Contamination concerns are among the most common symptoms of obsessive-compulsive disorder (OCD). Research has recently focused on mental contamination, defined as feelings of dirtiness and/or washing behaviour arising in the absence of direct contact with a contaminant. Mental contamination is highly prevalent; a substantial amount of washing behaviour related to contact contamination may actually be a manifestation of mental contamination. As such, washing may reflect an attempt to cleanse oneself of a feared corrupted self, rather than of any physical contaminant. Indeed, a recent treatment study found that reductions in feared self-perceptions also predicted reductions in contamination symptomatology; we propose that this link may be explained by mental contamination. We examined whether mental contamination, relative to established OCD belief domains, mediated the relationship between feared self-perceptions and contact contamination. In our sample of 626 undergraduate participants, feared self-perceptions significantly predicted contact contamination symptoms, with mental contamination and two OCD belief domains (perfectionism/intolerance of uncertainty, importance of/control over thoughts) as significant mediators. Importantly, mental contamination was the strongest mediator. These findings provide further evidence for the predictive power of vulnerable self-themes in OCD and highlight the important role of mental contamination in this relationship with regard to contamination symptoms.

污染问题是强迫症（OCD）最常见的症状之一。最近的研究集中在心理污染，定义为在没有直接接触污染物的情况下产生的脏污和/或洗涤行为的感觉。精神污染非常普遍；与接触污染有关的大量洗涤行为实际上可能是精神污染的一种表现。因此，洗涤可能反映了一种企图从恐惧的堕落自我中清除自己，而不是清除任何物理污染物的尝试。确实，最近的一项治疗研究发现，恐惧的自我感觉的降低也预示着污染症状的降低。我们建议这种联系可以用精神污染来解释。我们检查了相对于已建立的强迫症信念域而言，精神污染是否介导了恐惧的自我感知与接触污染之间的关系。在我们对626名本科生的抽样调查中，担心的自我感知显着预测了接触污染症状，其中心理污染和两个OCD信念域（完美主义/不确定性的不容忍，思想的重要性/控制力）是重要的调解人。重要的是，精神污染是最强的调解人。这些发现为OCD中易受伤害的自我主题的预测能力提供了进一步的证据，并突出了精神污染在这种与污染症状有关的关系中的重要作用。精神污染是最强的调解人。这些发现为OCD中易受伤害的自我主题的预测能力提供了进一步的证据，并突出了精神污染在这种与污染症状有关的关系中的重要作用。精神污染是最强的调解人。这些发现为OCD中易受伤害的自我主题的预测能力提供了进一步的证据，并突出了精神污染在这种与污染症状有关的关系中的重要作用。