OCD and the anxiety system

The anxiety system in thoughts, feelings, the body and actions

The anxiety system is part of our survival and defence system. It helps us detect danger, react quickly and remember what has been dangerous in the past. This is a major advantage when the danger is real. But the system can also sound the alarm in response to something that is not dangerous. From a cognitive behavioural perspective, the anxiety response can be described in terms of four areas that influence one another:

• A cognitive part that registers and remembers past dangers or imagines what might become dangerous. It can also plan how danger might be avoided or prevented. A person may remember getting an upset stomach after eating at a rather unhygienic restaurant abroad. Their thoughts may then tell them that following standard food-hygiene guidance is not enough.

• An emotional part that may be experienced as anxiety, unease, disgust, guilt or a sense that something is not quite right. For example, many people with a fear of bacteria feel intense discomfort when touching things they believe are dirty.

• A physiological part that prepares the body to respond. The heart may beat faster, the person may sweat and the body may tense when they encounter something they experience as dangerous or intensely unpleasant.

• A behavioural part that can include visible actions, avoidance and mental rituals. For example, a person with an unwanted thought that they might be a paedophile may repeat a short phrase in their mind to reassure themselves that the thought is not true.

The anxiety system is a “drama queen”

Humans have a highly effective anxiety system, which is one reason we have been so successful at surviving. In most situations, it is also useful. We need to know that poisonous mushrooms are dangerous to eat, that we should only cross the road when the light is green because being hit by a car can be fatal, and that we should wash our hands after touching raw meat. But sometimes the anxiety system exaggerates. It quickly learns what might be dangerous, but it does not always assess calmly how likely the danger is.

One example would be hearing about a patient who injured their knee, came into contact with a flesh-eating bacterium while in hospital and ultimately lost their leg as a result. The anxiety system may then become overactive and direct all its attention towards wounds, bacteria, cleanliness, hospitals, doctors and irregularities in the skin. All four areas of the anxiety system become activated: we can think only about whether we hurt ourselves when we bumped into someone in the street; our heart begins to race whenever we notice even a slightly red patch of skin; we feel intense anxiety that the red patch might in fact be a flesh-eating bacterium; and as a result, we continually inspect our skin for scratches, read about flesh-eating bacteria online, bathe constantly, scrub our skin and perhaps call the doctor whenever we get a graze.

We do all this even though we have not actually been infected with a flesh-eating bacterium. Once the alarm has subsided a little, we may well be able to see that the event we heard about was so rare that our reaction is excessive. But in the moment, the anxiety system shouts much louder than reason. The reaction becomes intuitive—more like a gut feeling—and acting against a gut feeling is extremely difficult even when part of us can see that the reaction is out of proportion. It is like a small “drama queen” demanding attention and needing help to settle down.

The anxiety system is not fussy

The anxiety system often plays a central role in OCD, but OCD does not always feel primarily like anxiety. For some people, disgust, guilt, a sense of inner incompleteness or a feeling that something is not quite right may be more prominent. What these experiences have in common is that something feels so important, dangerous or wrong that the person has a powerful urge to do something about it.

Thoughts used to counter the obsession, analysis, visible compulsions, mental rituals and avoidance can all bring short-term relief. That relief can teach the system that the strategy was necessary, making it more readily available the next time. In therapy, the person works on allowing doubt and discomfort to remain without using the same strategies. In this way, OCD can gradually take up less space.

Why, then, are there so many different types of OCD? The anxiety system is not systematic in what captures its attention. For some people it is bacteria, for others order, and for others still thoughts about paedophilia. Obsessions often become more powerful when they touch on something of great personal importance or conflict with the person they want to be. This does not mean that the content of the thought reveals who the person is. On the contrary, the thoughts are unwanted and can create profound doubt about what the thoughts might say about who they are.

Values and personal rules for living can both matter, but they are not the same. Values concern what a person wants to stand for, while rules for living are inner rules about how they feel they must be or act. In short, the anxiety system is not fussy about what captures its attention. Nor is the subject of the thought alone what keeps OCD going. What matters is the meaning given to the thought and the repeated attempts to obtain certainty, control or short-term relief.

Summary

The anxiety system plays an important role in OCD, but the response may also be marked by disgust, guilt or a powerful sense that something is not quite right. The content of obsessions can vary greatly, while attempts to obtain certainty, control or short-term relief recur. Thoughts and actions intended to counter the obsession can briefly reduce discomfort, but also make the same strategies more likely to be used again next time. Through cognitive behavioural therapy, a person can learn other ways of responding to doubt and discomfort, allowing OCD gradually to loosen its grip.