Top three most harmful drugs to users:
- heroin
- crack
- crystal meth
Top three most harmful drugs to others:
- alcohol
- heroin
- crack
Most harmful overall, based on nine categories of harm including physical harm, mental harm, and damage to relationships (scores out of a possible 100):
- alcohol (72)
- heroin (55)
- crack (54)
- crystal meth (33)
- cocaine (27)
- tobacco (26)
- amphetamine/speed (23)
- cannabis (20)
- GHB (18)
- benzodiazepines (15)
- ketamine (15)
- methadone (13)
- butane (10)
- qat (9)
- ecstasy (9)
- anabolic steroids (9)
- LSD (7)
- buprenorphine (6)
- magic mushrooms (5)