Intrusive Thoughts and Obsessive-Compulsive Disorder (OCD)

Intrusive thoughts are insignificant or irrelevant thoughts that occur to a person in any situation. These thoughts usually do not have any meaning but are frightening and scary. A frequent and/or excessively intense occurrence of these thoughts may result in obsessive-compulsive disorder (OCD).

Intrusive Thoughts and Obsessive-Compulsive Disorder (OCD)
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OCD is a neurobiological anxiety disorder. This disorder is associated with the presence of both extraneous thoughts (obsession) and repetitive behavior (compulsion).

  • Obsession: Obsessions are intrusive thoughts, ideas, images, or visuals that pop up in the mind without one’s control. Obsessive thoughts are inappropriate and are capable of making a person feel scared, guilty, anxious, or as if their thoughts are reflecting reality. Individuals who are affected with intrusive OCD often find it disturbing and troublesome, as the thoughts usually involve things that are perceived as important or valuable.
  • Compulsions: Compulsions are the repetitive behaviors of a person that arise as a result of the fear created by intrusive thoughts. The behaviors might be visible, like washing and cleaning, or invisible behaviors, such as counting, praying, and repeating certain words for a long time. People with intrusive OCD thoughts repeatedly perform these behaviors until they are convinced that the danger is over.

The behaviors found in intrusive OCD often include frequent cleaning of a body part, storing unwanted objects, arranging objects in a particular manner, counting some items repeatedly, making several confirmations that the door is locked, checking numerous times that the stove is turned off, and seeking reassurance from a person frequently. These disorders are caused by a variety of conditions that may be genetic, neurobiologic, or environmental, and sometimes a result of medications and/or psychotherapy.

Living With #OCD | Samantha Pena | TEDxYouth@TCS

Types of intrusive OCD thoughts

There are innumerable types of intrusive thoughts that may arise in affected individuals. Some common and frequently occurring thoughts leading to repetitive and compulsive behaviors are related to repetitive checking of one’s actions to avoid contamination, home security systems, avoiding house fires, violent fantasies, avoiding harm to family and loved ones, and arranging things in order to avoid very bad consequences.  

What Are Intrusive Thoughts? & The Connection To OCD, Anxiety & More

Impact of intrusive thoughts on OCD

Dr. Debra Kissen from “the Light on Anxiety Treatment Center” in Chicago, Illinois prepared a checklist of the common intrusive thoughts associated with OCD. To this end, Kissen chose a set of people not having OCD as a sample, and provided them with a series of questions. The questions were related to violence, sex, unwanted actions, and loss of control. The overall sampled population revealed that only a small percentage of them had intrusive thoughts.

However, when the same set of questions was shown to people diagnosed with OCD, about 90% of them reported that they were heavily impacted by intrusive thoughts and experienced a very high level of distress.

OCD is not only dangerous because of intrusive thoughts, but also as a result of one’s responses to those thoughts. When a person tries to fight these intrusive thoughts, the inevitable consequence is that the frequency of the thoughts increases. In other words, the more a person avoids them, the worse it gets.

Causes of intrusive OCD

Studies of OCD show that the condition is sometimes caused by damage to a particular part of the brain known as the basal ganglia. An insufficient supply of oxygen to the brain, neurotoxic agents, and infections caused by bacteria are some reasons for such damage. Repetitive intrusive thoughts can be defined as a state of brain lock that happens to the four parts of the brain. In patients with OCD, these parts are ‘locked together’ due to their overstimulation.

In imaging studies, it has been found that two brain structures that interact with the basal ganglia are more expressive in OCD patients. These structures are known as the anterior cingulate gyrus (ACG) and the orbitofrontal cortex (OFC), both of which act to identify errors in the brain circuit. Their coordination with the basal ganglia sheds light on the genesis of OCD.  

Formally, there are two theories proposed to explain the interaction of basal ganglia and ACG/OFC. According to the first theory, the damage in the ACG or OFC paves the way for a loss of error-detection capabilities, which allows the brain to increase the recurrence of thoughts that lead to OCD. This theory fails to elaborate the reason why people have the feeling of worry and insecurity.

The second theory speculates that the occurrence of OCD is due to the result of pressurization of the ACG/ OFC complex, which ultimately leads to the relay of false error messages to the basal ganglia, producing the feeling of something having gone wrong.


Further Reading

Last Updated: Jul 1, 2023

Dr. Liji Thomas

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.


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