725 ILCS 5/115-7.2

In a prosecution for an illegal sexual act perpetrated upon a victim, including but not limited to prosecutions for violations of Sections 11-1.20 through 11-1.60 or 12-13 through 12-16 of the Criminal Code of 1961 or the Criminal Code of 2012, or ritualized abuse of a child under Section 12-33 of the Criminal Code of 1961 or the Criminal Code of 2012, testimony by an expert, qualified by the court relating to any recognized and accepted form of post-traumatic stress syndrome shall be admissible as evidence.