The issue of patient’s mental health before undertaking bariatric surgery has come to the center of discussion in recent years. Although the benefit of gastroplasty surgeries is life-saving to most patients with excessive weight, new conditions emerge after surgical procedures.  Nutritional problems, excessive skinfold due to rapid weight loss, and the onset of new forms of psychopathology are among several medical discomforts that require lifelong follow-up [1,2].  While some patients would engage in “loss of control eating”, impeding the weight control [3], others would start binge drinking, replacing previous compulsive behaviors [4,5]. Also, maniac or hypomanic reactions are commonly observed among those with previous history of bipolar disorder [6].  Suicidality after surgery could develop after years of follow-up [7].  Possibly, all these unfavorable events could be preventable if the patient were assessed during the pre-surgical period.  Careful assessment of previous treatment for mental health and patients’ characteristics is pivotal for safe planning of the surgical procedure.  Before and after surgery, at-risk candidates should receive adequate management than betting on hazards of an adverse and unpredictable outcome.

Our cumulative knowledge on the course of patients undertaking bariatric surgery is still scant.  Several methodological shortcomings have impeded its comprehension.  First, it is hard to recruit a representative sample of patients with severe obesity.  Most studies report single-center data with a small sample of participants.  Lack of control group is more a rule than an exception.  Longitudinal surveys of a large sample are rare. The existing ones present several limitations, with emphasis on medical diseases than mental health [8,9]. Improving the design of the survey could recruit a sample whose findings are generalizable to other people with similar BMI. Second, most assessments of psychopathology are non-systematic and has relied on patients’ self-report.  Although guidelines recommend a systematic assessment with validated tools, this is not a widespread practice across centers [10]. Thus, the comparability of the results is limited because studies use different questionnaires.  Frequently, these short questionnaires can only cover a small portion of a patient’s mental problems.  Self-reported answers from eager patients wishing a surgical weight loss are not reliable.  Therefore, it is recommended that improved methodologies closely investigate the characteristics of patients with obesity.  A personal interview with valid assessment tools of mental health, for example, the Structured Clinical Interview for Disorders of DSM (SCID) [11] is one of the most adopted strategies.    

We summarize below our experience of assessing a bariatric sample of candidates for surgery from a university-based bariatric center.  Following, we discuss the implications of mental disorders in bariatric surgery.

This is a commentary on the article “Gender-related patterns of psychiatric disorder clustering among bariatric surgery candidates: A latent class analysis”, which has synthesized the results of a series of analyses in a sample of patients with obesity waiting for the surgical procedure [12]. Previous studies about the patterns of psychiatric comorbidity in patients with obesity during the preoperative period were inconclusive, though it has indicated an excess of mental disorders when compared to the general population [13]. The reported rates greatly vary by sampling issues and the method of the diagnostic evaluation, making it difficult to obtain a representative sample of patients with surgical indication and reliable psychiatric diagnoses.

The primary data of our study were collected at a university bariatric center, where participants were recruited from the institutional list of patients awaiting surgery. All eligible patients were face-to-face and consecutively interviewed through the SCID interview [14].

The results of 393 patients indicated that 80.1% of candidates for bariatric surgery presented at least one lifetime psychiatric disorder and 53% at least one disorder at the time of interview. Among those with any psychiatric disorder, about 19 % presented one single disorder, and over half of patients (61.8 %) presented two or more lifetime disorders. Regarding current disorders, about 27% of the patients presented one single disorder and 31% two or more disorders at the time of assessment.

Mood disorders were the most common lifetime disorder, but not at the time of assessment. Conversely, anxiety disorders were frequent in both lifetime and the time of interview. These results suggested psychiatric morbidities are chronically persistent among candidates for bariatric surgery. Unsurprisingly, anxiety disorders were the most persistent group of disorders, which prevalence ratio between lifetime and the current diagnosis was 84.7% [15].

The pattern of frequency, comorbidity, and persistence of psychiatric disorder varies conspicuously by gender. We investigated how the pattern of comorbidity clustered in the group of females and males. We used the method of latent class analysis, also known as a model of finite mixture, a multivariate technique for extracting a homogeneous group of patients with obesity who share common psychopathologies. The best-fitting solution for women clusters was: class 1, which was labeled “oligosymptomatic” because 42% of women in this class have presented low or null probabilities of psychiatric disorders; class 2, the “bipolar comorbidities”, characterized by high rates of comorbid bipolar and anxiety disorders (33%); and class 3, or “anxiety/depression”, where high rates of comorbid anxiety and depressive disorders co-occur (25%). Similar clustering of “oligosymptomatic”, “bipolar comorbidities” and “anxiety/depression” classes were observed among men, respectively in 40%, 47% e 13% [12].

Key findings from this investigation were (1) most of the patients were symptomatic and presented comorbid patterns of psychopathology before undertaking surgery, where around 40% of the sample presented few psychiatric symptoms; (2) 33% to 47% were anxious bipolar patients; and (3) 13% to 25% were admixed anxiety and depression.  Regarding gender, a significant difference stood out, almost half of the men seeking surgery was a bipolar patient with some comorbidities (mainly anxiety) and women presented two-fold more anxiety and depression than men.

Should surgeons care about psychiatric disorders among patients with obesity?

Consistent observations of the high frequency of mental disorders among patients with severe obesity are undeniable in bariatric surgery. Two findings of our investigation merit further highlight the effect of gender over psychiatric manifestations and the psychopathological presentation of bipolar disorders among patients with obesity.

One of the neglected points in the field of bariatric surgery is the fact that co-occurring obesity and psychopathology differ according to gender.  Historical social pressure on the standards of an ideal body has shaped women’s concern about their weight. However, apart from the stigma of obesity, patients at level III of obesity (BMI ≥ 40 kg/m2) must deal with the adverse consequences of excessive weight on their physical health, mobility, mental health, and functionality.

Traditionally, the health-seeking behavior of men and women is different, even so, when looking for surgery. The sex ratio of men to women in our sample of the waiting list was around 1:3. There is a consensus in well-conducted international studies that women present two or three-fold more psychiatric morbidities than men [16].  However, there was no significant difference between lifetime and the current diagnosis of mental disorders for high-BMI females and males who were candidates for surgery [14].  The willingness to lose weight and treatment-seeking behavior of women with obesity could have included a group with few psychopathologies to surgery. An alternative explanation for the lack of gender effect on the frequency of mental disorders in bariatric samples can be regarded as an effect of selection bias. In other words, although women used to present more mental disorders than men, male participants seeking bariatric surgery in our sample presented higher BMI and were more impaired [12].

The state-of-art analytical technique of latent class analysis has confirmed the psychopathological similarity between women and men with severe obesity.  Both genders presented comparable patterns of psychiatric clustering. This groundbreaking method of separating individuals with analogous psychopathology into homogeneous clusters was applied for the first time in patients with obesity. In comparison with the "oligosymptomatic" class, the likelihood of higher BMI was observed among "bipolar" men and poorer work attainment among men with "anxiety/depression". Also, substance use disorders were prominent among "bipolar" men.

The second point to consider refers to the effect of the previous psychopathology before undertaking surgery.  This issue has a huge implication for the surgical outcome and has not yet been properly addressed. Previously, most researches have focused on the prognostic effect of a single disorder on the outcome of surgical procedures.  For example, it is believed that binge eating disorders were the most important predictor of further surgical success [17].  However, depressive and anxiety disorders have proved to be pervasive and persistent in this type of patient.  Therefore, the pattern of comorbidity should be considered, as far as almost two-third of symptomatic participants presented two or more concurrent psychiatric diagnoses.  Binge eating disorders appear as common psychopathology, but not the most frequent disorder.

Possibly, the severity of multiple disorders also determines the poor surgical outcome.  Bipolar disorders are typically associated with several disorders such as anxiety, depression, alcohol and substance use, and eating disorders.  Considering that men presented higher BMI and more diagnosis of bipolar disorders than women, practitioners should bear this in mind when indicating a surgery for those treatment-seeking individuals.   As consequence, systematic investigation of bipolar symptoms among patients, such as the symptom of hyperactivity, talkativeness, exuberance, and blustered behavior could indicate the probability of a hidden bipolar disorder.  Many of these symptoms can be unleashed after a surgical procedure.

In conclusion, evaluation and treatment should be planned in the light of the above observations to account for the features of men and women. Gender-sensitive approaches should be applied to each patient. These differences in the frequency patterns of psychiatric disorders in men and women still need to be explored and better understood. The methods of assessment, psychometric measurement with validated tools must continue to govern scientific studies. Future directions in the field include recruiting patients with obesity from multiple centers and following-up operated patients in the post-surgical period.  Liaison service with the close participation of mental health experts is increasingly recommended in bariatric services.

The authors declare no conflicts of interest.

None.

Both authors (YPW and LSDG) have equally contributed to the article’s conception, intellectual argumentation, and wrote the first draft.  Authors also agreed on its critical intellectual content and the decision of publication, as far as both have contributed sufficiently to take public responsibility for its opinion.