Do they typically drug test before prescribing ADHD medication?

A friend of mine recently talked to a GP about their adult ADHD for the first time and was referred to a psychologist for diagnosis. They now have a follow-up appointment with the GP for treatment, and want to know if they will be drug tested. They are an occasional user of cannabis and have also self-medicated with adderall (they know this is a bad idea and do not like doing it, which is why they decided to get tested themselves). The follow-up appointment is scheduled for tomorrow, but could be postponed long enough to ensure a clean system if needed. Thanks for any help!