As parents who’ve been in your shoes, we’ve learned that what’s important to look for isn’t a checklist but patterns that persist. A sign that your child’s substance use is becoming serious is when it starts affecting multiple areas of their life – grades may drop, old friendships dissolve, new and unfamiliar friends emerge, and communication breaks down. You feel like you’ve lost your child and the relationship is deteriorating. Trust that parent instinct that’s telling you something’s not right, and work on approaching your child with concerned curiosity.