This Polish study surveyed nearly 2,500 recreational drug users about their substance use patterns and mental health. The survey found that marijuana is the most commonly used illicit drug, but worryingly, most users don’t test what they’re taking or measure doses carefully. The study also revealed increasing use of mephedrone and other stimulants that are sending more people to hospitals, while interest in psychedelics is declining. Importantly, more people are now seeing psychiatrists and being honest about their drug use.