Disparity between claimant's symptoms and medication prescribed did not compel conclusion that doctor was inaccurate in describing severity of claimant's mental impairments, even though that inference could be drawn. Doctor was a general practitioner, not a psychiatrist. Court comments that ALJ's conclusion about schizophrenic claimant's mental RFC is incredible and that the evidence was not weighed in and sifted in a balanced and even-handed manner. ALJ had already heard case initially and on remand from district court. Testimony of a non-examining medical advisor--to be distinguished from the non-testimonial written reports in the instant case--can alone constitute substantial evidence, depending on the circumstances.