Table 5.

Correlation analysis of candidate gene methylation levels with methamphetamine abuse characteristics in three groups (r).

	HMAQ group (n = 168)			LMAQ group (n = 39)			Health control (n = 105)
	Age	Age of first drug abuse	Total drug abuse time (months)	Age	Age of first drug abuse	Total drug abuse time (months)	Age
CAV2	−0.101	0.105	−0.069	0.351*	0.308	0.405*	0.078
BHLHB9	0.103	0.129	0.145	0.288	0.368*	0.312*	−0.132
PCSK9	−0.014	0.004	0.156	−0.235	−0.191	0.134	0.046
SLC1A6	0.146	−0.098	0.009	0.117	0.129	−0.059	0.017
LYNX1	0.023	−0.044	0.104	−0.149	−0.057	−0.203	−0.129

Methylation copies of the CAV2 gene were significantly associated with age and total duration of drug abuse in the LMAQ group. The methylated copies of the BHLHB9 gene were significantly correlated with the age of first drug abuse and the total duration of drug abuse in the LMAQ group.

^*p < 0.05.