Author’s Accepted Manuscript Prevalence and correlates of bipolar disorders in patients with eating disorders Mei-Chih Meg Tseng, Chin-Hao Chang, Kuan-Yu Chen, Shih-Cheng Liao, Hsi-Chung Chen www.elsevier.com/locate/jad

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S0165-0327(15)30825-9 http://dx.doi.org/10.1016/j.jad.2015.10.062 JAD7838

To appear in: Journal of Affective Disorders Received date: 23 August 2015 Revised date: 15 October 2015 Accepted date: 23 October 2015 Cite this article as: Mei-Chih Meg Tseng, Chin-Hao Chang, Kuan-Yu Chen, Shih-Cheng Liao and Hsi-Chung Chen, Prevalence and correlates of bipolar disorders in patients with eating disorders, Journal of Affective Disorders, http://dx.doi.org/10.1016/j.jad.2015.10.062 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Abstract (249), text (3665), Tables (5, 1110)

Prevalence and correlates of bipolar disorders in patients with eating disorders Mei-Chih Meg Tseng1,2, Chin-Hao Chang3, Kuan-Yu Chen4, Shih-Cheng Liao2,5, Hsi-Chung Chen2,5, 1

Department of Psychiatry, Far Eastern Memorial Hospital, New Taipei City 22060, Taiwan; 2Department of Psychiatry, National Taiwan University College of Medicine, Taipei 10051, Taiwan; 3Department of Medical Research, National Taiwan University Hospital, Taipei, 10055, Taiwan; 4Department of Psychiatry, Taipei City Hospital, Songde Branch, Taipei 11080, Taiwan; 5Department of Psychiatry, National Taiwan University Hospital, Taipei 10002, Taiwan

Running title: Correlates of bipolar disorders in ED patients *Address for correspondence: Dr. Mei-Chih Meg Tseng No.21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City 22060, Taiwan (R.O.C.) E-mail: [email protected] Phone: 886-2-89667000 ext 1248: Fax: 886-2-23278630

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Background: To investigate the prevalence and correlates of bipolar disorders in patients with eating disorders (EDs), and to examine differences in effects between major depressive disorder and bipolar disorder on these patients. Methods: Sequential attendees were invited to participate in a two-phase survey for EDs at the general psychiatric outpatient clinics. Patients diagnosed with EDs (n = 288) and controls of comparable age, sex, and educational level (n = 81) were invited to receive structured interviews for psychiatric co-morbidities, suicide risks, and functional level. All participants also completed several self-administered questionnaires assessing general and eating-related pathology and impulsivity. Characteristics were compared between the control, ED-only, ED with major depressive disorder, and ED with bipolar disorder groups. Results: Patients with all ED subtypes had significantly higher rates of major depressive disorder (range, 41.3–66.7%) and bipolar disorder (range, 16.7– 49.3%) than controls did. Compared to patients with only EDs, patients with comorbid bipolar disorder and those with comorbid major depressive disorder had significantly increased suicidality and functional impairments. Moreover, the group with comorbid bipolar disorder had increased risks of weight dysregulation, more impulsive behaviors, and higher rates of psychiatric comorbidities. Limitations: Participants were selected in a tertiary center of a non-Western country and the sample size of individuals with bipolar disorder in some ED subtypes was small. 2

Conclusion: Bipolar disorders were common in patients with EDs. Careful differentiation between bipolar disorder and major depressive disorder in patients with EDs may help predict associated psychopathology and provide accurate treatment. Key words: anorexia nervosa, binge-eating disorder, bipolar disorders, bulimia nervosa, comorbidity, correlates, eating disorders

Introduction The co-existence of affective disorders and eating disorders (EDs) has been well documented in prior research (Godart et al., 2007). However, the relationship between ED and bipolar disorder has not gained much attention until recently (McElroy et al., 2006). A literature review indicated that the phenomenology, course, comorbidity, family history, and pharmacologic treatment response of bipolar disorders and EDs show considerable overlap between the two disorders, and further, that the overlap is particularly prominent when these disorders include full spectrum or subsyndromal definitions (McElroy et al., 2005). Misdiagnosis of bipolar spectrum disorders can have negative effects on the course of treatment, including more frequent occurrences of episodes (Ghaemi et al., 1980), increased risk of suicide (Berk and Dodd, 2005), and more severe role impairments (Angst et al., 2010) in general psychiatric patients 3

with depression, and similar conditions may occur in the ED population (McElroy et al., 2011b). There has been debate concerning the diagnosis of bipolar disorder, especially hypomania episodes, in terms of interview methods used (Benazzi and Akiskal, 2003), stem symptom recognition (Benazzi, 2004), and minimum duration of mania/hypomania symptoms (Angst et al., 2003). With the re-definition of the “soft bipolar spectrum”, some researchers have suggested that EDs, especially those that involve binging and purging behaviors, might belong to this spectrum disorder (Gamma et al., 2008; Perugi and Akiskal, 2002). With varied sample characteristics, assessment tools, and threshold criteria of bipolar disorder, lifetime prevalence rates of bipolar disorder in patients with ED in earlier studies have ranged from 0% to 19% in community or outpatient ED samples (Halmi et al., 1991; Hudson et al., 2007; Hudson et al., 1987; Javaras et al., 2008; Joyce et al., 2004; Lewinsohn et al., 1993; Simpson et al., 1992; Swanson et al., 2011), and 36% to 64% in ED inpatients (Hudson et al., 1988; McElroy et al., 2011b). One recently published article reported that 34.8% of patients with EDs had comorbidity with bipolar I and II disorders, and up to 68.1% had bipolar spectrum disorder (Campos et al., 2013). These studies tended to be limited by a small sample size (Campos et al., 2013; Halmi et al., 1991; Hudson et al., 1987; Simpson et al., 1992), lack of a control group (Campos et al., 4

2013; Simpson et al., 1992), use of a relatively strict interview method for diagnosis of bipolar disorders (McElroy et al., 2011b), i.e., the Structure Clinical Interview for the DSM-III-R or IV (SCID) (Benazzi and Akiskal, 2003), and restriction to one specific ED group (Hudson et al., 1988; Javaras et al., 2008; Joyce et al., 2004). While several studies have examined the effects of EDs on bipolar disorder patients (McElroy et al., 2011a; Wildes et al., 2008), little is known about the effects of bipolar disorders on patients with EDs. Two studies found that self-destructive behavior in patients with EDs is associated with bipolar disorder (Favaro et al., 2008; Stein et al., 2004). One study reported that comorbidity with bipolar disorders is associated with higher family income, proportion of married people, and comorbidity with substance use (Campos et al., 2013). The present paper aims to investigate the prevalence and correlates of bipolar disorders in ED patients as assessed with a structured clinical interview. We hypothesize that bipolar disorder is more prevalent among ED patients compared to control participants, and that the presence of a bipolar disorder comorbidity is associated with increased risks of being overweight, general pathology, suicide and other impulsive behaviors, co-morbidities with other psychiatric disorders, and impaired work performance. Considering the potentially discriminative effects between comorbid major depressive disorder and comorbid bipolar disorder on patients with EDs, we also included individuals with comorbid 5

major depressive disorder along with an ED-only group and a control group to compare the above variables.

Methods Participants and procedures The participants were patients with EDs aged 18–45 who were enrolled consecutively from the general outpatient clinics of the Department of Psychiatry at a teaching hospital via a two-phase method from August 2010 to July 2014. Patients with active psychotic conditions, organic mental disorders, mental retardation, and severe physical conditions were excluded from participation in phase one screening. Each psychiatric outpatient who agreed to participate completed a brief paper-form screening questionnaire (SCOFF) (Liu et al., 2015) and was interviewed by one of two trained research assistants using the ED Module of the Structured Clinical Interview for DSM-IV-TR Axis I disorders Patient version (SCID-I/P) (First et al., 2002). The SCOFF comprises five dichotomous questions regarding binge eating, purging, and body dissatisfaction (Morgan et al., 1999) and the name “SCOFF” is the acronym from the five questions. In total, 2306 patients completed the diagnostic procedure and the participation rate of men and women was 96.9% and 96.4%, respectively. Of them, 288 ED patients completed the rest of the study with a 6

completion rate of 90.1% for those who consented to participate. Age, gender, and educational level comparable controls without EDs (confirmed by the SCID-I/P) were enrolled from the advertisement via internet or fliers. Both patients (n = 288) and controls (n = 81) received further face-to-face interviews, assessing co-morbid psychiatric diagnosis, suicidality, and functional impairment. Diagnostic raters were one psychiatrist and two research assistants with college degrees in psychology. The diagnostic raters were highly trained and monitored throughout the study period to minimize rater drift. Participants also completed several questionnaires concerning eating pathology, general psychopathology, and impulsivity. The Institutional Review Board of National Taiwan University Hospital approved this study. Measures SCID-I/P An ED diagnosis in last 3 months and further in the past was established by the SCID-I/P. This study was conducted during the period of transition from the DSM-IV to the DSM-5, and we adopted the relaxed criteria of EDs according to the modification (Wilson and Sysko, 2009). Patients were not required to meet the anorexia nervosa (AN) criteria for amenorrhea and the minimal frequency and duration of bulimia nervosa (BN) and binge-eating disorder (BED) was once per week for 3 months. These were consistent with the revised criteria of AN, BN and BED in 7

the DSM-5 (American Psychiatric Association, 2013). We paid special attention to the frequency and the duration of binge eating and recorded the exact frequency and duration of binge eating occurred in order to re-assign their ED diagnosis according to the different threshold criteria from the DSM-IV to the DSM-5. Participants who reported extreme weight or shape concerns, regular binge-eating symptoms without adequate frequency or without feeling distress about binge eating, and those who did not meet criteria for the previous three disorders were diagnosed with ED, not otherwise specified (EDNOS). Mini International Neuropsychiatric Interview (MINI) The MINI is a short structured diagnostic interview for the DSM-IV and ICD-10 psychiatric disorders (Sheehan et al., 1998). It is divided into many modules including diagnoses of major depression, bipolar disorder, anxiety disorders, alcohol use disorder, and substance use disorders. Interviews of the first 40 participants were audiotaped. The k coefficients of inter-rater reliability for all diagnoses were 0.60 (social phobia) to 1.00 (major depressive episode) except substance use disorder (0.47). Assessment of functional impairment and suicide risks The 87-item SIAB-EX covers a wide range of symptoms frequently seen in EDs—body image disturbances, bulimic symptoms, social integration problems,

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problems associated with sexuality, depression, compulsion, and anxiety (Fichter and Quadflieg, 2001). Each item was rated for present status (the last 3 months) and for maximum pathology in previous years (lifetime). Responses were rated on a severity scale, ranging from 0 for “symptom not present” to 4 for “symptom very much/very severely present.” Following an independent translation of the Chinese version of the SIAB-EX by a professional translator, all items were reviewed by two psychiatrists (Tseng MM and Chen KY). The assessment of functional impairment was adopted from item 53, “Was your work performance objectively impaired at work or in your household?”. Suicide risks were rated by item 68, ’Did you think about commit suicide in the last 3 months or in the past?’, item 69, ‘Did you ever attempt to commit suicide?’, and Item 70, ‘Did you ever hurt yourself intentionally?’. Severity of suicidal acts and auto-aggressive behaviors is rated according to the number of attempts or seriousness of physical injury. Bulimic Investigatory Test Edinburgh (BITE) This self-reported measure includes the Symptom Scale (30 items) and the Severity Scale (6 items) (Henderson and Freeman, 1987). The Chinese BITE has good internal consistency (Cronbach’s a = .78 and .52, respectively) and test-retest reliability (intra-class correlation reliability of .86 and .88, respectively) for the two scales (Tseng et al., 2014). 9

Body Shape Questionnaire (BSQ) The BSQ was initially developed as a 34-item questionnaire for assessing feelings about body shape and the behavioral and emotional consequences of such feelings. The BSQ-8 used in this study, which has 8 items derived from the Chinese BSQ-34 (Tseng et al., 2007), has good internal consistency (Cronbach’s alpha, a = .88). State-Trait Anxiety Inventory (STAI) The STAI uses a 4-point Likert format containing 40 items (20 state-anxiety items, 20 trait-anxiety items). In this study, Cronbach’s a of the State Anxiety and Trait Anxiety subscales was .93 and .91, respectively. Affect Lability Scale (ALS) The ALS is a 54-item scale in which people rate their agreement with statements regarding the tendency of their mood to shift between what they consider normal mood to the affective domains of anger, depression, elation, and anxiety, as well as their tendency to oscillate between depression and elation and between depression and anxiety (Harvey et al., 1989). Oliver and Simons created an 18-item short form (ALS-18) by selecting items using exploratory factor analysis with eigenvalues greater than 1 (Oliver and Simons, 2004). The preliminary test showed excellent internal consistency for the Chinese version of the ALS-18 (Cronbach a = .93). The 10

item-total correlations ranged from .37 to .76. Barratt Impulsiveness Scale (BIS) This is a 30-item self-report questionnaire measuring trait impulsivity (Patton et al., 1995). The Chinese version of BIS-11 (BIS-11-CH) is modified from the original BIS by removing the five items (item 15, 21, 23, 27, and 29) with poor item-total correlations (less than .1) (Li and Chen, 2007). The remaining 25 items of the BIS-11-CH had a Cronbach a of .83 and an intact factorial structure of inability to plan (factor 1), lack of perseverance and self-control (factor 2), and propensity toward novelty-seeking and acting without thinking (factor 3) (Li and Chen, 2007). Impulsive Behavior Scale (IBS) The self-reported IBS scale assesses the degree to which an individual displays 25 impulsive behaviors (Rossotto et al., 1994). The frequency of each behavior is rated on a 5-point Likert-type scale. The item mean score provides a global level of impulsive behaviors, where impulsivity increases as scores increase. Internal consistency (Cronbach’s a = .87) of the IBS for this sample was good. Statistical analysis Patients with EDs and control participants were grouped according to the presence of EDs and comorbid lifetime affective disorders, i.e., controls, ED only, ED with major depressive disorder, and ED with bipolar affective disorder. Descriptive 11

statistics were computed to determine means and standard deviations of all continuous variables and frequency distributions for categorical variables. The differences in continuous variables between groups were compared using an ANOVA and Scheffé’s test for post-hoc comparisons. For categorical variables, frequency differences were compared using the chi-square test or Fisher’s exact test. Logistic regression was employed to estimate odds ratios (ORs) with 95% confidence intervals (CIs). All tests were two-tailed, and p < .05 was considered significant. Statistical analysis used SAS 9.2 (SAS Institute, Inc., Cary, NC, USA).

Results Demographics and body weight history Table 1 shows the comparison of demographics and body weight information between the ED-only (11.5%), ED with comorbid major depressive disorder (52.8%), ED with comorbid bipolar disorder (35.8%), and control groups. No statistically significant differences in age, gender, and educational levels were observed between different ED groups and the control group. Patients with ED and comorbid bipolar disorder tended to have the highest body weight at present and in the past. Rates of comorbid lifetime affective disorders The diagnostic distribution of AN, BN, BED, and EDNOS was 54 (18.8%), 125 12

(43.4%), 75 (26.0%), and 34 (11.8%), respectively (Table 2). Patients with all ED subtypes had significantly higher rates of major depressive disorder (range, 41.3– 66.7%) and bipolar disorder (range, 16.7–49.3%) than controls did. Binge eating disorder had the highest rate of comorbidity with bipolar disorder among groups. Notably, the comorbidity rate of different ED subtypes with bipolar II disorder was significantly higher than that of the control group, except for patients with AN. Severity of eating and general psychopathology There was no statistically significant difference in age at onset of eating symptoms for the ED-only (18.3 ± 5.1 year-old), ED with major depressive disorder (20.1 ± 6.0 year-old), or ED with bipolar disorder groups (19.5 ± 6.1 year-old; P = .29). The ED-only and ED with comorbid affective disorders groups had a significantly higher degree of severity in eating and general psychopathology than did controls, with a few exceptions (Table 3). No statistically significant difference in binge-eating severity was found among ED groups, but the ED with comorbid bipolar disorder group had higher body image concern than did the ED-only group. Both ED groups with comorbid affective disorders showed consistently more severe degrees of anxiety and depression as compared to the ED-only group. Moreover, the group with comorbid bipolar disorder had a more severe degree of affective lability and impulsiveness than did the groups with comorbid major depressive disorder and only 13

ED. Comorbidity with other DSM-IV psychiatric disorders Compared with the ED-only group, ED with comorbid bipolar disorder patients had significantly higher rates of social phobia, panic disorder, agoraphobia, and obsessive-compulsive disorder (Table 4). Moreover, ED with comorbid bipolar disorder patients had significantly higher rates of panic disorder, agoraphobia, generalized anxiety disorder, and alcohol use disorder than did the group with comorbid major depressive disorder. No statistically significant difference in comorbidity rate was found between the ED-only group and the ED group with comorbid major depressive disorder. Severity of role impairment and suicide risks Both ED groups with comorbid affective disorders had significantly more severe degrees of functional impairments and suicide risks as compared to the ED-only group (Table 5). But there was no statistically significant difference in degrees of functional impairments and suicidality between ED with major depressive disorder and ED with bipolar disorder groups.

Discussion Using a two-phase method investigating EDs at general psychiatric clinics, we 14

found that more than half of the clinical ED patients were comorbid with major depressive disorder, and more than one third of them had comorbid bipolar disorder. The ED with comorbid bipolar disorder group tended to have a higher body weight, greater body image concern, and more emotional difficulties, and had significantly increased suicidality, impulsive behaviors, psychiatric co-morbidities, and impaired role functioning. Patients with comorbid major depressive disorder also had significantly more severe degrees of anxiety and depression and increased suicidality and functional impairment as compared to the ED-only group, but did not have higher rates of comorbid psychiatric diagnoses or a more severe degree of impulsivity. Neither bipolar disorder nor major depressive disorder had effects on age of onset of disordered eating and binge-eating severity. The rate of comorbid bipolar disorder in our ED sample is at the higher end compared to earlier studies. With reference to the increase in the prevalence of bipolar spectrum disorder in epidemiological studies (Benazzi, 2007; Merikangas et al., 2011), we speculated that the higher co-occurring rates of all bipolar disorders in our study might be explained in part by the comparably high prevalence rate of bipolar II disorder, which parallels the findings in the general population. The other possible reasons included different case enrollment method, relaxed screening questions for mania/hypomania in the MINI, and the loosened diagnostic criteria of threshold ED 15

diagnosis. In contrast to other studies in which most ED cases were referred for obvious ED problems, patients who presented with any psychiatric problems but with hidden ED morbidity might be detected via the two-phase method applied in this study. It was estimated that only 17.3-45.8% of individuals with EDs sought help for an eating problem (Hudson et al., 2007; Mond et al., 2007; Striegel-Moore et al., 2001). Most studies have found no significant differences in the rates of major depressive disorder across diagnostic types of EDs (Godart et al., 2007), but bipolar spectrum disorders seem to be more common in BN and BED (range, 11– 26%)(Hudson et al., 2007; Javaras et al., 2008; Lewinsohn et al., 2000) than they are in AN (range, 0–13%)(Fogarty et al., 1994; Halmi et al., 1991; Hudson et al., 2007; Ivarsson et al., 2000; Swanson et al., 2011; Wildes et al., 2007). In line with the prior research, our study demonstrated that all ED subtypes had significantly higher rates of major depressive disorder and bipolar disorders than did controls, except that AN did not have a higher rate of bipolar II disorder. Nearly half of the BED patients co-occurred with bipolar disorder in this study. One study found that Asian Americans are less likely than Whites to endorse BED symptoms related to distress or loss of control (Lee-Winn et al., 2014). We assumed that Taiwanese BED patients seen in a tertiary psychiatric care service represent a subgroup with more complex 16

affective and behavioral disturbances that led them to seek help only when pervasive symptoms developed. One study addressed the role of affective lability in the development of binge eating (Greenberg and Harvey, 1987). Another study found that individuals with BN experiencing labile emotions were associated with indicators of dysregulated behavior, suggesting that higher levels of affective lability predict a more severely dysregulated behavioral profile (Anestis et al., 2009). With a different approach, our study raised the speculation that affect lability, binge eating, and other impulsive behaviors co-occur as a sub-phenotype instead of causal relationship among them. The presence of both major depressive disorder and bipolar disorder had negative effects on role functioning, and was associated with increased suicidality in patients with EDs. Moreover, comorbid bipolar disorder showed increased risks of weight gain, mood lability, poor impulse control, and had more psychiatric co-morbidities. A previous comparison of currently depressed unipolar and bipolar patients revealed no differences in terms of symptom severity or social impairment (Dorz et al., 2003), with the exception that bipolar depressed patients might exhibit greater mood variability (Ahearn and Carroll, 1996) and experience hyperphagia or weight gain (Mitchell et al., 2008). Investigations of community samples demonstrate that those with major depression and subthreshold bipolar disorder show greater 17

comorbidity with anxiety, impulse control, and alcohol/substance use disorders (Angst et al., 2010; Merikangas et al., 2011; Zimmermann et al., 2009). Our study successfully demonstrated the differential effects between bipolar disorder and major depressive disorder and replicated the effects of bipolar disorder on patients with EDs. Accurately and differentially diagnosing bipolar disorder from major depressive disorder in ED patients seeking treatment may help determine if combination use of mood stabilizers or antipsychotics is necessary (Pacchiarotti et al., 2013). The presence of EDs has been implicated as a marker of clinical severity in patients with bipolar disorders, and this comorbidity is associated with an earlier age of onset and more severe course of bipolar illness (Brietzke et al., 2011; McElroy et al., 2011a). In contrast, in the present study, the presence of bipolar disorder in patients with EDs indicated more severe functional impairment, but had no significant effect on the age at onset of ED symptoms and severity of binge eating. This finding echoes that of our earlier study and other studies using latent class analysis that the existence of an impulsive subgroup of ED patients had higher levels of general pathology and anxiety disorders, child abuse, and other impulsive behaviors, and further, that this subgroup failed to differ in bulimic behavior with other groups without such associated pathology (Myers et al., 2006; Tseng and Hu, 2012). With different study population, our results are parallel with the findings in a recently published paper that comorbid 18

BED was associated with greater risks of suicidality, psychosis, mood instability, anxiety disorder comorbidity, and substance abuse comorbidity in patients with bipolar disorders, and the authors suggested that bipolar patients with BED may represent a sub-phenotype of bipolar disorder (McElroy et al., 2013). The relationship between EDs and bipolar disorders can both be distinct based on a categorical approach wherein the age at onset and severity of binge eating is independent from the effect of comorbid bipolar disorder, as well as related based on a dimensional approach wherein both groups have higher levels of eating and emotional pathology compared to control participants, as derived from our current study. The underlying mechanisms responsible for distinct disordered eating and the effect of emotional process on disordered eating require further investigation. The current findings should be interpreted in view of several methodological limitations. First, participants were selected in a tertiary center of a non-Western country, and thus, the sample may not be representative of the population of individuals with EDs elsewhere. However, we selected ED patients in a large sample of general psychiatric outpatients using a two-phase method and its high response rate that might avoid selection bias resulting from participants attending specialized ED units in earlier studies or high attrition rate in many Western studies. The sample size of individuals with bipolar disorder in some ED subtypes was small, and accordingly, 19

all types of bipolar disorder were included in the same group. We did not go further to analyze if there was a difference in effect on EDs between individuals with bipolar I and bipolar II disorder. Finally, as only bipolar disorder diagnoses were included in the analysis, specific symptoms of hypomania/mania symptoms should be evaluated in subsequent studies. In summary, bipolar disorders are not uncommon in patients with EDs. The presence of comorbid bipolar disorder may increase risks of weight dysregulation, suicide, and other psychiatric comorbidities, as well as impair role functioning in patients with EDs. Carefully identifying the presence of comorbid bipolar disorder will allow for appropriate treatment consideration.

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Acknowledgements: Data collection of this study was supported by grants from the National Science Council of Taiwan (NSC 99-2410-H-002-094 and 100-2410-H-002 -039 -MY2), and manuscript preparation was supported by two more grants (NSC 102-2410-H-002 -047 and FEMH 103-2314-B-418 -010). The authors acknowledge statistical assistance provided by the Taiwan Clinical Trial Bioinformatics and Statistical Center, Training Center, and Pharmacogenomics Laboratory (Which is founded by National Research Program for Biopharmaceuticals (NRPB) at the Ministry of Science and Technology of Taiwan; MOST 103-2325-B-002-033). And the Department of Medical Research in National Taiwan University Hospital.

Disclosure The authors report no competing interests.

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Highlights · ·

We used two-phase survey for eating disorder in the psychiatric outpatients We examine the correlates of bipolar disorders in outpatients with eating disorders.

·

ED Patients had significantly higher rates of bipolar disorder than controls did. Comorbidity with bipolar disorder increased risks of suicide and impairments.

·

It increased risks of more impulsive behaviors and psychiatric comorbidities

·

31

12.9

Highest parental education (yrs) 22.9 19.6

2 **

2.4

3.5

3.4

4.0

2.4

6.7

18.0

25.9

21.0

12.7

14.4

25.9

4.1

4.7

5.7

3.0

2.7

7.1

16.9

23.8

20.4

12.8

14.5

27.4

3.4

4.9

4.7

4.2

2.2

7.3

141 (92.8)

with MDD (2) (n = 152)

Eating disorders

18.6

26.4

23.6

12.6

14.1

28.0

3.4

6.2

5.8

4.6

2.6

7.7

84 (81.6)

(n = 103)

Eating disorders with BAD (3)

< .001

< .001

< .001

.981

.051

.184

¾

¾

¾

3 > 2; 3 > 4; 1> 4 3 > 2; 4 > 2

3>2

2 & 3*

Comparison*

Value .038

Post hoc

P

Values are N (%) or mean ± SD * using Scheffe test, The percentage of female gender was significantly different between eating disorders with MDD and eating disorders with BAD

BMI: Body mass index; MDD: major depressive disorder; BAD: bipolar affective disorder

BMI, minimal (kg/m )

BMI, maximal (kg/m )

2 **

BMI, current (kg/m )

21.5

15.1

Education (yrs)

2 *

25.9

29 (87.9)

(n = 33)

(n = 81) 74 (91.4)

only (1)

group (4)

Age (yrs)

Gender, female (N, %)

Eating disorders

Control

Table 1. Demographics and body weight for eating disorder patients and controls

10 (12.3)

46 (85.2)

1 (1.9)

3 (5.6)

6 (11.1)

9 (16.7)

36 (66.7)

4

1, 2, 3 > 4

Post hoc Comparison

4 (12.1) 4 (12.1) 4 (12.1)

Agoraphobia

Obsessive compulsive disorder Post-traumatic stress disorder 5 (15.2)

26 (17.1)

5 (3.3)

43 (28.3) 18 (11.8)

28 (18.4)

48 (31.6) 17 (11.2)

51 (33.6)

N (%)

21 (20.4)

26 (25.2)

36 (35.0) 16 (15.5)

31 (30.1)

41 (39.8) 27 (26.2)

48 (46.6)

N (%)

with BAD (3) (n = 103)

disorders

Eating

MDD: major depressive disorder; BAD: bipolar affective disorder OR, odds ratio; CI, confident interval Values in bold type indicated statistically significant

Drug abuse/dependence

0 (0)

6 (18.2) 1 (3.0)

Social phobia Panic disorder

Alcohol abuse/dependence

9 (27.3)

N (%)

disorders with MDD (2) (n = 152)

disorders only (1) (n = 33)

Generalized anxiety disorder

Comorbid diagnosis

Eating

Eating

2.3 (1.0, 5.5)

OR (95% C.I.)

3 vs.1

¾ 1.2 (0.4, 3.3)

2.9 (0.9, 8.6) 1.0 (0.3, 3.1) ¾ 1.4 (0.5, 4.2)

3.9 (1.3, 11.9) 1.3 (0.4, 4.3)

2.1 (0.8, 5.4) 3.0 (1.1, 7.8) 4.0 (0.5, 31.4) 11.4 (1.5, 87.3) 1.6 (0.5, 5.0) 3.1 (1.0, 9.6)

1.3 (0.6, 3.1)

OR (95% C.I.)

2 vs.1

9.9 (3.7, 26.9) 1.2 (0.7, 2.4)

12.2 (4.5, 32.8) 1.3 (0.7, 2.4)

2.1 (1.2, 3.6) 1.6 (0.9, 2.7) 1.4 (0.7, 2.7)

3.3 (1.7, 6.3)

2.8 (1.4, 5.5) 1.9 (1.1, 3.4) 1.4 (0.8, 2.3) 1.4 (0.7, 2.8)

1.8 (1.1, 3.0) 1.6 (1.0, 2.7)

OR (95% C.I.)

3 vs. 1+2

1.7 (1.0, 2.9) 1.4 (0.9, 2.4)

OR (95% C.I.)

3 vs.2

Table 4. Comparison of lifetime psychiatric diagnoses among eating disorder patients with comorbid affective disorders

0.2

0.6 0

2.0

0.6

0.7 0

1.2

SD

0.8

1.4 0.5

2.5

M

1.0

1.7 0.8

2.7

M

1.1

1.1 1.2

1.0

SD

(n = 103)

with BAD (3)

Eating disorders

.002

< .001 < .001

.003

Value

P

2, 3 > 1

2, 3 > 1 2, 3 > 1

2, 3 > 1

Post hoc Comparison

All impairments were assessed using the Structured Interview on Anorexic and Bulimic Disorder, Expert-Assessment (SIAB-EX) a: rated by the Item 53 ‘Was your work performance objectively impaired at work or in your household ?”. Severity of impairment is rated from 0 (=no) to 4 (=very severe); b: rated by the item 68 ’Did you think about commit suicide in the last 3 months or in the past?’; c: rated by the item 69 ‘Did you ever attempt to commit suicide?’; d: rated by the Item 70 ‘Did you ever hurt yourself intentionally?’. Severity of suicidal acts and auto-aggressive behaviors is rated from 0 (= symptom not present) to 4 (= symptom very much/very severely present) according to the number of attempts or seriousness of physical injury;

1.1

1.2 1.0

1.0

SD

(n = 152)

(n = 33) M

with MDD (2)

only (1)

MDD: major depressive disorder; BAD: bipolar affective disorder

Auto-aggressive behaviorsd

Suicidal thoughts Suicidal actsc

b

Functional impairment

a

Eating disorders

Eating disorders

Table 5. Comparison of suicide risk and functional impairment among eating disorder patients with comorbid affective disorders