BOSTON—Patients with multiple sclerosis (MS) have an increased risk of schizophrenia and bipolar disorder, researchers reported. In addition, the results of a retrospective analysis suggest that these disorders have shared etiologies.

“To our knowledge, this is the first large-scale study to test this association,” said Sreeram Ramagopalan, PhD, a research fellow at Evidera in London. “Caregivers should appropriately diagnose and manage these conditions in patients with MS.”

Recent studies have found similar risk factors for patients with schizophrenia, bipolar disorder, and MS, including immunogenetic associations, vitamin D deficiency, and infections. Dr. Ramagopalan and colleagues sought to test whether MS patients are at an increased risk of schizophrenia and bipolar disorder using the Hospital Episode Statistics database of hospital admissions in England.

The investigators analyzed a database of linked statistical records of hospital admissions and death certificates for all of England. The analysis included the years from 1999 to 2011 and examined data for 52 million people. The researchers determined rate ratios for psychiatric disease, comparing rates of schizophrenia and bipolar disorder in a cohort of all people in England admitted with MS (n = 82,176) with rates in a comparison cohort of patients admitted for various other, mainly minor, medical and surgical conditions (n = 9,818,240). Rates were based on person-days and were standardized by age (in five-year age groups), sex, calendar year of first recorded admission, region of residence, and quintile of patients’ Index of Multiple Deprivation score (as a measure of socioeconomic status), using the indirect method of standardization.

Patients with MS had significantly elevated risks for schizophrenia (rate ratio [RR] = 1.42); schizophrenia, schizotypal, and delusional disorders (RR = 2.08); and bipolar disorder (RR = 1.73). The researchers found these associations in males and females. The associations also were evident when the investigators identified a first schizophrenia or bipolar diagnosis at least a year after the first MS admission. The latter result suggests that the association is not a reflection of surveillance bias.

—Erik Greb

Does Overactive Bladder Correlate With MS Relapses or Progression?
Overactive bladder (OAB) with leakage is associated with a higher number of relapses and increased disease progression among patients with multiple sclerosis (MS), according to researchers.

Patients with OAB and leakage “should be closely monitored for indications of overall worsening function,” said Stacey S. Cofield, PhD, Associate Professor of Biostatistics at the University of Alabama at Birmingham, and colleagues.

Dr. Cofield and colleagues investigated the relationship between self-reported bladder dysfunction and relapses and severity of disability during five years of follow-up. The researchers examined data from the North American Research Committee on MS (NARCOMS) database, a voluntary registry for people with MS that involves an enrollment survey and semiannual updates. They included participants who responded to questions about bladder function in fall 2005. Eligible participants were US residents with no surgical alterations to the bladder who completed one or more update survey annually from 2005 through 2010.

The investigators classified respondents in 2005 as having wet OAB (ie, urgency with urgency-related leakage), dry OAB (ie, urgency without urgency-related leakage), or no OAB. They defined progression as a one-point increase in Patient-Determined Disease Steps (PDDS) from 2005 to 2010 and at 2010.

A total of 4,870 respondents were included in the analysis. Approximately 74% of respondents were female. About 94% of participants were Caucasian, and the population’s mean age was approximately 51. Respondents’ mean disease duration in 2005 was 12 years.

Of all respondents, 60.2% were classified as having wet OAB, 15.2% were classified as having dry OAB, and 24.6% were classified as having no OAB. Among participants with wet OAB, 50.8% reported slight incontinence, 30.6% reported moderate incontinence, and 18.7% reported great incontinence. In 2005, patients with wet OAB were older and had a longer disease duration than the other respondents.

The proportion of respondents reporting any relapse from 2005 to 2010 did not differ across groups, but patients with wet OAB were more likely to report more than three relapses and PDDS progression. From 2005 to 2010, 55% of patients with wet OAB reported three or more relapses, compared with 51% of patients with dry OAB and 52% of patients with no OAB. In the same period, 37% of respondents with wet OAB reported progression, compared with 33% of respondents with dry OAB and 28% of respondents with no OAB. In addition, older age and longer disease duration were associated significantly with PDDS progression.

A higher proportion of patients with wet OAB in 2005 reported being severely bothered by urinary or bladder, bowel, and sexual dysfunction in 2010. Approximately 21% of respondents with wet OAB were severely bothered by urinary or bladder dysfunction in 2010, compared with 6% of patients with dry OAB and 5% of patients with no OAB. Eleven percent of patients with wet OAB were severely bothered by bowel dysfunction in 2010, compared with 5% of patients with dry OAB and 5% of patients with no OAB. In addition, 25% of participants with wet OAB were severely bothered by sexual dysfunction in 2010, compared with 5% of participants with dry OAB and 13% of participants with no OAB.

—Erik Greb

Is MS Associated With Schizophrenia and Bipolar Disorder?