Cocaine craving and attentional bias in cocaine-dependent schizophrenic patients

Cocaine craving has been implicated as a major factor underlying addiction and drug relapse. From a cognitive viewpoint, craving may reflect, in part, attentional processing biased in favor of drug-related cues and stimuli. Schizophrenic individuals (SZ), however, abuse cocaine in high numbers but typically manifest baseline cognitive deficits that impair their ability to selectively allocate their attentional resources. In this study, we examined the relationship between attentional bias and craving in patients with cocaine dependence (COC; n=20), schizophrenic patients comorbid for cocaine dependence (COC+SZ; n=23), as well as two other comparison groups using a modified version of the Stroop test to include cocaine-relevant words. Results revealed that only the COC patients demonstrated Stroop interference on the cocaine-related words. Moreover, COC patients' attentional processing biases were significantly associated with their cocaine craving severity ratings. COC+SZ patients, in contrast, did not demonstrate Stroop interference and manifested significantly fewer craving symptoms than their COC counterparts. These results suggest that COC+SZ patients' inability to selectively encode their drug-use experience may limit and shape their subjective experience of craving cocaine and motivation for cocaine use.