Identifying Mood and Anxiety Disorders in Patients With Epilepsy

A familiarity with mood disorders helps neurologists collaborate effectively with mental health professionals.

Neurology Reviews. 2017 July;25(7):9

June 23, 2017|Neurology Reviews

BOSTON—Psychiatric comorbidities are common in patients with epilepsy and crucial for neurologists to recognize. Thus, obtaining a thorough history that includes the patient’s past and family psychiatric history can become an important part of disease management. Psychologic symptoms, particularly those of depression and anxiety, are associated with increased mortality, worse tolerance of antiepileptic drugs (AEDs), worse quality of life, and increased risk of psychiatric iatrogenic adverse events, as outlined in a lecture presented at the 69th Annual Meeting of the American Academy of Neurology. “While it is not necessary for neurologists to be familiar with all the nuances of the different mood disorders, it is important to recognize the different expressions of symptoms of depression and anxiety as you consult and work with a psychiatrist or other mental health professional,” said Andres M. Kanner, MD, Professor of Clinical Neurology and Director of the Comprehensive Epilepsy Center at the University of Miami, Miller School of Medicine.

Past and Current Psychiatric Symptoms

“One in three people with epilepsy will at some point in their lives have [a] psychiatric disorder,” said Dr. Kanner, citing a population-based study of 36,984 subjects that compared people with and without epilepsy in Canada. The data showed that one in four people have experienced suicidal ideation or a suicide attempt, one in five had a major depressive episode, and one in five had an anxiety disorder. Epilepsy is associated with premature mortality, and patients with epilepsy and a mood or anxiety disorder have a 12- to 32-fold higher risk of committing suicide than the general population does.

Psychiatric disorders often precede the onset of epilepsy, Dr. Kanner noted, and a family psychiatric history increases the likelihood of psychiatric disorders in patients with epilepsy. He pointed out that people with epilepsy have a five- to 20-fold higher risk of depression than does the general population, and that patients with depression have a two- to threefold higher risk of epilepsy. Patients with a history of suicidality may have a fivefold higher risk of epilepsy. “Therefore, there is a bidirectional relationship between these conditions.”

Patients who had psychiatric illness before the onset of epilepsy, as well as those with recurring mood and anxiety disorders, have an increased risk that AEDs will cause negative psychiatric symptoms. Phenobarbital, levetiracetam, topiramate, zonisamide, and perampanel are some of the AEDs associated with negative psychotropic properties, said Dr. Kanner. Carbamazepine, oxcarbazepine, valproic acid, lamotrigine, gabapentin, and pregabalin have positive psychotropic properties, which can often yield a therapeutic effect in patients with these conditions.

“Mood and anxiety disorders are more frequently seen in people with temporal and frontal lobe epilepsies, although we now recognize that people with generalized epilepsy are also at increased risk,” Dr. Kanner said. A large percentage of patients with a history of mood and anxiety disorders experience a recurrence of these symptoms within three to six months after temporal lobectomies, he added.

Clinical tools that neurologists can use to identify patients with psychiatric symptoms include the Neurological Disorders Depression Inventory for Epilepsy and Generalized Anxiety Disorder-7 scales.

Timing Is Important

Many physicians recognize when a patient’s depressive or anxiety episode is an interictal phenomenon, meaning that it occurs independently of the seizure. However, they often overlook peri-ictal psychiatric symptoms, Dr. Kanner said. Peri-ictal symptoms include preictal symptoms, which precede the onset of the seizure by two to three days, with the intensity of the symptoms increasing as the seizure gets closer; ictal symptoms, in which the psychiatric symptom is the clinical manifestation of the seizure; and postictal symptoms, which typically follow the seizure within 12 hours to five days.

Interictal psychiatric symptoms respond to pharmacotherapy or cognitive behavioral therapy, Dr. Kanner explained. Ictal phenomena abate with the treatment of the seizure. Preictal and postictal psychiatric symptoms typically do not respond to psychotropic medication.

“People with interictal psychiatric phenomena often have peri-ictal psychiatric symptoms as well,” Dr. Kanner noted. “It is not simply one or the other. It can be one and the other.” He added that iatrogenic psychiatric symptoms that result from psychopharmacologic treatment or surgical treatment are often overlooked.

Quality of Life

“Multiple studies in the last two decades have shown that depression and anxiety are associated with poor quality of life,” said Dr. Kanner. “In fact, in patients with intractable focal epilepsy and comorbid mood and anxiety disorders, the frequency and severity of seizures stop driving the quality of life, and the strongest predictors of poor quality of life end up being the presence of AED toxicity and comorbid mood and anxiety disorders.”