What is commonly used to help a friend with anxiety, eating disorder, and depression?

Therapy and meds: You could recommend they see a therapist for psychotherapy, particularly dialectical behavioral therapy (dbt), as well as possible an antidepressant for relief of depression and anxiety. If the depression and anxiety is relieved, sometimes that can help with comorbid eating disorders, but they are notoriously difficulty to treat. A support group may also be helpful.