Many posters on this forum have addicted loved ones with additional psych disorders who are on meds for their problems. Overuse/misuse of prescribed meds can cause serious problems. However, it is a personal and complicated issue. Your sister may feel her social anxiety is adequately managed through medication and may not want to pursue other ways to address her problem. If your sister's meds are legally prescribed and she takes them as prescribed, then it is a matter between her and her doctor. If you have expressed your concerns to her, then you have done what you can. You could try speaking to her doctor but he/she is under no obligation to address your concerns. I doubt you'd get far in reporting the doctor unless you have strong evidence that he/she is doing something illegal.