Abstract

Objective

Neuroinflammation is implicated in the pathophysiology of depression. Toxoplasma gondii (T. gondii) causes chronic brain inflammatory process and may thus contribute to both depression and its most serious complication, suicidal behavior. In this study, we hypothesized that latent toxoplasmosis may underlie current depression and/or suicidal behavior.

Method

Currently depressed individuals (N = 384) and age, sex, and residence-matched healthy controls (HC) (N = 400) were tested for latent toxoplasmosis (i.e., positive serum T. gondii IgG antibodies). Exclusions included positive IgM and negative IgG antibodies indicating acute T. gondii infection and history of cognitive problems. Depression severity and history of lifetime suicide attempts were assessed using Beck Depression Inventory (BDI) and Columbia Suicide Severity Rating Scale, respectively.

Results

Participants with seropositive anti-T. gondii IgG antibody had a significantly higher odds of being depressed compared with seronegative participants (OR = 2.9, 95% CI: 1.9–4.3; p < 0.001). BDI score was significantly different between depressed seropositive and depressed seronegative individuals (IgG＋: mean (SD)= 39.65 (11.83) vs. IgG−: mean (SD)= 33.44(9.80); t = 5.03, p < 0.001). Further, seropositive depressed participants were more likely to have prior history of actual suicide attempts compared with seronegative participants (OR= 6.2, 95% CI: 3.4–11.2, p < 0.001).

Conclusions

Latent toxoplasmosis may represent be a risk factor for depression and suicidal behavior. Screening for, and treatment of, underlying T. gondii infection may help improve depression and curb the increasing suicide rates. Future studies should prospectively test these hypotheses to be adequately implemented.

• HIGHLIGHTS

• Latent toxoplasmosis has been linked to history of psychiatric disorders.

• Depressed individuals have higher positivity rate of T. gondii IgG antibody than healthy controls.

• Depressed T. gondii seropositive individuals have increased likelihood to have history of suicidal behavior.

中文翻译：

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潜伏弓形虫病与抑郁和自杀行为有关

摘要

客观的

神经炎症与抑郁症的病理生理学有关。弓形虫( T. gondii ) 会导致慢性脑炎症过程，因此可能导致抑郁症及其最严重的并发症，即自杀行为。在这项研究中，我们假设潜在的弓形虫病可能是当前抑郁和/或自杀行为的基础。

方法

目前抑郁的个体 ( N  = 384) 和年龄、性别和居住地匹配的健康对照 (HC) ( N  = 400) 进行了潜伏弓形虫病检测（即血清弓形虫IgG 抗体阳性）。排除包括阳性 IgM 和阴性 IgG 抗体，表明急性弓形虫感染和认知问题史。抑郁症严重程度和终生自杀未遂史分别使用贝克抑郁量表 (BDI) 和哥伦比亚自杀严重程度评定量表进行评估。

结果

与血清反应阴性的参与者相比，具有血清阳性抗弓形虫IgG 抗体的参与者患抑郁症的几率明显更高（OR = 2.9，95% CI：1.9-4.3；p  < 0.001）。BDI 评分在抑郁血清阳性和抑郁血清阴性个体之间存在显着差异（IgG＋：平均 (SD)= 39.65 (11.83) vs IgG-：平均 (SD)= 33.44(9.80)；t = 5.03，p  < 0.001）。此外，与血清反应阴性的参与者相比，血清反应阳性的抑郁参与者更有可能有实际自杀企图的既往史（OR= 6.2，95% CI：3.4-11.2，p  < 0.001）。

结论

潜伏弓形虫病可能是抑郁症和自杀行为的危险因素。筛查和治疗潜在的弓形虫感染可能有助于改善抑郁症并遏制不断上升的自杀率。未来的研究应该前瞻性地检验这些假设是否得到充分实施。

• 强调

• 潜伏弓形虫病与精神疾病史有关。

• 与健康对照组相比，抑郁个体的弓形虫IgG 抗体阳性率更高。

• 抑郁的弓形虫血清阳性个体有自杀行为史的可能性增加。