Table 6 Multiple linear regression analysis of the predicting variables of psychosocial problems (β standardized regression coefficients and p value at <0.05)

Sex (Reference-female)

-0.220 (0.001)

Education

-0.260 (<0.001)

Age of initiation of substance use

-0.177 (0.010)

-0.181 (0.011)

-0.168 (0.001)

-0.171 (0.011)

Licit substance user (Reference- both licit and illicit substance user)

-0.142 (0.42)

-0.343 (<0.001)

-0.204 (0.007)

-0.214 (0.004)

-0.260 (<0.001)

-0.344 (<0.001)

-0.364 (<0.001)

-0.324 (<0.001)

Frequency of substance use

0.242 (<0.001)

Mode of substance use (Reference-non injecting substance user)

0.241 (0.001)

0.160 (0.015)

0.227 (0.001)

0.146 (0.048)

0.251 (0.025)

0.261 (<0.001)

0.225 (<0.001)

R ² = 0.21

R ² = 0.28

R ² = 0.23

R ² = 0.09

R ² = 0.17

R ² = 0.35

R ² = 0.42

R ² = 0.31