Patterns in drug use in the United Kingdom as revealed through analysis of hair in a large population sample

Abstract This paper presents an overview of the most common sectioning patterns utilised in the analysis of hair for drug use; report on the major user groups (sectors) that currently make use of hair analysis in the United Kingdom (UK); present the results for the different drug groups analysed in samples of hair samples analysed at TrichoTech between 2001 and 2005. A total of 186,084 tests on 34,626 hair samples were performed for the commonly requested drug groups. There were 145,799 enzyme-linked Immunosorbent positive screening tests (ELISA), which were subsequently confirmed by gas chromatography equipped with mass spectrometry detection (GC–MS). The two major sectors were the Medico-Legal sector (65%) and Workplace (20%). Police (Forensics), Clinical Monitoring, Schools, Research and Insurance accounted together for the remaining 15% of the samples. Combinations of several sections patterns were requested covering periods from the most recent month up to 24 months. The most common sectioning pattern was one single section measuring 3 cm, to cover the most recent 3 months (44%), which in some cases was complemented by a further 3 cm to cover together 6 months (13%). The second most common sectioning pattern was the analysis of three sections of 1 cm each to cover the most recent 3 months (28%), when a more detailed evaluation of drug use pattern was relevant. Samples collected from other areas of the body such as axilla, pubic, chest, beard and leg, constituted 6% of the samples. The analysis of monthly sections plays an important role in the evaluation and interpretation of drug use, particularly in certain Medico-Legal cases. The sectors with the highest rates of positive results were Police (Forensics) (78%), Medico-Legal (62%) and Clinical (54%). The common drugs in each group were cannabinol (27%), cocaine (25%), morphine (17%), amphetamine (13%) and diazepam (15%). The positive rate for the Workplace sector was 10%. The most common drugs detected in the Workplace samples in each group were: THC (4%), codeine (2%), cocaine (2%), MDMA (0.5%) and diazepam (0.1%). The concentration levels of drugs found in samples from the workplace were lower than in the other sectors (95% of cases). The exceptions were for dihydrocodeine and MDMA, where levels were 170 and 143% higher, respectively. However, the maximum levels detected in the Workplace samples were lower. The Medico-Legal sector is the most prevalent sector using hair analysis in the UK but the r