Social rank and cocaine dependence: Estimates for the United States, 2005–2013

s / Drug and Alcohol Dependence 156 (2015) e102–e182 e155 Methods: Rats implanted with an electrode into the medial forebrain bundle were trained to hold a lever for 4 s to obtain an intracranial self-stimulation (ICSS) reward, and to release the lever immediately after they had obtained a reward. As for estimating impulsivity, a number of reward gain per min (RGR) through 4 s lever-holding behavior is regarded to reflect impulsivity related to “action restraint”, whereas a time for releasing the lever (TFR) after the rats had obtained a reward is regarded to reflect impulsivity related to “action cancellation”. Results: Acute subcutaneous administration of NCT at 0.4mg/kg decreased TFR, whereas mecamylamine-precipitated NCT-withdrawal increased TFR, which may indicate that NCT withdrawal increased impulsivity related to “action cancellation”. A D3/D3 receptor agonist pramipexole (PPX), which has been reported to cause impulse-control disorders, decreased RGR and increased TFR, indicating that PPX increased both types of impulsivity. Subcutaneous administration of NCT at 0.4 and 0.8mg/kg decreased TFR, whereas intragastric administration of paroxetine (SSRI) at 10 and 30mg/kg increased RGR in the PPX-treated rats. Conclusions: These results indicated that NCT improved impulsivity related to “action cancellation”, whereas paroxetine improved impulsivity related to “action restraint”. Therefore,NCT is suggested to have a potential to show therapeutic effect on impulsivity through a different mechanism from that of paroxetine. Financial support: The Ministry of Education, Culture, Sports, Science and Technology of Japan (No. 23591682), the Smoking Research Foundation. http://dx.doi.org/10.1016/j.drugalcdep.2015.07.421 Social rank and cocaine dependence: Estimates for the United States, 2005–2013 Abiy M. Mohammed, Jim C. Anthony Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, United States Aims: Past research indicates downward social rank shift of cocaine use, with odds of cocaine use becoming greater at lower social rank levels. Here, we seek estimates of cocaine dependence transition probabilities (CDTP) in relation to indicators of social rank, beginning with poverty level gradients. Methods:Data are fromUnited States National Surveys onDrug Use and Health, 2005–2013, with nationally representative samples and standardized computer-assisted assessment modules and n>50,000 persons each year (US; NSDUH; SDA samples). US Census Bureau poverty rank is based on participant age, total family income, family size, and number of children in the household. Estimates areproduced for eachyear,withmeta-analysis used to create a summary estimate. Results: In meta-analysis, no statistically robust variation in CDTP estimates can be seen in relation to this social rank gradient. For those in poverty, CDTP is an estimated 4.7% (95% CI =2.3, 7.2). Estimatedmiddle-incomeCDTP is 4.6% (95%CI =2.4, 6.9). Estimated higher income CDTP is 6.7% (95% CI =4.2, 9.2). Conclusions: Whereas there now might be an inverse social rank gradient in incidence or prevalence of cocaine use, this gradient cannot be seen in estimates for theprobability ofmaking a rapid transition from onset of cocaine use to onset of cocaine dependence. These epidemiological estimates underscore the importance of drawing distinctions between cocaine use per se and cocaine dependence per se. Epidemiological patterns in the occurrence of cocaine use might well differ from epidemiological patterns of cocaine dependence. Financial support: NIDA T32DA021129 (AMM); K05DA015799 (JCA). http://dx.doi.org/10.1016/j.drugalcdep.2015.07.422 A higher hill to climb! Older cocaine-addicted patients viewing 500ms cocaine cues have reduced activation of modulatory circuits and increased activation of motivational circuits Zachary A. Monge1, K. Jagannathan1, Jesse Suh1,2, Ronald Ehrman1,2, Ze Wang1, Teresa Franklin1, Reagan R. Wetherill 1, Kimberly A. Young1, Michael J. Gawrysiak1,2, Daniel Langleben1,2, Charles P. O’Brien1,2, Anna Rose Childress1 1 Psychiatry, University of Pennsylvania, Philadelphia, PA, United States 2 VA VISN 4 MIRECC, Philadelphia, PA, United States Aims: Chronic cocaine use may exacerbate the effects of aging on the brain (e.g., prefrontal cortex atrophy). Here, we examined the associationbetween age and the early brain response to cocaine cues in a sample of cocaine-dependent patients. We hypothesized that older participants viewing 500ms cocaine cues would have either, decreased activation of prefrontal modulatory (“STOP!”) regions, or increased activation of mesolimbic dopamine (“GO!”) regions, or both. Methods: Cocaine-dependent patients (n=38) were scanned with event-related BOLD fMRI during exposure to brief (500ms) evocative (cocaine, sexual, aversive) vs. neutral cues. The age of the participants (range: 34–60 years) was then used as a single regressor in a pre-planned (cocaine-neutral) cue contrast examining the first and second halves of the task separately. In order to examine if the age-brain correlations were due to the older participants using cocaine formore years than the younger participants, agewas correlated with years of cocaine use. Results: For the first half of the task, age correlated positively with the brain response to the cocaine cues in several reward-relevantnodes: bilateral insula, right amygdala, andmedial orbitofrontal cortex (OFC; 2′′t′′6). For the secondhalf of the task, age correlated negatively with several prefrontal modulatory regions: bilateral superior and middle frontal gyri, frontal pole, lateral OFC, subgenual cingulate cortex, and paracingulate gyrus (2′′t′′6). Furthermore, age did not correlate with years of cocaine use (r=0.05, p=0.8). Conclusions: Here, we demonstrated that older cocainedependent patientsmay be bothmore sensitive to themotivational “pull” of reward cues and less able to modulate this “pull” – giving them a “higher hill” to climb towards recovery. Financial support: Commonwealth of Pennsylvania CURE Addiction Center of Excellence; NIH/NIDA (P5012756; T32DA028874); VA VISN 4 MIRECC. http://dx.doi.org/10.1016/j.drugalcdep.2015.07.423