The present study examined the relationship of psychiatric disorders to weight outcomes at six months after Roux-en-Y gastric bypass. All analyses adjusted for initial weight parameters, age, sex, and race. Results indicate that patients with at least one lifetime Axis I clinical disorder prior to surgery exhibited poorer weight outcomes afterward. Specifically, mood and anxiety, but not substance or eating disorders, accounted for a modest, but significant amount of the variability in short-term outcomes. Although lifetime Axis I disorder had prognostic significance, whether or not there was a current episode within the last month was not independently predictive of short-term weight outcomes in this study.
The strengths of the current study include assessment of a broad range of Axis I and II psychiatric disorders with standardized assessment interviews confidentially administered by trained interviewers prior to surgery. Because analyses were restricted to short-term outcomes among patients who underwent gastric bypass, study results do not address the broader clinical question of identifying patients whose psychiatric status would contraindicate surgery. Nonetheless, this investigation does have some direct clinical implications. Results clearly support monitoring individuals who have ever had an Axis I disorder prior to surgery for sub-optimal weight loss afterward. Close surveillance of patients with current or past disorders may help in identifying patients who could benefit from early adjunctive interventions that target potential mediators of poor outcome. Patients with mood and anxiety disorders may be vulnerable to developing inappropriate eating, restricted activity, or other behaviors that affect compliance to the post-surgical regimen. Interventions targeting eating, activity or compliance may help patients achieve optimal postoperative outcomes.
This study also has some limitations. First, a majority of the sample met lifetime diagnostic criteria for an Axis I clinical disorder. However, only a minority of the sample met diagnostic criteria for a current Axis I clinical disorder or Axis II personality disorder at the time of preoperative evaluation. Therefore, it remains possible that a failure to detect a relationship between current Axis I disorder and Axis II disorder to short-term outcomes is due to limited statistical power. Accordingly, larger samples may be required to examine the relationship of mental health to outcomes more completely. Next, although analyses adjusted for weight-related parameters as well as patient age, sex and race, other factors we have not evaluated may account for some of the variability in short-term outcome, including surgical parameters such as length of Roux limb or anastomotic type. Finally, the study sample was comprised of predominantly middle-aged white females who underwent Roux-en-Y gastric bypass surgery. Therefore, results are most relevant to individuals fitting this demographic profile, and generalizability to other sub-groups of weight loss surgery patients may be limited.
As weight loss generally continues for 18 to 24 months after gastric bypass,27
a greater duration of follow-up is needed to evaluate predictors of longer-term weight control. Furthermore, predictors of longer-term weight control may differ from predictors of short-term weight outcomes. Indeed, a recent review of the literature suggests that those with clinically significant binge eating prior to surgery may be more likely to have binge eating problems after surgery, and if they do, have poorer longer-term weight outcomes.28
Thus, we continue to follow all patients prospectively to examine the impact of psychopathology on longer-term postoperative outcomes, and to evaluate the impact of surgery on mental health.
Future hypothesis-driven studies with larger samples, or inclusion of high-risk subgroups, may allow investigators to explore the impact of a broader range of surgical, biological, behavioral and psychosocial factors on postoperative weight control. Factors of interest may include a focus on aberrant eating patterns such as binge eating and night eating. Although Night Eating Syndrome (NES) is not a DSM-IV Axis I disorder, it has been associated with excess weight among psychiatric outpatients29
and has been associated with less weight loss in outpatient behavioral treatments.30
Moreover, the impact of factors of interest may vary over time as patients advance from initial weight loss toward longer-term weight stabilization. In summary, findings of the present study are important in documenting that patients who have ever had an Axis I mood or anxiety disorder exhibit poorer weight outcomes 6 months after gastric bypass than do those who have not had these disorders. Further examination of the relationships between mental health and bariatric surgery outcomes may inform the multidisciplinary treatment of individuals with severe obesity.