The Link Between OCD and Epilepsy

Although it may be surprising to some, there is a longstanding association between epilepsy and various forms of mental illness. Indeed, among patients with temporal lobe epilepsy, a form of epilepsy in which seizures begin in the temporal lobe of the brain, some estimates are that 70% meet diagnostic criteria for at least one form of mental illness and the most common are mood and anxiety disorders.

Although numbers vary from study to study, research suggests that between 10% and about 20% of people with temporal lobe epilepsy have ​obsessive-compulsive disorder (OCD). This rate is much higher than would be expected in the general population, where the prevalence is over two percent.

What Is Epilepsy?

Before discussing the relationship between OCD and epilepsy, it may be helpful to first define what epilepsy is.

Epilepsy affects up to one percent of the population. Although there are many types of epilepsy, each involves a disruption in the communication between neurons in the brain. When normal communication between nerve cells is disrupted it can lead to a pattern of neuronal activity that is known as a seizure.

Seizures can take on many forms and can range from subtle alterations in consciousness to full-blown, so-called "grand mal" seizures. In this form of seizure, consciousness is lost and the entire body goes into violent convulsions. These are the type of seizures the general public is most familiar with.

People with epilepsy usually experience numerous seizures and very often require treatment with medication to control seizure activity. In rare cases, brain surgery to remove certain regions of the brain may be necessary to control the seizures and regain quality of life.

Similar Behaviors of OCD and Epilepsy

Interestingly, it has been observed that people with temporal lobe epilepsy often display a specific pattern of behavior referred to as interictal behavior syndrome.

This behavioral syndrome looks a lot like OCD in that it is often characterized by alterations in sexual behavior, increased religiosity and extensive, and in some cases compulsive, writing and drawing (sometimes called hypergraphy).

These behaviors alone are not nearly sufficient for a diagnosis of OCD; however, they are the first clue that there is a vulnerability to engaging in obsessive, repetitive behaviors among individuals with temporal lobe epilepsy.

In temporal lobe epilepsy, OCD usually occurs early after the onset of seizures. Later onset of OCD symptoms in epilepsy may be tied to brain damage occurring in brain "circuits" exposed to repeated seizure activity.

It has been suggested that epilepsy may disturb circuits connecting different brain regions, particularly within the limbic system, basal ganglia and frontal cortex, brain regions that have been strongly implicated in the expression of OCD symptoms.

Although not consistent across all studies, disruptions in the neurochemical serotonin have also been noted in both epilepsy and OCD. While some patients have been reported to have worsening OCD after surgery to remove brain areas affected by epilepsy, other patients have been noted to have improvement.

Treatment of OCD in the Context of Epilepsy

Treatment of OCD in the context of epilepsy is very similar to OCD which occurs alone. Psychological treatments such as exposure and response prevention therapy or cognitive-behavioral therapy are a good first choice; however, because of the cognitive changes sometimes experienced in epilepsy, treatment may need to be adjusted accordingly.

Treatment with medication is also possible; however, because some of the medications used to treat OCD can lower seizure threshold, these need to be used with caution.

In addition, potentially negative interactions between OCD medications and antiepileptic drugs need to be monitored. If you are seeking medical treatment for OCD, advise your family doctor or psychiatrist of all underlying medical conditions.

Studies suggest that OCD in the context of epilepsy is often grossly under-diagnosed. This is important because when OCD and epilepsy co-occur, the risk of depression rises substantially. Depression makes the treatment of OCD and epilepsy more difficult, reduces treatment adherence, and increases the risk of suicide.