Gunn Rachel L, Jackson Kristina M, Borsari Brian, Metrik Jane
1Center for Alcohol and Addiction Studies, Brown University School of Public Health, Providence, RI 02903 USA.
2San Francisco VA Medical Center, San Francisco, California 94121 USA.
Borderline Personal Disord Emot Dysregul. 2018 May 16;5:10. doi: 10.1186/s40479-018-0087-7. eCollection 2018.
To goal of this study was to better understand mechanisms underlying associations between Major Depressive Disorder (MDD) and marijuana use and problems. Specifically, it was hypothesized that negative urgency (NU), the tendency to act rashly while experiencing negative mood states, would uniquely (compared to other impulsivity traits: positive urgency, sensation seeking, premeditation, and perseverance) account for the relationship between MDD and marijuana use and problems.
Data were collected from a sample ( = 357) of veterans ( age = 33.63) recruited from a Veterans Affairs hospital who used marijuana at least once in their lifetime. Participants completed the SCID-NP to assess MDD, a marijuana problems scale, a Time-Line Follow-back to assess six-month marijuana use, and the UPPS-P Impulsive Behavior Scale for impulsivity.
Path analysis was conducted using bootstrapped ( = 20,000) and bias-corrected 95% confidence intervals (CIs) to estimate mediation (indirect) effects, controlling for age, sex, and race. Analyses revealed a significant direct effect of MDD on NU and NU on marijuana problems. Regarding mediational analyses, there was a significant indirect effect of MDD on marijuana problems via NU. The direct effect of MDD on marijuana problems was reduced, but remained significant, suggesting partial mediation. No other impulsivity scales accounted for the relationship between MDD and marijuana problems. In predicting marijuana use, there were no significant indirect effects for any impulsivity traits, including NU, despite significant bivariate associations between use and NU and MDD.
Results suggest that high levels of NU may partially explain associations between MDD and marijuana problems, but not marijuana use. No other facets of impulsivity accounted for the relationship between MDD and marijuana use or problems, underscoring the specificity of NU as a putative mechanism and the importance of assessing NU in treatment settings.
本研究的目的是更好地理解重度抑郁症（MDD）与大麻使用及问题之间关联的潜在机制。具体而言，研究假设消极紧迫性（NU），即在经历消极情绪状态时冲动行事的倾向，将独特地（与其他冲动性特质：积极紧迫性、寻求刺激、预谋和毅力相比）解释MDD与大麻使用及问题之间的关系。
数据收集自一家退伍军人事务医院招募的退伍军人样本（n = 357，年龄 = 33.63岁），这些退伍军人一生中至少使用过一次大麻。参与者完成了用于评估MDD的SCID-NP、大麻问题量表、用于评估六个月大麻使用情况的时间线回溯法，以及用于评估冲动性的UPPS-P冲动行为量表。
使用自抽样法（n = 20,000）和偏差校正的95%置信区间（CIs）进行路径分析，以估计中介（间接）效应，并控制年龄、性别和种族。分析显示MDD对NU有显著直接效应，NU对大麻问题有显著直接效应。关于中介分析，MDD通过NU对大麻问题有显著间接效应。MDD对大麻问题的直接效应有所降低，但仍显著，表明存在部分中介作用。没有其他冲动性量表能解释MDD与大麻问题之间的关系。在预测大麻使用方面，尽管使用与NU和MDD之间存在显著的双变量关联，但任何冲动性特质（包括NU）均无显著间接效应。
结果表明，高水平的NU可能部分解释MDD与大麻问题之间的关联，但不能解释大麻使用情况。没有其他冲动性方面能解释MDD与大麻使用或问题之间 的关系，这凸显了NU作为一种假定机制的特异性以及在治疗环境中评估NU的重要性。
