Why do I feel so cognitively dumb even though I am on medicine?

17M. I have been medicated for about a month now, but now I feel really dumb still and its really hard for me to think straight, and I was under the impression that the medicine(Risperadone) would help, but so far i still feel very dumb. Can anyone who has experienced Schizophrenia for longer let me know if this is normal, and I just haven't been medicated long enough or if I should ask to switch medicines because this is very frustrating for me. Thanks!