Pot use is difficult to detect. But since virtually all poly-drug use (the use of several drugs at the same time) starts with chronic pot use, parents should be aware of the following signs of the marijuana-using youngster. However, experts point out kids may have only some symptoms, and some pot-using kids have none.

1. The most obvious sign is finding a pot pipe, marijuana rolling papers, a cellophane "baggie" of marijuana 'and/or drug paraphernalia (bongs" etc.) for using or hiding pot. Don't be reassured by your kid's insistence that "Johnny must have left it here." (Unfortunately, a classic symptom of the drug-abusing youngster is lying.)

2. Red eyes. Many youngsters take care of this with eye drops - which, in themselves, are a suspicious sign.

3. A distorted time sense. If you suspect your child is stoned, ask him to click his fingers when a minute is up. They're likely to do this after 10 or 20 seconds. (Stoned drivers often think they're driving slowly, carefully, when they may be speeding.)

4. A drop in school performance. Not necessarily from A's to D'S, but from A's and B's to C's, for example.

5. Caring less about everything; school, sports, other extracurricular activities, and hobbies the children use to enjoy.

6. A change from active, normally competitive interests to passivity and withdrawal.

7. General loss of appetite, yet craving for sweets ("the munchies").

8. Estrangement from the family; inexplicable mood changes, irritability, hostility. Strongly inappropriate overeaction to mild criticism.

9. Impairment of short-term memory, judgment, capacity to reason and to think clearly.

10. A chronic cough, chest pains, depression, feelings of loneliness.

11. Feelings of paranoia. Fatigue and loss of vitality. "Flattened" speech and expression. Sleep disturbances. Menstrual irregularities.

12. Strange phone calls, secretiveness, vagueness about social activities. Friends who refuse to identify themselves or hang up when you answer the phone.

13. Less attention paid to deadliness' of body, hair, and clothes.

14. Disappearance of money or items of value from the home.

15. Impaired ability to fight off common Infections.