Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress

In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse

Will cervical screening remain cost-effective in women offered the next generation nonavalent HPV vaccine? Results for four developed countries

A next generation nonavalent human papillomavirus (HPV) vaccine ("HPV9 vaccine") is being introduced in several countries. The aims of this study were to evaluate whether cervical screening will remain cost-effective in cohorts offered nonavalent vaccines and if so, to characterize the optimal number of screening tests. We used a dynamic model of HPV vaccination and cervical screening to evaluate the cost-effectiveness of strategies involving varying numbers of primary HPV tests per lifetime for cohorts offered the nonavalent vaccine as 12 year-olds. For each of four countries-the USA, New Zealand (NZ), Australia and England-we considered local factors including vaccine uptake rates (USA/NZ uptake ∼50%; Australia/England uptake >70%), attributable fractions of HPV9-included types, demographic factors, costs and indicative willingness-to-pay (WTP) thresholds. Extensive probabilistic sensitivity analysis was performed. We found that, in the USA, four screens per lifetime was the most likely scenario, with 34% probability of being optimal at WTP US$50,000/LYS, increasing to 84$100,000/LYS. In New Zealand, five screens per lifetime was the most likely scenario, with 100% probability of being optimal at NZ$42,000/LYS, given the assumptions used. In Australia, two screens per lifetime was the most likely scenario, with 62$50,000/LYS. In England, four screens per lifetime was the most likely scenario, with 32% probability of being optimal at GB£20,000/LYS, increasing to 96% probability at GB£30,000/LYS. We conclude that some cervical screening will remain cost-effective, even in countries with high vaccination coverage. However, the optimal number of screens may vary between countries

Evidence for a psychotic posttraumatic stress disorder subtype based on the National Comorbidity Survey

Purpose This study assessed the distribution of posttraumatic stress disorder (PTSD) symptoms and psychosis indicators among a large sample of individuals with a lifetime diagnosis of PTSD. The identification of a psychotic PTSD subtype was also predicted. Method Using data from the National Comorbidity Survey a latent class analysis was conducted on the PTSD symptoms of intrusion, avoidance, and hyperarousal and the psychosis hallucination and delusion indicators. Results Results indicated four latent classes, two of which had relatively high probabilities of endorsing the hallucination and delusion indicators. These classes were associated with a broad range of traumatic experiences. One particular class had high probabilities of endorsing both the psychosis indicators and the PTSD symptoms and was associated with a broad range of comorbid psychiatric disorders. Conclusion There was a candidate class that met the characteristics expected to be evident in a psychotic PTSD subtype.</p