Those with comorbid EDs were more likely to be female and to have BD-II subtype. Their presentations were also more complicated and included a history of suicidality, additional psychiatric conditions, smoking, and a history of sexual abuse, as well as more severe depression and emotional instability.
“We think the take-home message is that, in addition to other more recognized psychiatric comorbidities, youth with BD are also vulnerable to developing EDs. Thus, clinicians should be routinely monitoring for eating, appetite, and body image disturbances when working with this population,” lead author Diana Khoubaeva, research analyst at the Centre for Youth Bipolar Disorder, Centre for Addiction and Mental Health, Toronto, and senior author Benjamin Goldstein, MD, PhD, director of the Centre for Youth Bipolar Disorder, wrote in an e-mail to this news organization.
“Given the more complicated clinical picture of youth with co-occurring BD and EDs, this combination warrants careful attention,” the investigators note.
The study was published online May 11 in the Journal of Clinical Psychiatry.
Lack of research
“From the existing literature, we learned that EDs are not uncommon in individuals with BD, and that they are often associated with a more severe clinical profile,” say the researchers. “However, the majority of these studies have been limited to adult samples, and there was a real scarcity of studies that examined this co-occurrence in youth.”
This is “surprising” because EDs often have their onset in adolescence, so the researchers decided to explore the issue in their “fairly large sample of youth with BD.”
To investigate the issue, the researchers studied 197 youth (aged 13-20 years) with a diagnosis of BD (BD-I, BD-II, or BD-NOS) who were recruited between 2009 and 2017 (mean [standard deviation] age, 16.69 [1.50] years; 67.5% female).
ED diagnoses included both current and lifetime AN, BN, and ED-NOS. The researchers used the Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children, Present and Lifetime Version (K-SADS-PL) to determine the diagnosis of BD.
They also collected information about comorbid psychiatric disorders, as well as substance use disorders and cigarette smoking. The Life Problems Inventory (LPI) was used to identify dimensional borderline personality traits.
Information about physical and sexual abuse, suicidal ideation, nonsuicidal self-injury (NSSI), and affect regulation were obtained from other measurement tools. Participants’ height and weight were measured to calculate body mass index.
Neurobiological and environmental factors
Of the total sample, 24.84% had received a diagnosis of ED in their lifetime.
Moreover, 28.9% had a lifetime history of binge eating. Of these, 17.7% also had been diagnosed with an ED.
Participants with BD-II were significantly more likely than those with BD-I to report both current and lifetime BN. There were no significant differences by BD subtype in AN, ED-NOS, or binge eating.
Higher correlates of clinical characteristics, psychiatric morbidity, treatment history, and dimensional traits in those with vs. those without an ED are detailed in the accompanying table.
The ED group scored significantly higher on all LPI scores, including impulsivity, emotional dysregulation, identity confusion, and interpersonal problems, compared to those without an ED. They also were less likely to report lifetime lithium use (chi2 = 7.9, P = .01).
Multivariate analysis revealed that lifetime EDs were significantly associated with female sex, history of cigarette smoking, history of individual therapy, family history of anxiety, and LPI total score and were negatively associated with BD-I subtype.
“The comorbidity [between EDs and BD] could be driven by both neurobiological and environmental factors,” Dr. Khoubaeva and Dr. Goldstein noted. EDs and BD “are both illnesses that are fundamentally linked with dysfunction in reward systems – that is, there are imbalances in terms of too much or too little reward seeking.”
They added that individuals affected by these conditions have “ongoing challenges with instability of emotions and ability to manage emotions; and eating too much or too little can be a manifestation of coping with emotions.”
In addition, medications commonly used to treat BD “are known to have side effects such as weight/appetite/metabolic changes, which may make it harder to regulate eating, and which may exacerbate preexisting body image challenges.”
The researchers recommend implementing trauma-informed care, assessing and addressing suicidality and self-injury, and prioritizing therapies that target emotional dysregulation, such as dialectical behavioral therapy.