Why is a pre-operative phycological assessment of a patient considering bariatric surgery necessary?

According to the South African Society for Surgery, Obesity, and metabolism (SASSO) as many as  50% or more of patients referred for Bariatric/Metabolic surgery are reported to have a psychiatric Axis I disorder, an Axis II personality disorder, or have doubtful motivation for surgery. 

Approximately half are taking psychotropic medications when they present for evaluation. Common diagnoses include somatization, social phobia, obsessive-compulsive disorder, substance abuse/dependence, binge eating disorder, night eating syndrome, post-traumatic stress disorder, generalized anxiety disorder, and depression. In the United States, 15% to 30% of patients with psychosocial difficulties are referred for additional treatment, and 0% to 10% are not recommended for surgery. 

Although consensus for a standardized protocol for the psychiatric and psychological evaluation of Bariatric/Metabolic surgical candidates is lacking, many centers use a structured interview. Examples include the Boston interview for gastric bypass, the structured clinical interview with the Weight and Lifestyle Inventory from the University of Pennsylvania, and guidelines from Montefiore Medical Center/Albert Einstein College of Medicine. 

Because many bariatric centers use a number of mental health professionals to conduct their assessments, a structured clinical interview allows the treatment team to identify key psychosocial areas that may need further evaluation. Psychological testing is often part of this assessment, and many clinicians use the Beck Depression Inventory or the Minnesota Multiphasic Personality Inventory. Key areas to identify include current depressive symptoms, personality disorders, trauma history, substance abuse, or purging. 

In general, the influence of psychological factors on long-term outcome in Bariatric/Metabolic surgical patients is not well understood. A 2005 review of the published literature examining the psychological evaluation of Bariatric/Metabolic candidates confirmed that the presence of binge-eating disorder, a personality disorder, or an untreated Axis I disorder, particularly a depressive disorder, warrants additional attention. 

These factors were found to be highly prevalent in pre-surgical patients and have been proposed to contribute to poor long-term outcomes. In a review of 29 studies that assessed possible psychosocial predictors of weight loss, serious psychiatric disorders that required inpatient hospitalization and personality disorders were found to predict suboptimal weight loss after surgery. 

Further research is needed to provide a better understanding of how an untreated psychiatric condition such as major depression can impact weight loss and other outcomes of Bariatric/Metabolic Surgery. 

Some Bariatric/Metabolic surgical candidates are denied surgery on the basis of their psychiatric status, and others have surgery postponed until their psychological difficulties have improved. 

A survey of 81 Bariatric/Metabolic surgery programs found that the most commonly ranked potential psychosocial contraindications for surgery were current illicit drug abuse, active uncontrolled symptoms of schizophrenia, severe mental retardation (IQ <50), heavy alcohol use, and lack of knowledge about surgery. 

Another area that should be assessed is the perception of the positive aspects of being overweight. Being overweight prevents some individuals from addressing painful issues. 

In our clinical experience, surgery and major weight loss can produce the sudden onset of symptoms of post-traumatic stress disorder in some survivors of sexual abuse or trauma. Even after these patients have successfully managed horrific memories for many years, substantial weight loss seems to trigger frequent flashbacks, daily intrusive memories, and nightmares. 

A history of childhood trauma is distressingly common in those considering Bariatric/Metabolic Surgery. Although no difference in weight loss was noted at 1-year follow-up, the sexual abuse survivors had higher levels of depression on the Beck Depression Inventory compared with those who had not been abused. 

Patients with a history of trauma; those who have experienced psychiatric difficulties when they lost weight in the past, and individuals who perceive being overweight as protective, warrant special attention, but should not necessarily be excluded from Bariatric/Metabolic Surgery. 

After a preoperative assessment, these patients should initiate mental health care to address these issues. Although a history of sexual abuse has reportedly been related to poor weight-loss outcomes after a low-energy diet program, weight-loss outcomes after Bariatric/Metabolic surgery have not differed significantly between sexual abuse survivors and those with no history of abuse. 

A history of psychological difficulties or the presence of a psychiatric disorder that is well managed is not a contraindication to Bariatric/Metabolic Surgery. A history of treatment for mental illness or substance abuse was predictive of acceptable weight-loss outcomes at a 2-year follow-up in patients who had undergone Bariatric/Metabolic Surgery. 

It is recommended to delay surgery when:

A patient presents with current acute or inadequately treated mental illness. This includes patients with severe depressive disorders, anxiety disorders, and bipolar disorder

Patients with severe binge eating disorder

Current significant life stressors

Lack of social support to cope with the post-surgical transition

Poor understanding or appreciation of potential risks and requirements for surgery

These patients can be referred for further psychiatric treatment and then re-evaluated after 12 months.

Source Credit: South African Society for Surgery, Obesity, and metabolism (SASSO)

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