Types of mental contamination in OCD

Since it’s been a while since I wrote about OCD, let’s do a quick review of what’s known as mental contamination OCD. A while back I told you about the differences between this type and contact contamination, and today I’m going to take some time to introduce the different forms mental contamination OCD can take. There are four types, and in all of them the main source of contamination is a person:

• Contamination caused by physical violation.
• Self-contamination.
• Visual contamination.
• Morphing.

Contamination caused by physical and psychological violation

It’s normal to feel dirty after a rape or some kind of sexual abuse, but sometimes that feeling persists over the long term and patients describe it as “dirtiness on the inside”. This feeling is characteristic of this type of OCD; it’s hard to describe and to locate physically, but it’s easily triggered by certain memories, thoughts or images. Obviously, it has a strong moral component and doesn’t go away however much the person washes or cleans themselves (at best, these actions bring some relief), which is why it’s described as internal dirtiness.

As you read this, you might be thinking of post-traumatic stress disorder (PTSD). It’s true that there’s some overlap between this type of OCD and PTSD, but one of the key differences is that mental contamination OCD can also arise after an emotional or psychological violation, that is, without any physical contact at all. This type of violation would include, for example, betrayal or humiliation. In these cases we’d speak of contamination caused by psychological violation, which shows up in practically the same way as contamination triggered by a physical violation.

Self-contamination

The source of contamination is the person themselves. In most cases it’s triggered by unpleasant thoughts or images, or by certain actions the person considers unacceptable, which set off feelings of guilt and shame. The intrusive thoughts and images that lead to the contamination obsession tend to be sexual, religious and/or aggressive in nature, so there’s a strong moral component.

Because the person is the source of contamination, the feeling of contamination and recontamination is constant, so it interferes considerably with the daily life of whoever experiences it.

Visual contamination

This happens when a person feels contaminated just by seeing someone they consider strange, immoral or disreputable. It’s as if the person somehow picked up these undesirable traits simply by seeing someone who supposedly has them. Sometimes, seeing someone behave strangely in public makes the person afraid that, just by having witnessed it, they’ll be contaminated and lose their mind.

Morphing

This is similar to the previous type, but with some nuances. It involves the belief that, whether through visual contamination or physical contact, you can absorb or catch another person’s negative traits. The supposed source of contamination is usually people seen as marginal: mentally unstable individuals, drug users, people of questionable morals… Interestingly, people of high socioeconomic status aren’t usually seen as sources of contamination in cases of morphing. Many people with this type of OCD have previously had contact contamination OCD.

A fear that often lies behind many cases of morphing is the idea that there are germs that can pass mental illness from one person to another.

In mental contamination OCD there are often a lot of underlying magical-thinking ideas, and it’s essential to work on them at a cognitive level. We’ll come back to this topic later on, but you can find all this information and much more in The Oxford Guide to the Treatment of Mental Contamination by Rachman, Coughtrey, Shafran and Radomsky.