Interictal Dysphoric Disorder Fast Facts

Interictal dysphoric disorder (IDD) is a mental condition associated with epilepsy.

About a quarter of people with epilepsy experience symptoms consistent with IDD.

Common IDD symptoms include depression, anxiety, and irritability.

There is still discussion in the medical community over whether IDD is a distinct condition that only affects people with epilepsy.

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Common IDD symptoms include depression, anxiety, and irritability.

What is Interictal Dysphoric Disorder?

Interictal dysphoric disorder (IDD) is a condition in which a person with epilepsy experiences issues with mood, behavior, and other aspects of mental health. The disorder’s name refers to the fact that sufferers experience psychiatric symptoms in the period between epileptic seizures.

Symptoms of Interictal Dysphoric Disorder

Common symptoms of IDD include:

  • Depression
  • Lack of energy
  • Pain
  • Sleeplessness
  • Anxiety
  • Panic attacks
  • Irritability
  • Mood swings
  • Sudden outbursts of anger or rage

What Causes Interictal Dysphoric Disorder?

The cause of IDD is unknown. People with epilepsy suffer from mental symptoms such as depression at a rate several times that of the general population. However, it is unclear whether epilepsy is the cause of IDD or whether the symptoms of IDD are a precursor to the onset of epilepsy. It is not uncommon, for example, for people to experience mood disorders such as depression before they are diagnosed with epilepsy.

Is Interictal Dysphoric Disorder Hereditary?

IDD does not appear to be an inherited disorder. However, epilepsy itself sometimes has a genetic component, so inherited factors can increase a person’s risk of developing IDD.

Genetic factors influence whether someone will develop epilepsy. The disorder doesn’t result from a single gene. It can happen to anyone, at any age. If a close relative, such as a parent or sibling, has epilepsy, an individual may be at higher risk for epilepsy than someone with no family history. However, the chance of passing epilepsy down through generations is low.

If a parent has epilepsy, there is a 9%–12% chance that the child will also have epilepsy. Although most siblings of a child with epilepsy do not develop the disorder, brothers and sisters have a higher risk of epilepsy. In addition, if one twin has idiopathic epilepsy, meaning it arises for no identifiable reason, the identical twin is also likely to develop the disorder.

How Is Interictal Dysphoric Disorder Detected?

One of the main challenges in diagnosing IDD is differentiating its symptoms from other mental disorders such as major depressive disorder (MDD). IDD and major depression share many of the same symptoms, and people with epilepsy are at increased risk for developing major depression. However, the depressive symptoms of IDD differ from those of major depression in crucial ways:

  • Periods of depression and low mood in IDD are intermittent and may last for hours or days.
  • Low mood in MDD is persistent for periods of two weeks or longer.
  • Depressive episodes in IDD tend to be less severe than those of MDD.

How Is Interictal Dysphoric Disorder Diagnosed?

A doctor may suspect IDD when a patient with epilepsy exhibits a distinctive cluster of psychiatric symptoms. The symptoms of IDD are divided into three categories:

Depressive Symptoms

  • Low mood
  • Lack of energy
  • Pain
  • Insomnia

Affective Symptoms

  • Panic-like episodes
  • Anxiety

IDD Specific Symptoms

  • Unstable irritability or anger
  • Unstable euphoric moods

All of these symptoms are characterized by their intermittent, unstable nature.

How Is Interictal Dysphoric Disorder Treated?

Treatment of IDD typically involves using medication to treat both the underlying seizures and the psychiatric symptoms of the disorder. Anticonvulsant drugs effectively control seizures in many cases, and serotonin reuptake inhibitors (SSRIs) such as sertraline and citalopram have proven safe and effective in treating IDD symptoms.

In some cases, psychotherapy may also be recommended for IDD treatment.

How Does Interictal Dysphoric Disorder Progress?

Left untreated, IDD can progress to more severe depression and anxiety disorders. People with epilepsy who also suffer from depression are at increased risk for many long-term problems, including:

  • Increased seizure severity
  • Development of drug-resistant seizures
  • Poor recovery from seizures
  • Injuries associated with seizures

How Is Interictal Dysphoric Disorder Prevented?

In most cases, IDD can’t be prevented, but the management of seizures and treatment of any co-existing mental health symptoms may help control the severity of IDD.

Interictal Dysphoric Disorder Caregiver Tips

The most important thing you can do for a loved one with epilepsy is to be supportive. Epilepsy is a common condition. Some seizures rarely cause problems.

Overall, the chance of injury is higher for people with uncontrolled seizures. Bruises, cuts, burns, and falls are all common injuries. Less common concerns include breathing problems, drowning (due to a seizure while swimming or bathing), car accidents (many states restrict driver’s licenses for those with epilepsy), and pregnancy complications.

Caregivers should also be aware of the rare, but life-threatening complications of epilepsy, including:

  • Status epilepticus, a state of continuous seizure activity lasting more than five minutes. People with status epilepticus have an increased risk of permanent brain damage and death.
  • Sudden unexpected death in epilepsy (SUDEP). People with epilepsy also have a small risk of sudden unexpected death. However, the risk is very low (about 1% of people with epilepsy), and the cause is unknown. People whose seizures aren’t controlled by medications or experience frequent tonic-clonic seizures have a higher risk of SUDEP.

Many people with epilepsy and IDD also suffer from other brain and mental health-related issues, a condition called co-morbidity. Here are a few of the disorders commonly associated with epilepsy:

Interictal Dysphoric Disorder Brain Science

IDD has been a controversial subject since its description in the middle of the twentieth century. The disagreement has not been over whether people with epilepsy are more at risk of the psychiatric symptoms associated with IDD. Numerous studies have shown that to be true. Instead, the discussion has considered whether IDD is a condition distinct from other mental disorders and whether it exclusively affects people with epilepsy.

Most scientists now believe that IDD represents a collection of symptoms not specific to epilepsy. Similar symptoms occur in people without epilepsy and those suffering from other neurological disorders such as Parkinson’s disease.

Interictal Dysphoric Disorder Research

Title: Low-Frequency TMS for Depression in Epilepsy (LFTMS)

Stage: Recruiting 

Principal Investigator: Krzysztof A. Bujarski, MD   

Dartmouth Hitchcock Medical Center

Lebanon, NH

The purpose of this study is to determine if low-frequency transcranial magnetic stimulation (TMS) is safe and feasible for treating depressive symptoms in patients with epilepsy. Patients will receive an accelerated protocol of TMS consisting of three consecutive days of treatment. In addition, patients will have in-person follow-up visits after one month and again after six months.

This pilot study is designed primarily to assess whether patients with epilepsy can safely tolerate low-frequency transcranial magnetic stimulation in an accelerated protocol to treat depression. The investigators aim to treat 12 patients with epilepsy and co-morbid depression to receive a total of 15 hours of transcranial magnetic stimulation over three days at Dartmouth-Hitchcock Medical Center (DHMC). The investigators will assess the safety of this protocol with regards to seizure frequency and other side effects of TMS treatment and the feasibility of using an accelerated protocol in this patient population. In addition to these primary aims, our secondary goal is to determine if dense array EEG can provide a useful biomarker for depression and its treatment in focal epilepsy. A structural and functional MRI will be obtained before treatment and a dense array EEG before and after TMS treatment to assess for changes in specific dense array EEG-based biomarkers.

In addition to recruiting patients, the study staff will likewise request that family members or friends of the patient accompany the patient and monitor them for increased seizure frequency. The recruited family member will bring the patient to the treatment and stay with the patient overnight at a local hotel and monitor for possible seizures or other adverse events of treatment. Family members will be instructed in seizure safety and be given emergency phone numbers to call if the patient is experiencing adverse effects of TMS.


Title: Incorporating Multidimensional Psychosocial Interventions Improves the Well-being of Individuals With Epilepsy

Stage: Recruiting 

Principal Investigator: Ramon Edmundo D. Bautista, MD

University of Florida

Jacksonville, FL

This study aims to incorporate multidimensional self-management programs into the routine care of epilepsy patients. Consenting patients will enroll in one of four interventions that help improve medication adherence, increase seizure awareness and documentation, improve memory and deal with stress and depression.

Though tremendous advances have been made in the diagnosis and treatment of individuals with epilepsy, much remains to be done when it comes to improving their psychosocial well-being. Many individuals with epilepsy have difficulty adhering to treatment, documenting their seizure types, coping with memory difficulties, dealing with stress, and suffering from depression. These factors limit the quality of life of epilepsy patients and prevent them from realizing their full potential.

Patients will enroll in one of four interventions that help improve medication adherence, increase seizure awareness and documentation, improve memory and deal with stress and depression. In addition, patient assessments will be conducted before and after the intervention to gauge the efficacy of the programs.

The specific aims of this study are to assess the feasibility and patient acceptability of incorporating multidimensional self-management and psychosocial interventions into routine epileptic care and determine whether these incorporations improve self-management, quality of life, and other measures of well-being.


Title: A Computerized CBTi for Insomnia in Epilepsy

Stage: Recruiting 

Principal Investigator: Nancy Foldvary-Schaefer, DO

The Cleveland Clinic

Cleveland, OH

A growing interest in the relationship between epilepsy and sleep has resulted in several investigations demonstrating the high prevalence of sleep disturbances and disorders in people with epilepsy (PWE). PWE frequently report daytime sleepiness, insomnia, and other sleep problems.

Insomnia is among the most common sleep complaint in PWE. The prevalence of moderate-to-severe insomnia using the ISI ranges from 15% to 51%. A recent case-control study found an association between insomnia symptom severity and poorer seizure control. Difficulty maintaining sleep is the most common insomnia presentation, followed by difficulty initiating sleep. Both patterns are accompanied by a decrease in total sleep time and an increase in the number of awakenings, arousals, and wake time after sleep onset, leading to a state of relative sleep deprivation. Like epilepsy, insomnia disorders are commonly associated with co-morbid depression in the general population, confirmed in a cohort of adults with epilepsy from The Cleveland Clinic’s epilepsy center. In turn, treatment of depression has been shown to improve insomnia in the general population. Further, improved seizure control has been observed following treatment of other co-morbid sleep disorders such as obstructive sleep apnea and poor sleep hygiene. Innovative sleep treatments for PWE are needed.

To date, there are no studies exploring sleep and seizure outcomes with the treatment of insomnia in PWE. Cognitive Behavioral Therapy for Insomnia(CBT-i) is generally the preferred initial treatment for most cases of primary insomnia. CBT-i examines and promotes modifications in thoughts and behaviors that perpetuate insomnia. The validity of CBT-i has been well established, and the American College of Physicians has acknowledged CBT-i as the first-line therapy for insomnia with treatment effects that outlast those of sedative-hypnotic medications. Despite its established efficacy, CBT-i is not widely accessible due to the lack of trained clinicians, stigmatization in receiving psychological services, geographical remoteness to trained providers, and cost. Treatment typically involves a series of up to 10 visits at weekly or biweekly intervals.

In recent years, CCBT-i programs have been developed that offer web-based treatment. One such program is GoTo sleep (GTS), developed and validated by investigators at the Cleveland Clinic. GTS constitutes six weeks of therapy based on the principles and methods of CBT-i presented as a series of daily lessons, learnable skills, and personalized recommendations supported by graphics, animations, audio, and video. The program includes the basic elements of CBT-i, including sleep hygiene, sleep restriction, stimulus control, cognitive restructuring, and relaxation training. The efficacy of CCBT-i has been demonstrated in several randomized controlled trials involving patients with primary insomnia, including one using GTS, where the program was found to be superior to usual care (sleep hygiene instruction) after six weeks of therapy. Further, we recently conducted a pilot study comparing GTS and standard sleep hygiene instruction in Parkinson’s disease patients with insomnia and found a greater reduction in ISI scores with CCBT-i (-7.9 vs. -3.5; p=0.03).

Given the prevalence of insomnia in epilepsy and the known association between seizure occurrence and sleep impairment, the investigators hypothesize that treating insomnia with CCBT-i will improve insomnia symptoms and seizure control in PWE.

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