In the present study, we observed that individuals with self-reported family histories of alcohol related problems were more impulsive on the IMT and GoStop, measures of response initiation and response inhibition impulsivity, but there were no significant effects of FHAP status on TCIP or SKIP performance, measures of consequence sensitivity impulsivity. We also observed no group differences in self-reported impulsivity on the BIS-11. These results suggest that response initiation and response inhibition impulsivity may be generally increased across individuals with a broad range of family histories of alcohol use disorders. In contrast increased consequence sensitivity impulsivity may be more apparent in individuals who are at greater risk for developing alcohol and drug use disorders, or they may be increased as a consequence of heavy alcohol or drug use.
This study is the first to examine four distinct measures of impulsivity within the same sample of individuals who were at risk for developing alcohol use disorders based on family history. Our results are consistent with previous studies that have examined the effects of FHA status on similar measures separately despite those studies using samples of different ages and varied methods for classifying FHA status (Crean et al., 2002
; Nigg et al., 2006
; Petry et al., 2002
; Saunders et al., 2008
). The present study found FHAP+ individuals were more impulsive on both the IMT and GoStop tasks, which together with previous studies suggests that increased response initiation and response inhibition impulsivity may be a relatively robust characteristics in individuals at risk based on family history (Nigg et al., 2006
; Saunders et al., 2008
). Additionally, the lack of significant differences in impulsive choice on the TCIP and SKIP are consistent with previous studies finding small or no FHA associated differences in relative preferences for immediate and delayed rewards (Acheson et al., in press
; Crean et al., 2002
; Herting et al., 2010
; Petry et al., 2002
) and suggest that consequence sensitivity impulsivity is not prominently affected by FHA status.
The present findings should be considered in the context of the participant classification and recruitment strategy. The positive family history group only had to have at least one major, alcohol-related problem in at least one biological parent, and this criteria likely resulted in relatively heterogeneous backgrounds of parental alcohol use disorders in this sample. Furthermore, participants in this study were adults with no histories of alcohol or other drug use disorders, and while some of the younger participants may still develop drug or alcohol use problems, this seems less likely for the older participants in the study. Consequently, it is possible our selection criteria excluded potential FHAP+ participants most strongly predisposed to alcohol and drug problems because they would already be afflicted. The fact that significant increases in response initiation and response were still observed suggest that increases in these forms of impulsivity are strongly associated with family history of alcohol use disorders and may be persistent phenotypical characteristics of this population. However the lack of significant differences on consequence sensitivity impulsivity in the present sample and previous studies do not rule out a prominent role for consequence sensitivity impulsivity in risk for alcohol use disorders. As alcohol dependence is associated with increased consequence sensitivity impulsivity (Mitchell et al., 2005
; Petry, 2001
), it is possible that increased consequence sensitivity impulsivity may be increased in individuals more strongly predisposed to alcohol and drug use disorders (individuals who may have been excluded from this study because of the age group recruited). For instance, consequence sensitivity may be increased in individuals with more serious and denser family histories of alcohol use disorders or additional risk factors such as high behavioral undercontrol (Acheson et al., in press
; Sher et al., 2004
; Sher and Trull, 1994
). Alternatively, it is possible that increased consequence sensitivity impulsivity may develop as alcohol and other substance use disorders progress.
It is possible that increased response initiation and response inhibition impulsivity relates to risk for alcohol use disorders by an association with the trait of urgency, or the tendency to act rashly when experiencing extremely negative or positive moods (Billieux et al., 2010
; Dick et al., 2010
). Urgency was one of four distinct impulsivity-related traits identified from a factor analysis performed on multiple self-report measures of personality and impulsivity administered to a large sample of undergraduate students (Whiteside and Lynam, 2001
), and subsequent research has found that high levels of self-reported urgency are associated alcohol and drug use disorders (Verdejo-Garcia et al., 2007
; Whiteside and Lynam, 2003
). It has been proposed that high response initiation and inhibition impulsivity may underlie urgency (Bechara and Van Der Linden, 2005
), and there is emerging empirical support for this assertion (Billieux et al., 2010
; Gay et al., 2008
). Although we observed no group differences in self-reported impulsivity (BIS-11), it is possible we would have detected group differences in self-reported urgency had we administered the full UPPS Impulsive Behavior Scale (Whiteside and Lynam, 2001
). Therefore, high response initiation and response inhibition impulsivity may increase risk for alcohol use disorders by making individuals more emotionally reactive and thereby making alcohol misuse more likely. Alternatively, high response initiation and response inhibition impulsivity may be less directly related to problem alcohol use and instead contribute to the general, relatively subtle cognitive impairments associated with FHA (Corral et al., 2003
; Deckel, 1999
; Stevens et al., 2003
), and these cognitive impairments may be primarily responsible for biasing these individuals towards alcohol and drug use disorders as well other maladaptive behaviors. More research is needed, particularly in at risk and alcohol and drug abusing populations, to better understand relationships between response initiation and inhibition impulsivity, urgency, other behavioral and self-report measures of impulsivity, and alcohol and drug use disorders.