The anhedonia-like behaviors following about 1-week withdrawal from morphine were examined in the present study. Male rats were pretreated with either a binge-like morphine paradigm or daily saline injection for 5 days. Three types of natural reward were used, food reward (2.5, 4, 15, 30, 40, and 60% sucrose solutions), social reward (male rat) and sexual reward (estrous female rat). For each type of natural stimulus, consummatory behavior and motivational behaviors under varied testing conditions were investigated. The results showed that the morphine-treated rats significantly reduced their consumption of 2.5% sucrose solution during the 1-h consumption testing and their operant responding for 15, 30, and 40% sucrose solutions under a fixed ratio 1 (FR1) schedule. However, performance under a progressive ratio (PR) schedule increased in morphine-treated rats reinforced with 60% sucrose solution, but not in those reinforced with sucrose concentrations lower than 60%. Pretreatment with morphine significantly decreased the male rats' ejaculation frequency (EF) during the 1-h copulation testing, and impaired the maintenance of appetitive motivations to sexual and social stimuli under a free-approach condition. Moreover, the morphine-treated rats demonstrated a diminished motivation to approach social stimulus in the effort-based appetitive behavior test but showed a remarkable increase in motivation to approach sexual stimulus in the risky appetitive behavior test. These results demonstrated some complex motivated behaviors following about 1 week of morphine withdrawal: (1) The anhedonia-like behavior was consistently found in animals withdrawn from morphine. However, for a given reward, there was often a dissociation of the consummatory behaviors from the motivational behaviors, and whether the consummatory or the motivational anhedonia-like behaviors could be discovered heavily depended on the type and magnitude of the reward and the type of testing task; (2) These anhedonia-like behaviors coexisted with a craving for the high-incentive reward which was evidenced by the increased PR performance for the 60% sucrose solution and the heightened risky appetitive behavior for the sexual stimulus. The craving for the high-incentive reward alongside with the impaired inhibitory control in drug-withdrawn subjects might form one of psychological mechanisms underlying drug relapse after withdrawal.

After traumatic events, children with different types of attentional biases produce different psychological reactions with the help of the rumination process. A sample of 909 middle school students was taken from the Yunnan Ludian earthquake-affected area. Measurement scales of the Chinese version of the Attention to Positive and Negative Information Scale (APNI), the Chinese version of the Children's Revised Impact of Event Scale (CRIES), and the Revised Post-traumatic Growth Inventory for Children (PTG-C) were used to assess the attentional bias, risk of post-traumatic stress disorder (PTSD), and post-traumatic growth (PTG), respectively. The effect of self-reported attention bias was explored by using a structural equation model and bias-corrected bootstrap test on children's psychological reaction after trauma. The results show that there is a positive relationship between self-reported negative attentional bias and PTSD symptoms partially mediated by intrusive rumination and the negative relationship between self-reported positive attentional bias and PTSD symptoms. On the other hand, the relationship between self-reported positive attentional bias and PTG was positive and partially mediated by deliberate rumination. Furthermore, intrusive rumination did not affect PTG indirectly but mediated the relation of deliberate rumination.

No abstract