Screening people for studies isn’t really clinical experience - that more falls under the umbrella of being able to conduct research with clinical populations. That’s important, and does give you a leg up over someone who didn’t have experience doing research with clinical populations. By “clinical experience” I was more referring to students who do things like shadow psychiatrists or psychologists and volunteer at hospitals and mental health clinics. Some programs emphasize this more than others, so I think it depends on where you’re applying and what your goals are.