Stress and Neurofeedback in Anorexia Nervosa

Inclusion Criteria: Healthy Controls (HC) * Individuals aged 18-45 years * Healthy body weight between 90 and 110 % average body weight since puberty. * Regular monthly menstrual cycle (if applicable) * Edinburgh Handedness Inventory Revised (EHI-R) LQ\* score \> +200 * All ethnic backgrounds * English is primary language spoken Anorexia Nervosa (AN) * Age 18-45 years old * Edinburgh Handedness Inventory Revised (EHI-R) LQ\* score \> +200 * All ethnic backgrounds * Current diagnosis of anorexia nervosa, including being underweight, will have a severe fear of weight gain, body image distortion and absence of the menstrual cycle over three consecutive months. * English is primary language spoken Atypical Anorexia Nervosa (AAN) * Age 18-45 years old * Edinburgh Handedness Inventory Revised (EHI-R) LQ\* score \> +200 * All ethnic backgrounds * Meets the criteria for anorexia nervosa except despite significant weight loss, the individual's weight is within or above the normal range * English is primary language spoken Exclusion Criteria: Healthy Controls (HC) * Current pregnancy or breast feeding within last 3 months * First degree relative with current or past eating disorder * Psychiatric Medication use such as selective serotonin reuptake inhibitors (SSRIs), atypical antipsychotics, etc. * Past or present Axis I psychiatric disorder including substance or alcohol use disorder as determined through structured clinical interview * History of significant head trauma * Indication of intellectual disability or autism spectrum disorder * Major Medical illness that requires medication or have significant impact on subject's life such as: diabetes, Alzheimer's disease or dementia, stroke, learning disability, mobility disorders, cancer, high blood pressure, etc. (to be determined through biological screening form and interview with principal investigator (PI) * Recent history of suspected substance abuse or a lifetime history of psychostimulant abuse and/or dependence * Contraindications to magnetic resonance imaging (MRI) including metal implants or braces (as determined through fMRI screening form) Anorexia Nervosa (AN) * Pregnancy or breast feeding within last 3 months * Lifetime history of bipolar I disorder or psychosis * Current substance abuse or dependence in the past 3 months * Psychotic illness/other organic brain syndromes, dementia, somatization disorders or conversion disorders * Physical conditions (e.g., diabetes mellitus, pregnancy) known to influence eating or weight * History of significant head trauma * Indication of intellectual disability or autism spectrum disorder * Electrolyte, blood count or kidney or liver function abnormalities * Contraindications to MRI including metal implants or braces (as determined through fMRI screening form) Atypical Anorexia Nervosa (AAN) * Pregnancy or breast feeding within last 3 months * Lifetime history of bipolar disorder or psychosis * Current substance abuse or dependence in the past 3 months * Psychotic illness/other organic brain syndromes, dementia, somatization disorders or conversion disorders * Physical conditions (e.g., diabetes mellitus, pregnancy) known to influence eating or weight * History of significant head trauma * Indication of intellectual disability or autism spectrum disorder * Electrolyte, blood count or kidney or liver function abnormalities * Contraindications to MRI including metal implants or braces (as determined through fMRI screening form)