730 ILCS 5/5-2-5

In any issue of determination of fitness of a defendant to plead, to stand trial, to be sentenced or to be executed, or in any issue related to insanity or to mental illness, a clinical psychologist as defined in paragraph (a) of Section 102-21 of the Code of Criminal Procedure of 1963 shall be deemed qualified to testify as an expert witness in the form of his opinion about the issue of fitness or insanity or mental illness and shall not be restricted to testifying with regard to test results only.