Aims: To assess the patterns of use, subjective effect profile and dependence liability of mephedrone, supported by corroborative urine toxicology.

Design: Cross-sectional structured telephone interview.

Setting: UK-based drug users associated with the dance music scene.

Participants: A total of 100 mephedrone users, recruited through their involvement with the dance music scene.

Measurements: Assessment of pattern of use, acute and after effects, DSM dependence criteria and gas chromatography-mass spectrometry urinalysis.

Findings: Mephedrone consumption results in typical stimulant-related subjective effects: euphoria, increased concentration, talkativeness, urge to move, empathy, jaw clenching, reduced appetite and insomnia. Thirty per cent of the sample potentially met criteria for DSM-IV dependence and there was evidence of a strong compulsion to use the drug (47% had used the drug for 2 or more consecutive days). Self-reported recent consumption of mephedrone was confirmed by toxicological analysis in all of the 14 participants who submitted a urine sample.

Conclusion: Mephedrone has a high abuse and health risk liability, with increased tolerance, impaired control and a compulsion to use, the predominant reported dependence symptoms.