Inference based therapy

inference based therapy
Dr Elaine Ryan
Written by Dr Elaine Ryan Psychologist and Founder of MoodSmith® Elaine obtained her Dr in Psychology from the University of Surrey and has worked in psychology for 20 years. Dr Ryan specialises in Intrusive Thoughts, OCD and anxiety-related conditions.

Inference based therapy might not be as well known as other models that help with obsessions. Still, I have included it in this introductory series to intrusive thoughts for its value in helping you with obsessions.

According to the model, intrusive thoughts (obsessions) do not intrude or pop uninvited into your mind.


The initial thought, for example, what if I did something terrible in the past and didn’t remember it, only becomes a problem and eventually something that the person obsesses about through a series of doubt and faulty reasoning.


According to the theory, Doubt is the origin of the obsession and is the focus of inference-based therapy.

The doubt becomes exaggerated by a series of narratives and faulty reasoning

Mark is a 24-year-old man who attended therapy for obsessional thoughts regarding his sexual orientation. Mark is heterosexual but is troubled by thoughts that his sexual preference is changing.

His reason for attending therapy was the thoughts in his head and how his behaviour had changed. Mark regularly checks to ensure his sexual identity has not changed by testing if women still attract him and if men attract him. His current concerns have affected his relationship with his partner for two years.

HOCD or sexual orientation OCD is a sub-type of the mental health condition obsessive-compulsive disorder. A person of any sexual orientation can experience this condition. Having HOCD leaves the person distressed by confusing obsessions that can affect all aspects of their life. People with this subtype of OCD do not mean that they think negatively of people with different sexual identities; they are suffering from a form of OCD.

The focus of Inference Based Therapy is not on the intrusive thought but the doubt and the series of narratives or stories told by the self that created the obsession.

The first step in therapy is to uncover Mark’s doubt.
What if I am gay?

This doubt, according to IBT, is called the first Inference. An inference is an opinion you form based on the information you have.

What would happen if this doubt were genuine? Mark stated that he would have to leave his current partner. This is called the feared consequence.


When a person experiences doubt, they have used information and knowledge they already have to arrive at a conclusion.

What information and knowledge did Mark have to arrive at his doubt? What if I am gay?

He stated it started when he walked past a man on the street and thought he was dressed well and looked good. Later that day, he watched a program on TV on same-sex couples and remembered the man on the street and wondered did it mean something about him.

Someone called him gay when he was in school.

Maybe these things meant I was gay and didn’t know it.
Maybe the incident in school meant I was gay.

An essential aspect of Inference based therapy is the weight given to ‘maybes’ and the difference between real and imaginary doubt.


Real information was that he was in a heterosexual relationship, and imaginary doubt arose from wondering why he found a man attractive. It came from his internal thought processes instead of the external reality of never being attracted to or wanting to have a romantic relationship with the same sex.

Using this information and arriving at the doubt, what if I am gay, is called inferential confusion, in that a conclusion was made based on a flawed reasoning process.

When Mark’s doubting narrative becomes strong, it is natural that he will worry and try to prevent feared consequences that arise from the doubt, i.e. he would have to leave his partner. This leads to compulsions such as checking and testing his sexual identity.

It is crucial to note that the doubt is not a fact, but it takes on a life of its own, through doubting stories or narratives that Mark creates. He looks for experiences throughout his life to suggest that his doubt might be true.

Mark’s current problem is not the original thought of thinking that a man was dressed well in the street, but the doubt created leading to the obsession, what if I am gay and the feared consequence that he would have to leave his partner.

Hopefully, you can see the intrusive thought, what if I am gay, according to Inference based therapy, started from faulty reasoning that originated from that first instance of seeing a man on the street and the inaccurate appraisal that led to doubt and eventually the obsession, what if I am gay?

In CBT, he would look for evidence for and against this thought and modify his behaviours, such as checking his attraction levels to both sexes.

If he used exposure response prevention, he would learn to manage his thought of what if I am gay without engaging in any compulsive behaviours, which would be the checking.

In inference-based therapy, rather than focusing on the obsession, what if I am gay, he would work with the doubt and faulty appraisals that led to it.

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