Drug testing, when carefully collected and thoughtfully interpreted, offers a critical adjunct to clinical care and substance use treatment. However, because test results can be misleading if not interpreted in the correct clinical context, clinicians should always conduct a careful interview with adolescent patients to understand what testing is likely to show and then use testing to validate or refute their expectations. Because of the ease with which samples can be tampered, providers should also carefully reflect on their own collection protocols and sample validation procedures to ensure optimal accuracy.”