Faculty Bibliography

Previous findings suggest that neuroadaptations downstream of D-1 dopamine (DA) receptor stimulation in nucleus accumbens (NAc) are involved in the enhancement of drug reward by chronic food restriction (FR). Given the high co-expression of D-1 and GluR1 AMPA receptors in NAc, and the regulation of GluR1 channel conductance and trafficking by D-1-linked intracellular signaling cascades, the present study examined effects of the D-1 agonist, SKF-82958, on NAc GluR1 phosphorylation, intracranial electrical self-stimulation reward (ICSS), and reversibility of reward effects by a polyamine GluR1 antagonist, 1-NA-spermine, in ad libitum fed (AL) and FR rats. Systemically administered SKF-82958, or brief ingestion of a 10% sucrose solution, increased NAc GluR1 phosphorylation on Ser845, but not Ser831, with a greater effect in FR than AL rats. Microinjection of SKF-82958 in NAc shell produced a reward-potentiating effect that was greater in FR than AL rats, and was reversed by co-injection of 1-NA-spermine. GluR1 abundance in whole cell and synaptosomal fractions of NAc did not differ between feeding groups, and microinjection of AMPA, while affecting ICSS, did not exert greater effects in FR than AL rats. These results suggest a role of NAc GluR1 in the reward-potentiating effect of D-1 DA receptor stimulation and its enhancement by FR. Moreover, GluR1 involvement appears to occur downstream of D-1 DA receptor stimulation rather than reflecting a basal increase in GluR1 expression or function. Based on evidence that phosphorylation of GluR1 on Ser845 primes synaptic strengthening, the present results may reflect a mechanism via which FR normally facilitates reward-related learning to re-align instrumental behavior with environmental contingencies under the pressure of negative energy balance

We conducted a randomized controlled trial of a sexual risk-reduction intervention targeting non-injection drug users (NIDUs) and members of their drug-use/sexual networks (N=270). The intervention was based primarily on the social-influencing approach, and was delivered in four sessions. Sexual risk behaviors were examined at baseline, and 3, 6, 9, and 12 months after the completion of the intervention using the vaginal equivalent episodes (VEE), a weighted sexual risk behavior index. VEE scores decreased in both the active and control conditions in the first six months post-intervention and continued to decline in the control group. However, in the active condition, VEE scores increased after the nine-month assessment and approached baseline levels by the 12-month assessment. There was no evidence of significant differences in high-risk sexual behaviors between the intervention and control conditions. Future studies are needed to improve behavioral interventions in this population.

BACKGROUND: Although attention deficit/hyperactive disorder (ADHD) is a common comorbidity in individuals who are diagnosed with substance use disorder (SUD), little data currently exist on the utility of screening tools in large samples of adults with SUD in inpatient treatment and the prevalence of ADHD in this population. The aims of this study were to assess the screen positive rate on the Adult ADHD Self Report Scale (ASRS) v.1.1 Screener in a large sample of adults being treated for SUD in a residential treatment facility (RTF) and to establish the imputed prevalence of adult ADHD. METHODS: Adults with SUD who were either newly admitted (abstinent for < 1 week) or in treatment in the RTF (abstinent < 3 months) were administered the ASRS v.1.1 Screener. Adults who screened positive on the ASRS v1.1 Screener (>or= 4/6 significant items) were then administered the Adult Clinician Diagnostic Scale (ACDS) v.1.2 to establish a diagnosis of ADHD and the positive predictive value (PPV) in this population. The imputed prevalence of adult ADHD was calculated based on the known rate of ADHD in the screened positive cohort and a calculated rate of ADHD in the screened negative sample based on prior studies of the ASRS v1.1 Screener in community-based and managed care samples. RESULTS: 1064 adults were screened via the ASRS v.1.1 Screener, with 92 screening positive (8.6% had >or= 4 significant items present). Fifty-three of those who screened positive were diagnosed as having adult ADHD (PPV = 57.6%). The imputed prevalence of adult ADHD in this population was 7.5%. CONCLUSIONS: The PPV for the ASRS v1.1 Screener for adult ADHD in this sample of adults with SUD was similar to that observed in a prior study of a managed care sample, but was somewhat less than that observed in the community-based sample. The imputed prevalence rate for comorbid ADHD in this study of adults with SUD in a RTF was similar to, but slightly lower than the prevalence rate of ADHD in patients with any SUD observed in the community-based sample

Substance use disorders are highly prevalent in the United States and cause considerable damage to our society. They are underrecognized and undertreated despite a vast body of literature demonstrating the efficacy of treatment using both psychosocial and psychopharmacological modalities. For the last decade, research and progress into the biological basis of the addictive process has led to a rapidly growing number of pharmacological agents used to interrupt the addictive process at its various stages such as the initiation of substance abuse, the transition from abuse to dependence, and the prevention of drug reinstatement or relapse. Food and Drug Administration-approved medications exist for nicotine, alcohol, and opioid use disorders, and progress is being made to develop agents for stimulant use disorders. Regarding nicotine use disorders, nicotine replacement therapies,bupropion and varenicline, have Food and Drug Administration approval, and future options exist with endocannabinoid antagonists and immune therapy. Aversive agents, opiate antagonists, and glutamate based interventions are currently approved to treat alcohol use disorders with future promise with GABAergic, serotonergic, and endocannabinoid system agents. Opiate addiction is treated by approved agonist and antagonist mu-opioid medications with the future potential for agents that can modulate the stress systems and the iboga alkaloids. Although no pharmacotherapies are currently approved for cocaine addiction, promising lines of research include agents that affect dopaminergic, GABAergic, serotonergic,and glutamatergic systems as well as the promise for immune therapies

Addiction is increasingly understood as a neurobiological illness where repetitive substance abuse corrupts the normal circuitry of rewarding and adaptive behaviors causing drug-induced neuroplastic changes. The addictive process can be examined by looking at the biological basis of substance initiation to the progression of substance abuse to dependence to the enduring risk of relapse. Critical neurotransmitters and neurocircuits underlie the pathological changes at each of these stages. Enhanced dopamine transmission in the nucleus accumbens is part of the common pathway for the positively rewarding aspects of drugs of abuse and for initiation of the addictive process. F-Aminobutyric acid,opioid peptides, serotonin, acetylcholine, the endocannabinoids, and glutamate systems also play a role in the initial addictive process. Dopamine also plays a key role in conditioned responses to drugs of abuse, and addiction is now recognized as a disease of pathological learning and memory. In the path from substance abuse to addiction, the neurochemistry shifts from a dopamine-based behavioral system to a predominantly glutamate-based one marked by dysregulated glutamate transmission from the prefrontal cortex to the nucleus accumbens in relation to drug versus biologically oriented stimuli. This is a core part of the executive dysfunction now understood as one of the hallmark features of addiction that also includes impaired decision making and impulse dysregulation.Understanding the neurobiology of the addictive process allows for a theoretical psychopharmacological approach to treating addictive disorders,one that takes into account biological interventions aimed at particular stages of the illness