What is The Psychiatrist’s Role in Obesity and Bariatric Surgery?

Dr. Sanjeev Sockalingham is the psychiatrist in a multidisciplinary team working in Toronto Canada, and he reminded us that obesity is now recognised as a metabolic disease that has negative effects on all organ systems. Read more about weight gain and obesity in mental health conditions.

He noted that diet and exercise plans for our patients are frequently ineffective, partially because we tend to overestimate the weight loss benefits of exercise, which might be better seen as an accompaniment to good physical and mental health rather than a weight loss strategy (it is estimated that it takes a half marathon to “run-off” a Big Mac).

Furthermore, ghrelin (a hunger hormone) is elevated and the satiety hormone leptin is suppressed following weight loss, suggesting perhaps for evolutionary reasons our body tends to defend higher weight levels once we reach them. We also have no reliable and safe pharmacological agents.

Current indications for bariatric surgery are a BMI >40, or >35 with a weight loss responsive comorbidity. The gastric band has been progressively replaced by the sleeve, due to band slippage and chronic inflammation. Some Roux-en-Y gastric bypasses are still performed to add therapeutic malabsorption to food restriction, but with variation between individual treatment centres.

Funding is still broadly private, but health economic studies estimate a payback to the health system in 2-4 years. Almost all of the procedures can be performed laparoscopically, and often without the near-impossible need to lose 10kg of weight beforehand. Results for the gastric sleeve showed an average 11 point reduction in BMI for the first year and reduced all-cause mortality. The gastric bypass has the risk of a dumping syndrome and requires supplements of Vitamin D, calcium, Vitamin B12, iron, and copper indefinitely.

Psychiatrists can assist throughout the process, from anxiety about the assessment process and the decision to proceed to managing pre-morbid maladaptive eating behaviours.

While most patients gain improved body image afterwards, there may be a one-year “honeymoon” after which new eating or other psychopathology can present. This can include a preoccupation with weight gain leading to restriction, self-induced vomiting or excessive exercise. Excess skin folds may also be a focus and sometimes require further surgery, at times with fear or shame about needing a further procedure.

Interestingly alcohol overuse can emerge post-surgery, even if not evident before. This is, particularly after gastric bypass, due to more rapid absorption and intoxication. There may also be a later peak due to the re-emergence of unresolved psychological difficulties, perhaps in substitution of the addictive elements of eating onto alcohol.

For these reasons, alcohol use disorders are screened for before surgery, with a recommendation of six months of abstinence. Careful monitoring and early intervention for increasing use after the procedure is also required.

There is a slightly higher rate of suicide in patients who have completed bariatric surgery, compared to both normal and obese controls. While unclear, this may relate to reduced absorption of antidepressants with emergent symptoms or struggling to manage life after body shape change, despite whether pre-surgical expectations were met or not.

As rates of obesity increase, and sometimes in our patients due to our own intervention, we can play a valuable role in managing this condition. If diet and exercise are not working, bariatric surgery in its current form is a relatively safe and effective intervention, and we are well placed to manage its complex biopsychosocial challenges longitudinally with our patients.

The above is an abbreviated version of an article written for Mindcafe Issue 12, July 2015. It comprised recollections from an APA course on the above topic.

[Sockalingam et al, 2020].  [Vaishnav et al, 2022]

High Prevalence of Psychiatric Comorbidities:

• Up to 70% of bariatric surgery candidates have diagnosable psychiatric conditions, including depression, binge eating disorder, and anxiety, with significant pre-surgery suicidal ideation reported.
• Many candidates for bariatric surgery struggle with low self-esteem, sexual dysfunction, insomnia, cognitive issues, and relationship problems. These challenges are often exacerbated by perceived stigma and a history of mental health issues like childhood sexual abuse.
• These psychiatric comorbidities and psychosocial factors contribute to a significantly diminished health-related quality of life (HRQoL) among bariatric surgery candidates.

Postoperative Psychiatric Exacerbation:

• Initial reductions in psychiatric symptoms often follow bariatric surgery, but this “honeymoon period” can be followed by a resurgence of symptoms like depression and binge eating, which are associated with poorer weight loss outcomes.

Increased Risk of Self-Harm and Suicide:

• Post-bariatric surgery patients face higher risks of self-harm and suicide compared to the general population, emphasising the need for robust psychiatric support and intervention.

Increased Risk of Substance Use Disorders: 

• After bariatric surgery, there may be a new onset of substance use disorder (SUD), with a pooled incidence of 4.28% observed for new-onset SUDs. [Martinelli et al, 2024]. 
• Predisposing factors for SUD after bariatric surgery include mental health disorders, high BMI, and postoperative complications.
• There is a significant link between ADHD and addictive-like eating behaviours in bariatric surgery candidates [El Archi et al., 2021]. 
• Individuals experiencing insufficient weight loss show higher frequencies of lifetime binge eating disorder (BED) and comorbid BED-mood disorders compared to those with favourable post-surgical outcomes.
• They also scored higher on scales evaluating emotional dysregulation, a core symptom of ADHD in adults, highlighting the importance of the role of psychiatry in the management of post-bariatric surgery patients.
• Preventive actions are recommended for patients at high risk of new-onset SUD following bariatric surgery.

Critical Role of Preoperative Psychiatric Assessment:

• A referral to a psychiatrist should be considered to evaluate a patient’s psychological stability and readiness for surgery, influencing the approach to postoperative care.
• Tools like the Boston Interview and Bariatric Interprofessional Psychosocial Assessment Suitability Scale (BIPASS) can gauge a patient’s treatment engagement, strengths, and psychological stability before surgery. These assessments help in tailoring the psychiatric care needed post-surgery.

Monitoring Psychiatric Medications Post-Surgery:

• Changes in drug metabolism and absorption post-surgery necessitate careful monitoring of psychiatric medications
• SNRIs (except Duloxetine) may be less affected by malabsorption after bariatric surgery.
• Postoperative bariatric patients may experience vomiting due to complications or challenges in maintaining adequate hydration as they progress through their post-surgery diet. This can substantially affect their fluid intake and potentially elevate lithium levels.

Psychosocial Interventions:

• While varying in impact on weight loss, psychosocial interventions have shown benefits in reducing symptoms of eating psychopathology, anxiety, and depression.
• Psychological interventions, including cognitive behavioural therapy (CBT), behavioural interventions, and multi-modal comprehensive programs, enhance binge eating patterns, health-related quality of life (HRQoL), and weight loss, but these benefits typically last only in the short to medium term.

Timing of Interventions:

• Optimal psychiatric interventions are ideally delivered post-“honeymoon period” but before the re-emergence of problematic eating behaviors and weight regain.