Bipolar Disorder and Eating Disorders: A Comorbid Rollercoaster

In one study, comorbidity was linked
to more serious disease.

Bipolar disorder takes patients on a lifelong rollercoaster ride, from the highs of the manic phase to the lows of the depressive phase. Comorbidities can also obscure and delay the diagnosis. Three recent studies have focused on connections between bipolar disorder and eating disorders.

Aware that the percentage of patients with bipolar disorders who have comorbid eating disorders has been reported ranging from 2% to 15%, researchers at the Universidade Federal da Bahia, Porto Alegre, Brazil, wondered how having an eating disorder might affect a person with bipolar disorder. Dr. Camila Seixas and colleagues enrolled 356 bipolar patients in their study (Rev Bras Pisquitar 2012; 34:1516). All patients had undergone treatment between March 31, 2005 and March 22, 2009 at two university hospitals in Salvador and Porto Alegre, Brazil. These patients then completed a series of clinical and sociodemographic questionnaires. The World Health Organization Scale for quality of life evaluation was used for a subsample of 180 participants.

The researchers report that the prevalence of eating disorders was higher than in the general population, as other studies have reported. The mean age of study participants was 41 years. Among the study participants, 19 (5.3%) had a current of lifetime diagnosis of an eating disorder. Among the 19, 11 (57.9%) had bulimia nervosa (BN) and 8 (42.1%) had anorexia nervosa (AN). The authors found significant differences among bipolar patients with and without eating disorders, and the group with eating disorders contained a larger number of females than in the other group. The only male participant met the diagnostic criteria for BN. The authors also found that the odds of having an eating disorder increased with the number of comorbidities. And, as in previous studies, the authors found that eating disorders occurred more frequently during the depressive phase; both the HAM-D and the WHO Quality of Life Questionnaire were significant predictors of the presence of eating disorders in bipolar patients.

The study had several limitations: the cross-sectional study design precluded an opportunity to examine any temporal relationship between BD and eating disorders, body mass index (BMI) was not measured, and binge eating disorder (BED) was not included in the study because it is not included as a diagnostic category in the DSM-IV. Finally, all participants were adults. The authors suggest that future studies be designed to differentiate bipolar children and adolescents with comorbid eating disorders from the adult population.

Cormorbidity was associated with more severe illness

In an earlier study, Dr. S.L. McElroy and colleagues at the Lindner Center of HOPE, Mason, OH, reported that patients with bipolar disorder not infrequently have comorbid eating disorders, and this comorbidity is associated with an earlier age of onset and more severe course of bipolar illness (J Affect Disord 2011; 128:191). This particularly affects women. Of 875 outpatients with DSM-IV bipolar I or II disorders, 125 (14.3%) met criteria for at least one comorbid lifetime Axis I eating disorder; BED was more common (77 patients) than was BN (n=42) or AN (n=27). Having a lifetime comorbid eating disorder was associated with being female, and a host of other characteristics, including: younger age, earlier age of onset of mood symptoms and of bipolar disorder, history of rapid cycling and suicidal attempts, greater mean BMI, obesity and severe obesity and family history including depression, bipolar disorder, alcoholism, and drug abuse. Lifetime AN was associated with normal weight and a lifetime anxiety disorder, BN was associated with overweight, and lifetime BED was associated with obesity and severe obesity.

Future study will search the bipolar spectrum in eating disorders

Another Brazilian group at the University of San Paolo is conducting a study, ESPECTRA (Occurrence of Bipolar Spectrum Disorders in Eating Disorder Patients) and is currently enrolling patients in a single-site cross-sectional study designed to evaluate the prevalence of bipolar spectrum in a sample of eating disorders patients (BMC Psychiatry 2011; 11:59. Women 18 to 45 years of age will be evaluated. Stay tuned for results.