“Will these hands never be clean?” In Shakespeare’s play Macbeth, Lady Macbeth helps plot the brutal murder of King Duncan. She later feels tainted by Duncan’s blood and insists that “all the perfumes of Arabia” cannot sweeten her polluted hands. Disturbed by her compulsion to wash, her doctor is forced to admit: “This disease is beyond my practice.”
In the 400 years since Macbeth was first performed, other doctors, psychiatrists, neuroscientists and clinical psychologists – myself included – have also found the problem beyond the reach of their expertise. We see compulsive washing mostly as a symptom of obsessive-compulsive disorder (OCD), but also in people who have suffered physical or emotional trauma, for example in women who have experienced sexual assault. . The events trigger a deep-seated psychological, and ultimately biological, response.
We know that the driving force of compulsory washing is the fear of contamination by dirt and germs. For example, an obsessive fear of exposure to sexual fluids may induce compulsive washing in OCD and may compel people to limit sexual activity to a specific room in the home. Compulsive washing fails to address the anxiety. Most OCD patients continue to feel contaminated, despite vigorous efforts to clean themselves up. Why does washing fail frequently?
There is currently much debate about which direction psychiatry and research should be headed. We should not underestimate what we can learn from careful observation of patients. Comments like these have prompted my colleagues and I to diagnose a new cause of OCD and other types of compulsive washing: mental contamination.
Lady Macbeth may be an example of someone suffering from this psychological problem. Mental contamination can be created without exposure to a tangible contaminant. It is a feeling of inner filth caused by a psychological or physical violation. The source of pollution is not external contaminants such as blood or dirt, but human contact. The affected person develops an acute sense of contamination that results from direct contact with the violator or indirect contacts such as memories, images, or reminders of the violation.
Typically, these patients are reluctant or unable to even name the violator. Mild forms of this mechanism are prevalent in society – for example, during a bitter divorce. Emotional violations that can lead to mental pollution include degradation, humiliation, painful criticism, and betrayal. Most cases of mental contamination have a moral element. Different psychometric research has confirmed mental contamination as a coherent and measurable concept.
This finding has large and immediate implications for clinical treatment. A common technique for treating compulsive washing – and one that I helped develop – aims to reduce fear, in the hope that it will also reduce the need for washing.
Called exposure and reaction prevention, it asks the patient to repeatedly touch a contaminated object or substance – for example garbage – and not encourage them to wash or clean as they would like. The aim of therapy is to resolve the psychological ‘conditioned’ relationship between the fear and the source of the fear.
Exposure and response prevention is a specialty of cognitive behavioral therapy for OCD and other mental disorders worldwide. Yet it is a sought-after treatment. Up to a quarter of patients give up or refuse it, and up to three out of ten who fail to improve.
Over the past decade, it has become clear that one reason these people do not get help from exposure therapy is that the source of their problematic contamination is not physical but mental. Feelings of mental contamination are pervasive, mainly internal and not accessible. In such a situation, it is wrong to wash hands again and again. And so, crucially, is exposure therapy based on physical contact.
In an initial study of 50 young women who experienced sexual assault, we found abundant evidence of contact contamination and mental contamination. They felt polluted after the attack, and sensibly engaged in vigorous washing. However, a large minority of women continued to feel polluted for several months after the incident.
Mental contamination is essentially a cognitive disorder. The patient’s memories, thoughts and pictures are at the root of the problem. They require a cognitive approach, and my colleagues and I have developed an effective cognitive treatment for mental contamination. We explore the circumstances of the violation and why patients feel they are in danger.
