Body Dysmorphic Disorder and Major Depressive Episode Have Comorbidity-Independent Associations With Suicidality in an Acute Psychiatric Setting

Introduction

Internalizing disorders, such as mood and anxiety disorders, are major risk factors for suicidal ideation and behavior (Bentley et al., 2016; Nock et al., 2009, 2010; Sareen et al., 2005). Internalizing disorders frequently co-occur, and it is, therefore, important to determine to what extent individual disorders are uniquely related to suicidality, after adjusting for the effects of co-occurring disorders. Evidence from community samples suggests that mood disorders, trauma-related disorders, obsessive-compulsive disorder (OCD) and to a lesser extent most anxiety disorders, remain independent predictors of suicidal ideation and behaviors even after controlling for the effects of comorbid disorders (Fernández de la Cruz et al., 2017; Nock et al., 2009, 2010; Sareen et al., 2005).

Studies have shown that predictors of suicidality can differ between community and clinical samples (e.g., Brown et al., 2000; Grøholt et al., 2000). However, surprisingly, little is known about the unique relationship between individual diagnoses and suicidality in psychiatric populations. Understanding this relationship is important because in psychiatric settings the risk for suicidality is high and psychiatric diagnoses are often known. Existing evidence from clinical populations suggests that major depressive disorder, bipolar disorder and posttraumatic stress disorder (PTSD) may have unique associations with suicidal ideation and behaviors (Beautrais et al., 1996; Brown et al., 2000; Chioqueta and Stiles, 2003; Marshall et al., 2001; Naragon-Gainey and Watson, 2011). However, the studies to date have been limited by an exclusive focus on a specific disorder (e.g., depressed patients), or by not adequately adjusting for coexisting disorders. In addition, studies on suicidality in internalizing disorders typically do not assess OCD and body dysmorphic disorder (BDD), two severe obsessive-compulsive spectrum disorders (Weingarden et al., 2016) that often co-occur with anxiety and mood disorders (Bjornsson et al., 2010). The absence of BDD from this literature is noteworthy because this disorder is quite prevalent in community, medical and psychiatric settings (Greenberg et al., 2019; Veale et al., 2016), and existing data suggest high rates of suicidality among these patients (Angelakis et al., 2016; Phillips et al., 2005), even when compared to patients with other psychiatric disorders (Phillips and Menard, 2006; Phillips, 2017).

In the current study, we examined whether mood, anxiety, and obsessive-compulsive spectrum disorders (OCD and BDD) were associated with suicidal ideation and behaviors in an acute psychiatric sample. Patients were evaluated during admission to psychiatric treatment in a partial hospital program. Semi-structured interviews were used to assess current psychiatric diagnoses and past-month history of suicidal ideation and suicidal behaviors (i.e., actual, aborted, or interrupted suicide attempts, or preparatory behavior imminently preceding a suicide attempt). We conducted both bivariate (each disorder examined separately) and multivariate (all disorders examined simultaneously) analyses to investigate the associations between the psychiatric disorders and suicidality. Based on prior work in community and clinical samples, we hypothesized that unipolar depression, bipolar depression, PTSD, and BDD would all have unique associations with suicidal ideation and behaviors even after controlling for comorbid disorders in the multivariate analyses.

Method

Participants and treatment setting

Participants were patients admitted to the Behavioral Health Partial Program at McLean Hospital. Most patients in the program have mood and anxiety disorders. The program provides brief (one to two weeks) treatment focused on stabilizing acute symptoms. Patients attend the program every weekday (9 am–3 pm) and receive group and individual psychotherapy as well as pharmacotherapy. The sample included 498 patients (female: n = 275, 55.2%; male: n = 223, 44.8%) with an average age of 34.8 years (SD = 14.4, range = 18–74). The sample was almost exclusively non-Hispanic (94.1%) and the majority (88%) identified as White/Caucasian; 8% as Asian, 3% as Black/African American, and 4% as other races. One half (48.7%) was referred from inpatient hospitalization, and the other half from outpatient providers.

Measures

Psychiatric diagnoses

The Miniature International Neuropsychiatric Interview (MINI) for DSM-IV (Sheehan et al., 1998) was used to assess the diagnoses for all the disorders, except BDD. The MINI is a semi-structured diagnostic interview that has been shown to have good psychometric properties, including excellent to outstanding interrater reliability for mood and anxiety disorders (Sheehan et al., 1998). The following modules were analyzed in the study: Major depressive episode (MDE), panic disorder, agoraphobia, social anxiety disorder, posttraumatic stress disorder, obsessive-compulsive disorder, and generalized anxiety disorder. We also assessed current and past history of mania, hypomania and hypo-mania symptoms to distinguish between bipolar and unipolar depression. A diagnosis of BDD was assessed with a revised version of the body dysmorphic disorder diagnostic module (Phillips, 2005), a semi-structured interview designed to assess diagnosis of BDD. We used a revised version (Bjornsson et al., 2016) of the interview that assesses DSM-5 criteria for BDD (the revision was done in collaboration with Dr. Katharine A. Phillips, the author of the interview).

Suicidality

The Columbia Suicide Severity Rating Scale (C-SSRS; Posner et al., 2011) was used to assess suicidal ideation and suicidal behaviors in the past month. The C-SSRS is a widely used semi-structured interview with good psychometric properties designed to assess suicidal ideation and behaviors (Posner et al., 2011). Suicidal ideation was assessed on a 6-point severity scale: (0) no ideation, (1) wish to be dead, (2) nonspecific active suicidal thoughts, (3) suicidal thoughts with methods, (4) suicidal intent, and (5) suicidal intent with plan. The most severe ideation in the past month was coded for each participant. The scale was dichotomized to reflect absence (score = 0) or presence (score = 1–5) of ideation in the past month. The suicide behavior scale documents four discrete suicidal behaviors in the past month: actual suicide attempts, aborted suicide attempts, interrupted suicide attempts, and preparatory behaviors (e.g., collecting pills) imminently preceding an attempt. Following previous work (e.g., Hesdorffer et al., 2013), the presence of suicidal behavior was coded if a patient reported behaviors in at least one of the four categories. The scale also includes an item that assesses presence of non-suicidal self-injury in the past month (see Table S1 in supplementary materials).

Interviewers were graduate-level clinical trainees (PhD or masters students) who were trained specifically in administering the interviews. Clinical psychologists provided the training, which included didactics, mock interviews, ratings of audiotaped training interviews and monthly supervision in which assessment issues, such as differential diagnoses, were discussed.

Data analyses

All analyses were conducted in SPSS-24. We compared the prevalence of psychiatric diagnoses and suicidality between males and females using chi-square tests. Multiple logistic regression analyses were used to examine the associations psychiatric diagnoses had with suicidal ideation and suicidal behaviors (1 = presence of suicidality; 0 = absence of suicidality). Odds ratios (ORs) and 95% confidence intervals (CI) were calculated for each predictor. We performed bivariate analyses (each predictor modeled individually) and multivariate analyses (all predictors modeled simultaneously) with suicidal ideation and suicidal behaviors as outcomes (See Table S1 in supplementary material for analyzes with non-suicidal self-injury as an outcome).

We first examined the effects of MDE before considering the effects of unipolar and bipolar depression separately. Participants meeting criteria for MDE were divided into unipolar and bipolar depression groups based on current or lifetime history of mania, hypomania or hypomania symptoms (bipolar depression also included mixed episodes). This yielded unipolar depression and bipolar depression variables that capture mutually exclusive groups (i.e., a person cannot have both diagnosis). Because they were mutually exclusive we decided not to enter the two variables simultaneously as predictors. Thus, after conducting regression analyses with MDE as a predictor, we repeated all the analyses with either unipolar or bipolar depression as a predictor instead of MDE. Age and gender were controlled for in all models.

Procedure

Data were collected over a one-year period, from 7/2016 to 7/2017. For patients who admitted to the program more than once during the study period, only data from the first admission were included. The sample included consecutively admitted patients, although a substantial minority did not complete the interviews due to logistic or clinical reasons (24%). Excluded patients did not differ from the study sample with respect to age, gender ratio, race or ethnicity (Table S2 in supplementary material). Also, the two groups did not differ in selfreported negative affect, substance use problems or suicidality/self-harm; however, excluded patients had higher scores on self-reported relationship problems and psychosis (Table S2). Patients underwent the semi-structured interviews as part of routine clinical evaluation (on day 2 of the treatment), and the study was approved as an exempt protocol (using de-identified dataset) by the hospital's institutional review board.

Results

Table 1 shows the prevalence of psychiatric disorders and suicidality for males and females in the sample. Female patients had higher rates of all the psychiatric disorders assessed, except for bipolar depression, obsessive-compulsive disorder, generalized anxiety disorder and social anxiety disorder. Rates of suicidality did not differ between genders.

The results from the regression analyses are summarized in Table 2. In both bivariate and multivariate analyses, having a diagnosis of BDD significantly increased odds of reporting suicidal ideation and suicidal behaviors. Similarly, MDE was associated with significantly increased odds of reporting suicidal ideation and suicidal behaviors, with little difference between bivariate and multivariate analyses. Table 2 also shows results from analyses where unipolar or bipolar depression were included in the models instead of the global MDE variable. Unipolar depression was associated with increased odds of suicidal ideation but not suicidal behaviors, whereas, bipolar depression was associated with increased odds of suicidal ideation and suicidal behaviors (although only marginally significant in the multivariate analyses). Including these variables in the models instead of MDE did not change the relationship between other disorders (e.g., BDD) and suicidality.

Discussion

The aim of the study was to examine whether mood, anxiety, and obsessive-compulsive spectrum disorders had unique (comorbidity-independent) associations with suicidality among patients in a partial hospital. The results showed that BDD and mood disorders had significant associations with suicidality, but anxiety disorders, OCD and PTSD were not uniquely related to suicidality in the sample.

Patients with BDD were significantly more likely than other patients to report suicidal behaviors and suicidal ideation. The strength of the relationship between BDD and suicidal behaviors was comparable to the relationship between MDE and suicidal behaviors. The relationship between BDD and suicidality remained virtually unchanged after adjusting for other disorders. These results are consistent with previous studies showing high rates of suicidal thoughts and behavior in patients with BDD (Phillips and Menard, 2006; Phillips, 2017), and extend the literature by showing that BDD in acute psychiatric settings has a unique association with suicidality that is not accounted for by symptoms of other internalizing disorders. Future research is warranted to better understand why BDD patients are vulnerable to suicidality (Witte et al., 2012).

The link between mood disorders and suicidality is well documented, but the strength of the relationship varies substantially depending on the population (e.g., greater in inpatient than outpatient settings; Bostwick and Pankratz, 2000). Here, we found that MDE in a partial hospital setting was associated with increased risk of both suicidal ideation and behaviors, even after controlling for other internalizing disorders. When examining unipolar and bipolar depression separately we found that unipolar depression predicted suicidal ideation, but not suicidal behaviors, and bipolar depression predicted suicidal ideation and marginally predicted suicidal behaviors.

In bivariate analyses, social anxiety disorder was associated with suicidal ideation (but not behavior); however, this association was not significant after adjusting for comorbid disorders. Other disorders assessed – OCD, PTSD and other anxiety disorders – did not have any association with suicidality in the sample. Overall, these findings could suggest that in acute psychiatric populations these diagnoses have limited incremental value in predicting suicidality above and beyond the elevated risk already associated with the population.

However, two caveats should be noted. First, a substantial minority of patients were excluded from the interviews and we do not know if they disproportionally had certain diagnoses. For example, patients with recent severe trauma may have been more likely than other patients to be excluded from the interviews. Second, even though our sample was recruited from a clinically severe population it remains possible that the average symptom severity of specific diagnoses was less than the severity in samples recruited from specific disorder populations (e.g., OCD; Angelakis et al., 2015). Future studies using comprehensive assessment of symptoms and severity is needed to fully understand the relationship between specific psychiatric disorders and suicidality in psychiatric settings.

Studies in general populations have often found that females are more likely than males to contemplate and attempt suicide, while males are more likely than females to die by suicide (Schrijvers et al., 2012). In our sample there were no gender differences in the rates of suicidal ideation or behaviors. This is generally in line with previous studies in clinical samples. For example, Beautrais et al. (1996) reported equal number of male and females in their sample of individuals hospitalized after a serious suicide attempt, and Brown et al. (2000) found no gender difference in the rates of completed suicides among psychiatric outpatients.

The current study had several limitations that need to be considered. First, because of the low base-rates of many of the disorders (e.g., BDD, bipolar depression), the sample size for some analyses was relatively small. Thus, replication in larger samples is warranted. Second, we examined cross-sectional relationships between diagnoses and suicidality. Even though we focused on suicidality in the past month, and it is likely that the psychiatric disorders preceded the suicidality in almost all cases, the temporal relationship between these variables needs to be established in a prospective study. Third, as mentioned above, a minority of patients who admitted to the program did not undergo the structured interviews due to logistic or clinical reasons. It is therefore possible that excluded patients differed from the study sample in important ways. For example, in some cases, patients were excluded because of behavioral problems or acute distress at the day of the interview, and these variables may disproportionally reflect certain diagnoses over others. Fourth, we did not examine symptom severity, functional impairment, or primary diagnoses, which may be important when considering associations between psychiatric disorders and suicidality. Fifth, the sample was relatively homogeneous with respect to ethnicity and race (primarily non-Hispanic and White/Caucasian) and it is not clear how well the findings generalize to other ethnicities, races or socioeconomic classes. Finally, we did not examine several disorders that are known to have strong associations with suicidality, and may have influenced the findings, including personality disorders and psychotic disorders. It is quite possible that other diagnoses not assessed in the study will show unique associations with suicidality in this population.

In conclusion, the findings suggest that MDE and BDD have unique relationships with suicidality in a partial hospital setting that is independent of other internalizing disorders. BDD is a common and often underrecognized disorder (Zimmerman and Mattia, 1998), and clinicians should be aware of elevated risk of suicidality in this population. Further research is needed to better understand the nature of the relationship between BDD and suicidality, and whether the results generalize to other clinical settings.