He's provided nothing that indicates a psychological issue, or one that's been diagnosed in the past. Petty theft and possession of alcohol or marajuana as a juvenile ten years ago do not equate to a psychological or medical problem, and have no bearing on the medical certificate.
Whatever he's been doing to get several tickets in the last few years needs to stop; shouldn't be any tickets in the last few years, but those won't impact a medical certificate.
Regardless of whether the crime occurred before or after age 17, the information provided gives no basis for a psychological deferral or requirement for a psychological exam.