- Obsessive behaviors. Staying up all night to do iron or repeating the same task or phrase over and over in a compulsive manner can be a sign of certain drugs like meth.
- Missing for long periods of time and establishing new routines with new friends are common behavioral signs.
- Secretiveness. A shift in communication style to be more guarded can mean the person is trying to hide substance use.
- Drastic change in beliefs. If someone was previously very religious and focused on their family but now has time for neither, drug abuse might be a factor. Or, someone who was previously not very religious may develop preoccupations with religious content (e.g., quoting or reading the bible persistently).
- Using measures to conceal. Abusers may try to hide signs of abuse, for example by wearing sunglass inside or long-sleeves in the summer.
- Paraphernalia. Finding pill bottles, large amounts of money, empty alcohol containers, needles, scales, and other paraphilia hidden around the house are all warning signs.
- Random injuries and illness. While intoxicated, people are more likely to become injured. If someone is having more "accidents," drugs could be the culprit.