Figure 2.

Quartiles of orexin median concentrations (pg/mL) by administration routes in opiate addicts. In total, significant differences of orexin concentrations for chasing the dragon, injection, and other routes of drug administration were found by Kruskal-Wallis test (χ ² = 10.201, P < 0.01). As a result of that, α = 0.0167 was used when tests were calculated between any two groups. ^#No significant difference in comparison with other routes of drug administration (Mann-Whitney U = 1991.500, P = 0.332). ^†Significantly different from administration route of injection (Mann-Whitney U = 5577.000, P = 0.005). ^‡Significantly different from other routes of drug administration (Mann-Whitney U = 661.000, P = 0.013).