Alcohol-Attentional Bias in Alcohol-Dependent and Cocaine-Dependent Patients

Background: Substance-related attentional bias refers to the reactivity to substance-related cues. This attentional bias to drugs has been examined in different addictive disorders such as cocaine, alcohol or tobacco dependence. There is extensive evidence regarding the attentional bias to alcohol-related cues in Alcohol Dependent (AD) patients. Furthermore, there is evidence regarding the higher attention bias to cocaine-related cues in Cocaine Dependent (CD) subjects after the exposure to alcohol consumption. However, there are still no data on the potential attentional bias to alcohol-related cues in patients diagnosed with CD. Objectives: we aimed to assess attentional bias in a sample of alcohol and cocaine users with a visual probe task. Material and methods: We used a sample of 35 AD patients, 30 CD patients and a control group formed by 35 healthy volunteers. Moreover, and to further study alcohol attentional bias in CD subjects, we divided this group in terms of their history of alcohol consumption. All subjects were examined using the visual probe task, in order to study the attentional bias to alcohol-related cues. Results: The patients that showed the greater attentional bias to alcohol-related cues were the AD subjects, followed by the CD patients and finally by controls. AD and CD exhibited lower reaction times to alcoholcongruent condition compared to the alcohol-incongruent, whereas in controls the opposite effect was found. Discussion: Our results indicated that although attentional bias to alcohol-related cues was clearly found in AD and CD patients, these data are in accordance with the hypothesis about the fact that cocaine dependence increases the attentional bias to other drugs, such as alcohol. Central Morales-Muñoz et al. (2014) Email: J Subst Abuse Alcohol 2(2): 1013 (2014) 2/6 (CS), the CS comes to elicit a Conditioned Response (CR), such as physiological arousal or craving to use the substance. One consequence of classical conditioning is cues orient attention towards a predictive CS when encountered [5-7]. Therefore, when conditioning occurs and a substance of abuse is the US, one would expect that substance-related stimuli would attract the user’s attention [3]. Researchers have found attentional bias for substance-related stimuli (presented verbally, pictorially, or as in vivo exposure) in users of different substances such as cocaine [8], alcohol [9] and tobacco [10]. Alcohol ingestion, for instance, increases this attentional bias to alcohol-associated stimuli [11]. In heavy social drinkers, alcoholassociated stimuli grab attention [1,12] and increase both the urge to drink alcohol and the amount of alcohol intake However, previous studies in individuals with alcohol dependence have shown that, unlike social drinking controls, individuals with alcohol dependence exhibit avoidance for alcohol-related visual stimuli in a dot probe detection task. Avoidance suggests the finding of a negative bias whereby the patients allocate their attention to the control stimuli and away from the alcohol-related stimuli [12]. Nikolaou et al found that attentional bias to alcohol related stimuli was reliably observed at the low, but not at the high alcohol dose when compared with placebo [13]. Thus, despite there are several studies related to attentional bias in alcohol, the underlying cognitive processes remain unknown. Alcohol and cocaine are used in higher quantities with concomitant use than when either of the substances are used individually [14], and it is proven by a wide variety of researches that cocaine and alcohol combination produces additive psychological and physiological effects [15]. Therefore, and given that dopamine activity in the mesolimbic pathway is hypothesised to be responsible for incentive salience attribution and attentional bias [3,16], acute administration of drugs that increase dopaminergic activity should lead to increases in attentional bias for any drug-related cues. In addition, Montgomery et al found increased attentional bias for cocaine cues following preload with alcohol in regular cocaine users, by means of a visual probe task [17]. In cocaine attentional bias, researches using the cocaine emotional Stroop task showed that subjects who use cocaine had slower reaction time compared to controls [8]. Other authors also observed that regions implicated in the general orientation of attention also showed significantly increased activation under low load in presence of the alcoholassociated stimuli compared to the neutral stimuli, and this observation extends to those findings with cocaine-related stimuli [17]. Now then, if cocaine consumption is associated with alcohol consumption in clinical samples and in general population [18], it can be hypothesized that cocaine may increase attentional bias alcohol-related cues in subjects without any alcohol use disorder (e.g., abuse or dependence). The present study sought to assess attentional bias in a sample of alcohol and cocaine users with a visual probe task. We hypothesized that Alcohol Dependent (AD) patients and cocainedependent subjects would show greater attentional bias for alcohol stimuli compared to controls. METHODS