PARIS – Patients with multiple sclerosis often also manifest major depression or cognitive impairments, but these associated conditions frequently go undiagnosed or untreated, experts said at the annual congress of the European College of Neuropsychopharmacology.
"The data are strong now that depression is common" in patients with multiple sclerosis (MS), with a lifetime prevalence in MS patients of about 50%, said Dr. Anthony Feinstein, professor of psychiatry at the University of Toronto. "There must be something particular about MS that predisposes patients to depression.
Dr. Anthony Feinstein
"You know that [many MS] patients are going to have major behavioral disturbances. The MS rating scales do not take this into account. They are very oriented to motor symptoms, and ignore to a large degree cognitive and behavioral disturbances," he said in an interview. "The behavioral disturbances can be profound."
Cognitive impairment occurs in "up to two-thirds of MS patients, relatively independent of physical disability," said John DeLuca, Ph.D., at the same session. "Cognitive impairment can be seen in early stages [of MS], late stages, or never," said Dr. DeLuca, vice president for research at the Kessler Foundation in West Orange, N.J.
Diagnosing and treating depression in MS patients is important as it can affect quality of life and cognition, and can result in suicidality, said Dr. Feinstein. Suicide among MS patients runs more than sevenfold higher than in the general population, and twice as high compared with patients with other types of neurologic disorders. Study results from other researchers found that MS patients especially at risk for suicide are men, patients younger than 30, and patients during the first 5 years following their initial MS diagnosis.
Dr. Feinstein reviewed findings from a study he and his associates ran on 140 consecutive patients seen at an MS clinic. The analysis showed a 29% lifetime rate of suicide intention, and a 6% rate of suicide attempts in these patients, which compared with a historical 14% intention rate in the general U.S. population and a historical 4% attempt rate reported in Canada. The study done by Dr. Feinstein identified four predictors of suicide intention in MS patients:
• A lifetime diagnosis of major depression.
• More severe major depression with an elevated Hospital Anxiety and Depression Scale score.
• Living alone.
• Alcohol abuse.
These four factors predicted suicidal intent with 70% sensitivity, 95% specificity, and 87% overall predictive ability. One-third of the suicidal patients had received no treatment for their depression, and two-thirds of the patients in this series identified with current major depression were not on antidepressant therapy.
Treatment for major depression in MS patients should generally follow what’s used to treat major depression in patients without MS. Only two randomized, controlled trials of antidepressant treatment have ever been reported for MS patients, and one of these studies occurred about 50 years ago, Dr. Feinstein noted. "In MS patients you need to be aware of susceptibility to side effects, but still tend to the principals from general psychiatry," he said. "The caveat for dosages is to start low and go slow. You need to be careful, especially with polypharmacy and the [potential] effect on cognition and mood."
The disease-modifying drugs commonly used today to treat MS "are safe in patients with depression, and do not make patients suicidal. Should a patient develop depression on one of these drugs, treat the depression, which will improve compliance with the disease-modifying drugs. It is not necessary to stop the disease-modifying drugs," he said. MS patients with severe depression who remain unresponsive to antidepressants are potential candidates for electroconvulsive therapy, especially when the risk for suicide is high. But electroconvulsive therapy poses a risk for weakening the blood-brain barrier and worsening MS symptoms, so he recommended first assessing the stability of the blood-brain barrier using gadolinium-contrast MRI.
MS patients also show a susceptibility to developing other psychiatric disorders, including pseudobulbar affect in up to 10%, bipolar affective disorder, psychosis, and an untreatable form of euphoria caused by a heavy MS-lesion load. Psychosis prevalence in MS patients aged 15-24, when most MS cases first appear, runs 11-fold higher than in the general population, said Dr. Feinstein, who also directs the neuropsychiatry program at Sunnybrook Health Sciences Centre in Toronto.
Results from studies run by Dr. DeLuca showed that cognitive defects in MS result from slowed information processing speed and impaired learning and memory, and that these deficits can significantly impair everyday life activities. These deficits appear even in MS patients without dementia or physical disability. Risk factors for cognitive impairment include early age of onset for patients with pediatric MS or older age in patients with adult-onset MS; male sex; evidence of grey matter atrophy: evidence of low cognitive reserve: and being in the secondary progressive stage of MS.