Let’s start by defining our terms:
‘Obsessions’ are intrusive thoughts/feelings/images that trigger a fear of missing the opportunity to stop a preventable and potentially irreversible catastrophe.
‘Compulsions’ are attempts to escape that fear by eliminating the possibility of allowing that catastrophe to happen. The word ‘compulsion’ comes from the word ‘compel,’ which means to force, or to take away someone’s choice.
‘Rumination’ means thinking about the same thing over and over again. Rumination does not mean repeating the same thought over and over again; it means getting stuck analyzing a topic because you’re trying to figure something out.
People sometimes think that ‘rumination’ is a stream of obsessions because the person is thinking a lot and finds the thoughts distressing. Actually, though, it’s a compulsion, because it’s being done in an attempt to escape the fear by eliminating the possibility of allowing the catastrophe to happen.
As an example, let’s say someone has intrusive thoughts about harming another person. This person sees a knife and feels afraid that they might take it and stab someone. The person then analyzes their thoughts, feelings, and past behavior to try to figure out if they really want to do it, in order to make sure that they don’t do it.
In this example, the person’s initial moment of uncertainty about whether they might stab someone is the obsession. All of the thinking aimed at figuring out if they might really do it, as well as any thinking aimed at figuring out how to stop thinking about it, is a compulsion.
People with OCD often talk about ‘intrusive thoughts.’ When you look more closely, though, most ‘intrusive thoughts’ usually turn out to be compulsive rumination. In fact, I prefer to avoid the term ‘intrusive thoughts’ altogether, because it doesn’t differentiate between the initial, momentary obsession and the compulsive rumination that follows.
Now, you might think that the question of whether rumination is an obsession or a compulsion is just a matter of semantics, but actually it has crucial, practical implications for treatment. In Exposure with Response Prevention (ERP; ExRP), which is the Cognitive-Behavioral Therapy (CBT) for OCD, we expose the person to their obsessions on purpose, while they refrain from doing any compulsions. In other words, if something is an obsession, we elicit it on purpose, but if it’s a compulsion, we eliminate it. Therefore, it matters a lot whether something is an obsession or a compulsion. If rumination were considered an obsession that would mean that the person should do it on purpose! But since rumination is actually a compulsion, that means that the person needs to do everything they can to refrain from doing it.
Now, refraining from rumination might not be easy, but you can’t even work on eliminating it until you identify that as the goal.