From the Department of Epidemiology, Boston University School of Public Health, Boston, MA.
Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
Epidemiology. 2022 Mar 1;33(2):295-305. doi: 10.1097/EDE.0000000000001449.
Previous studies of the effect of interaction between psychiatric disorders on suicide have reported mixed results. We investigated the joint effect of depression and various comorbid psychiatric disorders on suicide.
We conducted a population-based case-cohort study with all suicide deaths occurring between 1 January 1995 and 31 December 2015 in Denmark (n = 14,103) and a comparison subcohort comprised of a 5% random sample of the source population at baseline (n = 265,183). We quantified the joint effect of pairwise combinations of depression and major psychiatric disorders (e.g., organic disorders, substance use disorders, schizophrenia, bipolar disorder, neurotic disorders, eating disorders, personality disorders, intellectual disabilities, developmental disorders, and behavioral disorders) on suicide using marginal structural models and calculated the relative excess risk due to interaction. We assessed for the presence of competing antagonism for negative relative excess risk due to interactions.
All combinations of depression and comorbid psychiatric disorders were associated with increased suicide risk. For example, the rate of suicide among men with depression and neurotic disorders was 20 times (95% CI = 15, 26) the rate in men with neither disorder. Most disorder combinations were associated with subadditive suicide risk, and there was evidence of competing antagonism in most of these cases.
Subadditivity may be explained by competing antagonism. When both depression and a comorbid psychiatric disorder are present, they may compete to cause the outcome such that having 2 disorders may be no worse than having a single disorder with respect to suicide risk.
先前关于精神障碍相互作用对自杀影响的研究结果不一。我们研究了抑郁症和各种共患精神障碍对自杀的联合影响。
我们进行了一项基于人群的病例-对照研究，纳入了 1995 年 1 月 1 日至 2015 年 12 月 31 日期间在丹麦发生的所有自杀死亡病例（n=14103），以及一个由基线时人群的 5%随机样本组成的对照亚组（n=265183）。我们使用边缘结构模型量化了抑郁症与主要精神障碍（如器质性障碍、物质使用障碍、精神分裂症、双相情感障碍、神经症、饮食障碍、人格障碍、智力障碍、发育障碍和行为障碍）之间的两两组合对自杀的联合影响，并计算了交互作用导致的相对超额风险。我们评估了交互作用导致的负相对超额风险是否存在竞争拮抗作用。
抑郁症和共患精神障碍的所有组合都与自杀风险增加相关。例如，患有抑郁症和神经症的男性自杀率是没有这两种疾病的男性的 20 倍（95%CI=15，26）。大多数障碍组合与自杀风险呈次相加关系，而且在大多数情况下都存在竞争拮抗作用。
次相加作用可能是由竞争拮抗作用引起的。当同时存在抑郁症和共患精神障碍时，它们可能会相互竞争导致结局，因此在自杀风险方面，同时存在 2 种障碍可能并不比存在 1 种障碍更严重。
