Electrophysiological indexes for impaired response inhibition and salience attribution in substance (stimulants and depressants) use disorders: A meta-analysis.

The impairment of inhibitory control and reward system is the core feature underlying substance use disorder (SUD). Previous studies suggested that it can be regarded as impaired response inhibition and salience attribution syndrome (iRISA). The neural substrates of the two deficit functions were widely investigated in neuroimaging studies, and the impaired prefrontal cortex, limbic-orbitofrontal network, and fronto-insular-parietal network were observed. Previous Event-related potential (ERP) studies were also conducted to explore EEG indexes related to abnormal brain function. In the current meta-analysis, we aimed to explore the consistency of ERP indexes that can reflect the two aberrant processes: P300/slow potential (SP) for salience attribution and Error-related negativity (ERN)/Nogo-N200/Nogo-P300 for inhibitory control and conflict monitoring. Subgroup analyses for drug type and drug use conditions were also conducted. According to the 60 research studies, we found significantly enhanced drug-cue-induced P300 amplitude and attenuated Nogo-N200 amplitude in SUD individuals relative to Healthy control (HC), which supports the dual model. Moreover, the drug-cue-induced P300 displayed time-dependence recovery, suggesting a potential index for treatment evaluation. In conclusion, drug-cue-induced P300 and Nogo-N200 demonstrated high consistency, and the drug-cue-induced P300 can be used to track the changes of functional recovery for SUD. The integration of the two ERP components could be regarded as a potential biomarker for SUD, which may provide a new insight for clinical treatment and investigation.

Impaired Cognitive Empathy in Outpatients with Chronic Musculoskeletal Pain: A Cross-Sectional Study.

Background: In recent years, a growing number of researchers showed significant interest in psychological and social interventions to manage chronic musculoskeletal (MSK) pain. Cognitive and emotional empathy is an attractive and valuable sociopsychological factor that may provide protection and resilience against chronic MSK pain. However, its effect on outpatients remains underexplored. Objective: To compare the empathy ability between chronic MSK pain outpatients and healthy controls and explore the relationship between cognitive/emotional empathy and chronic pain. Methods: Patients with chronic MSK pain (n = 22) and healthy controls (n = 26) completed the pain assessment and empathy ability task, utilizing a multidimensional empathy assessment tool with satisfactory reliability and validity (i.e., the Chinese version of the Multifaceted Empathy Test (MET-C)). Results: The data indicated that the chronic MSK pain outpatients had impaired cognitive empathy (i.e., lower squared cognitive empathy accuracy: Student's t = -2.119, P = 0.040, and longer task completion time: Student's t = 3.382, P = 0.002) compared to healthy controls, and cognitive empathy was negatively correlated with pain intensity (r = -0.614, P = 0.002). Further, the impaired cognitive empathy was present in identifying positive, but not negative emotions. Conclusion: These results indicate that chronic MSK pain is associated with impaired empathy ability. Our studies contribute to offering a potential direction for developing psychosocial interventions to treat chronic MSK pain.

Brief Report: Predictors of Relapse for Patients With Dextromethorphan Dependence.

BACKGROUND AND OBJECTIVES: The recreational use of dextromethorphan (DXM) triggers dependence. The pattern and clinical predictors of relapse are unclear. METHODS: Here, we retrospectively analyzed the clinical information of 28 patients with DXM dependence (20 males and 8 females). RESULTS: The mean age at admission was 25.89 years (standard deviation [SD] = 7.84), and the average duration of DXM abuse was 24.96 months (SD = 17.40). The relapse rates at 1 month, 3 months, 6 months, and 1 year were 7.14%, 25%, 71.43%, and 89.29%, respectively. Depression and anxiety status at baseline were positive predictors of relapse (r = -.539, P = .006, R2 = 0.290; r = -.449, P = .024, R2 = 0.202, respectively). DISCUSSION AND CONCLUSIONS: Our results suggest that patients with DXM dependence are at high risk of relapse and that measuring affective disturbance is important for predicting the outcomes of their treatment. SCIENTIFIC SIGNIFICANCE: This study first identified a high relapse rate among patients with DXM dependence and found that the baseline depression and anxiety status was correlated with the time length of relapse. These findings not only warn us of the vulnerability of DXM-dependent relapse but also reveal the importance of measuring affective disturbance in relapse prevention. (Am J Addict 2020;00:00-00).