Conference Coverage

Mental illness in MS: ‘Follow the why’



Multiple sclerosis (MS) adds a layer of complexity to psychiatric illnesses such as depression, and the usual rules of treatment do not necessarily apply, a neuropsychiatrist cautioned colleagues who treat MS.

Dr. Laura T. Safar, a psychiatrist affiliated with Beth Israel Deaconess Medical Center, Boston Randy Dotinga/MDedge News

Dr. Laura T. Safar

For example, depression may strike a patient as a primary condition, just as it could in anyone. But it may also be a manifestation of MS itself, or a side effect of an MS medication, or spurred by the fatigue and pain caused by MS, said Laura T. Safar, MD, a psychiatrist affiliated with Brigham and Women's Hospital, Boston*. As a result, popular psychiatric treatments such as SSRIs might not necessarily be the best approach, said Dr. Safar, who spoke in an interview and during a presentation at the annual meeting of the Consortium of Multiple Sclerosis Centers.

“You need to follow the why,” she said in the interview, adding that it is crucial to view neurologic and mental health as one and the same in MS. “More integration,” she said, “continues to be the way to go.”

Here are some pearls and tips from Dr. Safar’s presentation on treating psychiatric conditions in patients with MS:

Mental illness incidence

Depression is estimated to affect 25%-45% of people with MS over their lifetimes, while bipolar disorder is thought to affect 6% of patients and a quarter are estimated to have anxiety.

Researchers also believe as many as 10% of patients are affected by pathological laughing and crying during their lives.

Psychiatric side effects

Interferon drugs are notoriously linked to depression and psychosis. Glatiramer acetate (Copaxone) and natalizumab (Tysabri) are also thought to cause psychiatric side effects in some cases – anxiety and depression, respectively. But drug-modifying therapies can also provide relief on the psychiatric front, Dr. Safar said.

Meanwhile, dozens of other drugs used to treat aspects of MS such as spasticity, pain, and fatigue have possible psychiatric side effects.

Alternatives to SSRIs

SSRIs are often a first option in psychiatric patients, but those with MS may need another option because so many – an estimated 80% – also have fatigue, Dr. Safar said.

Alternatives for patients with MS include serotonin and norepinephrine reuptake inhibitors (SNRIs), which may have an advantage over SSRIs, she said. Specifically, SNRIs and bupropion (Wellbutrin) may be better for patients with fatigue and cognitive problems, she said, while vortioxetine (Trintellix) may benefit cognition.

Treating anxiety

There are no data regarding the best drug treatment for anxiety in patients with MS, she said, and SSRIs are typically the starting point. Consider SNRIs and duloxetine, respectively, when patients also have significant fatigue and cognitive symptoms. Use benzodiazepines only in occasional cases (such as anxiety regarding an MRI) and severe cases, she said.

MS-specific side effects

Beware of MS-specific side effects, Dr. Safar said. Some common psychiatric drugs, especially citalopram (Celexa) and escitalopram (Lexapro), may increase the QTc interval and shouldn’t be used in combination with the MS drug fingolimod (Gilenya).

And, she said, bupropion is “a very helpful agent” but poses a rare risk of seizures. Dr. Safar said she has seen this side effect a couple times over 10 years, but both were in patients with “other factors involved.” Still, “it’s something to keep in mind.”

Also understand that serotonergic agents can worsen restless legs syndrome, which is more common in patients with MS. Dr. Safar advises monitoring for the condition.

Pathological laughing, crying

Episodes of so-called pathological laughing, crying, or both tend to be brief, frequent, and intense. They may be sparked by nothing at all, and more often feature crying.

Certain SSRIs have proved helpful for the condition in MS, Dr. Safar said. Research also supports a combination of dextromethorphan (cough suppressant) and quinidine (a drug used to treat arrhythmias and malaria). The combination is sold together as Nuedexta.

Other agents such as venlafaxine (Effexor) and duloxetine (Cymbalta) have very limited data and shouldn’t be first-line treatment, she said.

Dr. Safar reports no relevant disclosures.

Correction, 5/31/19: An earlier version of this article misstated Dr. Safar's hospital affiliation.

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