Department of Psychology and Neuroscience, Temple University, Philadelphia, PA, United States.
Department of Psychology, University of Wisconsin-Madison, United States.
Brain Behav Immun. 2023 May;110:85-94. doi: 10.1016/j.bbi.2023.02.016. Epub 2023 Feb 21.
Substance use and depression frequently co-occur. Adolescence appears to be a vulnerable developmental period for increases in both substance use and depressive symptoms, often attributed to rapid maturation of reward and motivation systems. Another contributing factor could be inflammatory signaling, which has been associated with both substance use disorder and depression. Prior research indicates that an increase in inflammatory activity can cause physical and emotional malaise, which resembles depression, and the anhedonia and somatic symptoms could lead to substance use. This perspective that substance use is a type of self-medication in response to anhedonia and subjective experiencing of increased inflammatory physiology has not been investigated previously. To test these associations, we used path analysis to examine concurrent and prospective associations between three pro-inflammatory markers, specific depressive symptoms, and substance use frequency in a diverse sample of older adolescents. Participants completed repeated self-report measures of specific depressive symptoms (i.e., dysphoria, anhedonia, somatic concerns, negative cognitions, and functional difficulties) and substance use frequency. Blood was collected to quantify circulating levels of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP). This analysis showed an indirect effect of IL-6 and TNF-α levels on future substance use, but only via functional difficulties. Substance use also predicted future functional difficulties. Only anhedonia directly predicted future substance use frequency. These findings help to more precisely identify pathways through which inflammatory physiology and specific depressive symptoms synergistically confer risk for substance use.
物质使用和抑郁经常同时发生。青春期似乎是物质使用和抑郁症状增加的脆弱发展阶段，这通常归因于奖励和动机系统的快速成熟。另一个促成因素可能是炎症信号，它与物质使用障碍和抑郁症都有关。先前的研究表明，炎症活动的增加会导致身体和情绪不适，类似于抑郁，而快感缺失和躯体症状可能导致物质使用。这种观点认为，物质使用是一种对快感缺失和炎症生理增加的主观体验的自我治疗，以前尚未被研究过。为了检验这些关联，我们使用路径分析来检查在一个多样化的青少年样本中，三种促炎标志物、特定抑郁症状和物质使用频率之间的并发和前瞻性关联。参与者完成了对特定抑郁症状（即烦躁、快感缺失、躯体问题、消极认知和功能困难）和物质使用频率的重复自我报告测量。采集血液以定量循环白细胞介素 (IL)-6、肿瘤坏死因子-α (TNF-α) 和 C 反应蛋白 (CRP) 的水平。该分析显示 IL-6 和 TNF-α 水平对未来物质使用的间接影响，但仅通过功能困难。物质使用也预测了未来的功能困难。只有快感缺失直接预测了未来物质使用频率。这些发现有助于更准确地确定炎症生理和特定抑郁症状协同为物质使用带来风险的途径。
