not all PhD programs necessarily conduct background checks on their applicants. The decision to conduct background checks can depend on a variety of factors, including the specific field of study, the policies of the individual institution, and any relevant laws or regulations.
In fields like clinical psychology, where students might interact with vulnerable populations (such as in practicum or internship experiences), it is possible that a background check could be required. This is because the safety of clients/patients is a priority and practitioners need to demonstrate they can handle the responsibility of working with people in a therapeutic context.
However, this isn't universally the case, and the specifics can vary widely. For example, some programs may conduct background checks only on students who are accepted into the program, while others might conduct checks during the application process. The specifics of what a background check would entail (e.g., criminal history, educational background) can also vary.
As always, if you are considering applying to a particular program and are concerned about this issue, I would recommend reaching out directly to the program's admissions office. They can give you the most accurate information about their specific policies and procedures.