Hypothesis: Will the use of tDCS brain modulation in the cerebellum assist in restricted behaviors, social cognition and cognitive flexibility in women with anorexia nervosa in addition to other therapies?

Primary Outcomes:

1. To observe the impacts and outcomes of cerebellar transcranial direct current stimulation (tDCS) on social behaviors measured by Cyberball and Trust Game.
2. To observe the neuropsychological impacts of cerebellar tDCS through fMRI imaging as well as looking at the Region of Interest (ROI) of changes in the Default Mode Network and Cerebellum circuits and their activation levels in those networks.

Secondary Outcomes:

1.To observe the impacts and outcome of cerebellar transcranial direct current stimulation (tDCS) measuring the differences between anodal and cathodal stimulation. To observe potential increases in responses to social stimuli, decreases in eating disorder/depressive symptomology via cathodal stimulation. To also observe potential little to no changes in social stimuli and eating disorder/depressive symptomology via anodal stimulation.

The study will be randomized, single blind design. It will involve a group of 15 female participants ranging in the ages of 15-30 years old diagnosed with Anorexia Nervosa. Diagnosis will be confirmed by recruitment methods of in-clinic referrals. Each participant will undergo the two different electrode stimulations of the tDCS. Each participant will get anodal and cathodal stimulation. The participants will be unaware of which one they are getting during stimulation, but the researcher will be informed of which stimulation is occurring. The participant will receive 1mA stimulation of the tDCS for 20 minutes in the MRI scanner. After the stimulation is complete in the scanner, the participant will be asked to complete tasks in the scanner as well. The study involves initial screening to determine eligibility to participate. Once eligibility criteria is met, the participant will sign consent via DocUSign. After this virtual visit is complete, the participant will be asked to come in for intake visit. At the intake, the participant will undergo a series of questionnaires and tasks to complete as part of pre-scanning. The next session will be stimulation and MRI imaging. Participant will undergo resting state and a structural scan. After the scans are complete, the participant will receive 20 minutes of tDCS stimulation. After the simulation is complete the participant will be asked to engage in tasks in the scanner. Finally, after the scanning session, the participant will come back for a post session that is the same as the intake and undergo questionnaires and tasks to complete. After the post session, researchers will reach out to participants one week and one month after MRI imaging to go over safety questionnaire of the tDCS. The participant will have a total of 5 sessions which may include both in-person and/or virtual visits with screening session, first session, second session, one week follow-up session, and one-month follow-up session.

Inclusion Criteria:

• Diagnosis of Anorexia Nervosa (AN)
• Female participants
• Age 15-30 years old inclusive at time of enrollment
• Ability of parent or legal guardian to provide informed consent if participant is under 18 years old.
• Ability of patients ages 15-17 to give assent to the study.
• Completion of the signed HIPAA authorization form by a parent or legal guardian or by participants (18 years of age).

Exclusion Criteria:

• Pregnancy
• Known history of traumatic brain injury that required medical care
• Non-English speaking (based on standardized neuropsychological testing and questionnaires)
• Claustrophobic
• Brain Implants
• Pacemakers
• Hearing or visual impairment
• Any biomedical or metal implants in any part of the body (excluding orthopedic implants)

Must be female/ biologically female