression, anxiety or OCD).
• Any current psychotropic medications.
• Eyesight problems that would prohibit participating in a task-fMRI study.
• Current regular cigarette smoking of over 5 cigarettes per day.
• Recent use of illicit drugs.
• Alcohol intake which indicates an element of alcohol abuse; or unwillingness to refrain from drinking the night before the study visit.
• Any contraindications to MRI scanning (including claustrophobia).
• Participant is pregnant or breast-feeding.