Self-reported impulsivity, but not behavioral choice or response impulsivity, partially mediates the effect of stress on drinking behavior

Figures & data

Figure 1.  Mediation model of stress, impulsivity, and drinking behavior.

Table I.  Demographics of sample.

Subject variable	N = 192
Age in years^*	30.42(9.3)
Years of education^*	14.90 (2.2)
Gender (% male)	90 (46.9%)
Race
African American (N% AA)	47 (24.5%)
Caucasian (N% Caucasian)	122 (63.5%)
Hispanic (N% Hispanic)	10 (5.2%)
Asian (N% Asian)	4 (2.1%)
Other (N% other)	9 (4.7%)
Marital status
Never married (%)	131 (68.2%)
Married (%)	37 (19.3%)
Separated (%)	0 (0%)
Divorced (%)	22 (11.5%)
Cohabiting (%)	2 (1.0%)
Widowed (%)	0 (0%)
IQ (Shipley)^*	112.8 (8.57)
Total self-reported impulsiveness (BIS-11)^*	61.7 (12.1)
Non-planning impulsiveness	23.1 (5.0)
Attentional impulsiveness	16.9 (4.7)
Motor impulsiveness	21.8 (4.6)
Total choice impulsiveness (EDT)^*	0.62 (0.2)
Total response impulsiveness (GNG)^*	23.4 (11.1)
Total CAI^*	12.4 (7.4)
Major life events^*	2.2 (1.7)
Life traumas^*	6.9 (4.7)
Recent life events^*	3.3 (2.9)
Chronic stressors^*	11.1 (6.6)
Alcohol dependent (%)	18 (9.4%)

^* Denotes mean values (standard deviations); all other measures reported in frequency (percents). CAI total = standardized major life events+standardized life traumas+standardized recent life events.

Table II.  Mediation of association of stress with drinking behavior by self-reported, choice, and response impulsivity, with gender and IQ as covariates.

	Effect of IV on M (a)	Effect of M on DV (b)	Total effect (c)	Direct effect (c′)	Indirect effect (a × b) (95% CI)	Gender on DV	IQ on DV
Self-reported impulsivity—BIS-11
IV
CAI total	0.62 *	0.16*	0.29*	0.19*	0.10* (0.06–0.17)	3.80*	− 0.13*
Trauma	0.86*	0.16*	0.47*	0.33*	0.14* (0.08–0.24)	3.58*	− 0.12*
Major life events	1.76*	0.20*	0.29	− 0.07	0.36* (0.16–0.70)	3.67*	− 0.18*
Recent life events	1.13*	0.18*	0.55*	0.35*	0.20* (0.09–0.42)	3.90*	− 0.16*
Chronic stressors	0.52*	0.19*	0.18*	0.08	0.10* (0.05–0.18)	3.95*	− 0.17*
Behavioral choice impulsivity—EDT
IV
CAI total	0.001	1.0	0.25*	0.25*	0.001 ( − 0.008 to 0.01)	4.00*	− 0.12*
Trauma	− 0.001	1.51	0.47*	0.47*	− 0.001 ( − 0.03 to 0.02)	3.70*	− 0.11*
Major life events	0.002	1.28	0.25	0.25	0.003 ( − 0.03 to 0.09)	3.93*	− 0.17*
Recent life events	0.005	0.59	0.55*	0.54*	0.003 ( − 0.02 to 0.05)	4.15*	− 0.17*
Chronic stressors	0.004	0.41	0.18*	0.18	0.002 ( − 0.02 to 0.03)	4.38*	− 0.16*
Behavioral response impulsivity—GNG
IV
CAI total	− 0.12	0.02	0.29*	0.29*	− 0.002 ( − 0.03 to 0.007)	3.90*	− 0.11*
Trauma	− 0.24	0.02	0.47*	0.48*	− 0.005 ( − 0.04 to 0.01)	3.57*	− 0.10*
Major life events	− 0.60	0.005	0.29	0.29	− 0.003 ( − 0.08 to 0.04)	3.94*	− 0.16*
Recent life events	0.03	0.001	0.55*	0.55*	0.001 ( − 0.02 to 0.03)	4.18*	− 0.16*
Chronic stressors	0.03	− 0.001	0.18*	0.18*	0.001 ( − 0.01 to 0.01)	4.44*	− 0.15*

Notes: IV = independent variable (i.e. CAI total, trauma, major life events, recent life events, chronic stressors); M = mediator (i.e. self-reported impulsivity, choice impulsivity, response impulsivity); DV = dependent variable (AUDIT). The total effect is the effect of the IV on the DV without including the mediators in the model. The direct effect is the effect of the IV on the DV, controlling for the effects of the mediators. The indirect effect is the effect of the IV on the DV via the mediator. Gender and IQ were included as covariates in all analyses. *Denotes significance level of p < 0.05.

Table III.  Mediation of association of stress with drinking behavior by self-reported non-planning, attentional, and motor impulsivity, with gender and IQ as covariates.

	Effect of IV on M (a)	Effect of M on DV (b)	Total effect (c)	Direct effect (c′)	Indirect effect (a × b) (95% CI)	Gender on DV	IQ on DV
Non-planning impulsivity—BIS-11
IV
CAI total	0.19*	0.25*	0.29*	0.24*	0.05* (0.01–0.11)	3.78*	− 0.10
Trauma	0.26*	0.26*	0.47*	0.40*	0.07* (0.02–0.14)	3.51*	− 0.09
Major life events	0.74*	0.34*	0.29	0.04	0.25* (0.09–0.53)	3.63*	− 0.14*
Recent life events	0.29*	0.30*	0.55*	0.47*	0.09* (0.02–0.23)	3.90*	− 0.14*
Chronic stressors	0.16*	0.31*	0.18*	0.13	0.05* (0.01–0.11)	4.04*	− 0.14*
Attentional impulsivity (BIS)
IV
CAI total	0.19*	0.38*	0.29*	0.22*	0.07* (0.03–0.13)	4.09*	− 0.14*
Trauma	0.24*	0.39*	0.47*	0.38*	0.10* (0.04–0.17)	3.85*	− 0.13*
Major life events	0.43*	0.47*	0.29	0.09	0.20* (0.01–0.50)	4.07*	− 0.18*
Recent life events	0.42*	0.42*	0.55*	0.38*	0.18* (0.08–0.33)	4.23*	− 0.18*
Chronic stressors	0.21*	0.44*	0.18*	0.09	0.09* (0.04–0.18)	4.30*	− 0.18*
Motor impulsivity (BIS)
IV
CAI total	0.25*	0.42*	0.29*	0.18*	0.11* (0.06–0.18)	3.81*	− 0.16
Trauma	0.37*	0.43*	0.47*	0.31*	0.16* (0.09–0.28)	3.61*	− 0.15*
Major life events	0.58*	0.54*	0.29	− 0.02	0.31* (0.14–0.55)	3.70*	− 0.21*
Recent life events	0.46*	0.48*	0.55*	0.34*	0.22* (0.10–0.40)	3.90*	− 0.20*
Chronic stressors	0.17*	0.51*	0.18*	0.09	0.09* (0.04–0.16)	4.00*	− 0.20*

Notes: IV = independent variable (i.e. CAI total, trauma, major life events, recent life events, chronic stressors); M = mediator (i.e. non-planning impulsivity, attentional impulsivity, motor impulsivity); DV = dependent variable (AUDIT). The total effect is the effect of the IV on the DV without including the mediators in the model. The direct effect is the effect of the IV on the DV, controlling for the effects of the mediators. The indirect effect is the effect of the IV on the DV via the mediator. Gender and IQ were included as covariates in all analyses. *denotes significance level of p < 0.05.

Table IV.  Mediation of effects of stress on hazardous drinking by self-reported, choice, and response impulsivity.

	Effect of IV on M (a)	Effect of M on DV (b)	Total effect (c)	Direct effect (c′)	Indirect effect (a × b) (95% CI)
Self-reported impulsivity—BIS-11
IV
CAI total	0.57*	0.05*	0.08*	0.05*	0.03* (0.01–0.05)
Trauma	0.80 *	0.05*	0.10*	0.06	0.04* (0.02–0.08)
Major life events	1.60*	0.06*	0.07	− 0.02	0.10* (0.04–0.19)
Recent life events	1.09*	0.05*	0.20*	0.16*	0.06* (0.02–0.11)
Chronic stressors	0.46*	0.06*	0.05*	0.03	0.03* (0.01–0.05)
Behavioral choice impulsivity—EDT
IV
CAI total	− 0.001	0.47	0.07*	0.07*	− 0.001 ( − 0.01 to 0.002)
Trauma	− 0.003	0.59	0.10*	0.10	− 0.002 ( − 0.02 to 0.003)
Major life events	− 0.002	0.38	0.06	0.07	− 0.001 ( − 0.03 to 0.01)
Recent life events	0.004	0.14	0.20*	0.20*	0.001 ( − 0.008 to 0.02)
Chronic stressors	0.003	0.13	0.05*	0.05*	0.001 ( − 0.01 to 0.008)
Response impulsivity—GNG
IV
CAI total	− 0.15	0.02	0.08*	0.08*	− 0.002 ( − 0.02 to 0.002)
Trauma	− 0.24	0.01	0.10*	0.10*	− 0.01 ( − 0.05 to 0.01)
Major life events	− 0.78	0.01	0.07	0.08	− 0.008 ( − 0.05 to 0.01)
Recent life events	− 0.07	0.01	0.20*	0.20*	− 0.001 ( − 0.02 to 0.006)
Chronic stressors	− 0.08	0.01	0.05*	0.05	− 0.001 ( − 0.009 to 0.002)

Notes: IV = independent variable (i.e. CAI total, trauma, major life events, recent life events, chronic stressors); M = mediator (i.e. self-reported impulsivity, choice impulsivity, response impulsivity); DV = dependent variable (AUDIT). The total effect is the effect of the IV on the DV without including the mediators in the model. The direct effect is the effect of the IV on the DV, controlling for the effects of the mediators. The indirect effect is the effect of the IV on the DV via the mediator. *Denotes significance at p < 0.05.