Bariatric surgery is an increasingly vital intervention used to treat obesity, a globally rising health concern. While bariatric surgery offers significant benefits for physical health, it also introduces potential mental health risks. Patients may experience dissatisfaction due to unmet weight loss expectations, which can exacerbate psychological distress. Psychiatric complications following bariatric surgery may include depression, anxiety disorders, eating disorders, body image disturbances, psychotic syndromes, and an increased risk of suicide.
This article aims to comprehensively review the psychiatric complications linked to bariatric surgery, covering assessment, differential diagnosis, and management strategies for these challenges. It also highlights the crucial role of an interprofessional healthcare team in treating patients undergoing bariatric surgery, thereby enhancing patient outcomes through comprehensive mental healthcare.
Types of Bariatric Procedures
Bariatric surgery encompasses a variety of procedures, broadly categorized into restrictive, combined restrictive, and malabsorptive types.
Restrictive Procedures
Restrictive procedures primarily limit food intake by reducing the size of the stomach. These include:
- Laparoscopic Adjustable Gastric Banding (LAGB): This procedure involves fitting an adjustable band to create a proximal gastric pouch of about 30 mL, limiting food intake and inducing early satiety.
- Laparoscopic Sleeve Gastrectomy (SG): This procedure entails removing a portion of the stomach and stapling the remainder to form a "sleeve" with a capacity of approximately 60 to 120 mL.
Combined Restrictive and Malabsorptive Procedures
These procedures combine restriction of food intake with a degree of malabsorption, altering how the body absorbs nutrients. These include:
Read also: Reducing Muscle Soreness After Massage
- Roux-en-Y Gastric Bypass (RYGB): This procedure involves constructing an approximately 30 mL proximal gastric pouch by stapling and dividing the stomach. The pouch is then connected to a segment of the jejunum for drainage.
- Biliopancreatic Diversion (BPD): This procedure removes a small section of the stomach and creates alternative routes to the small intestine. A BPD with a duodenal switch incorporates a vertical sleeve gastrectomy and a duodenoenterostomy.
Psychiatric Complications
An important consideration for both patients and healthcare professionals is the potential for psychiatric complications arising from bariatric surgery. Psychiatric sequelae may vary depending on the type of procedure undergone. For instance, a cohort study conducted in Taiwan tracking patients over 12 years discovered a 1.5-fold heightened risk for major depressive disorders (MDDs) after malabsorptive procedures compared to restrictive procedures.
Preoperative Psychiatric Conditions
The most likely risk factor for developing psychiatric complications following bariatric surgery is the presence of one or more psychiatric disorders before the operation. Common psychiatric conditions observed in bariatric surgery candidates include depression, anxiety, substance use disorders, and binge-eating disorder. Untreated eating disorders (most concerning being anorexia nervosa or bulimia nervosa), psychotic symptoms, severe depression, or active substance use disorders are considered relative contraindications for bariatric surgery.
Postoperative Psychiatric Conditions
Bariatric surgery constitutes a significant, life-altering event that has the potential to spur mental illness de novo. The likely explanations include drastic dietary changes in the postoperative period, including consuming smaller portions and adjusting to new food types. Behavioral restrictions, such as eating slowly or only during certain times (while avoiding late-night eating), also contribute to this transition. In addition, complications such as dumping syndrome may induce anxiety, while excess skin resulting from significant weight loss has the potential to alter body image perception, potentially leading to distress.
Postoperative addiction transfer emerges as a significant psychiatric complication of bariatric surgery. Patients who previously relied on eating as a maladaptive coping mechanism for underlying mental illness and distress may face challenges when this option is limited post-surgery due to physical changes reducing stomach capacity. Consequently, they may replace their prior addictive eating habits with new or exacerbated substance use. Substance use in the postoperative period is prevalent, with alcohol being the most commonly reported substance used. Particularly alarming among these changes is the heightened risk of suicide in the postoperative period, a phenomenon consistently observed across multiple studies. This phenomenon likely arises from a combination of factors, including postoperative dietary and behavioral constraints, along with dissatisfaction regarding weight loss or harboring unrealistic expectations that bariatric surgery will resolve many of the patients' preexisting struggles.
Nutritional Deficiencies and Mental Health
Preoperative psychiatric comorbidities have the potential to significantly influence outcomes post-bariatric surgery. Various micronutrient deficiencies following bariatric surgery have been reported due to food absorption changes. Although all types of procedures were associated with deficiencies, malabsorptive or combined types increased the risk of vitamin B12 deficiency by over 3-fold compared to restrictive procedures, owing to reduced parietal cells and decreased production of intrinsic factors. In addition, mineral deficiencies such as iron and calcium are more prevalent with combined-type procedures, as the main sites of absorption for these minerals occur in the duodenum and proximal jejunum, which are bypassed with this procedure. As a result, a study revealed that anemia occurred in nearly half of all patients undergoing RYGB, affecting approximately 17% of those undergoing restrictive-type procedures. The effect of vitamin D absorption varies depending on the type of surgery undergone. According to a recent review, sleeve gastrectomy showed no deficiencies in vitamin D absorption at multiple postoperative time points (3, 6, and 12 months). Additionally, compared to preoperative states, the risk of vitamin D deficiency decreased following sleeve gastrectomy. Alterations in the gut microbiome can impact mood and behavior by influencing gut peptides such as ghrelin, glucagon-like peptide 1, peptide YY, and cholecystokinin.
Read also: Achieve Weight Loss with CrossFit
Epidemiology of Psychiatric Conditions in Bariatric Surgery
Individuals eligible for bariatric surgery, as well as those who undergo the procedure, often experience depression, anxiety, and specific eating disorders, such as binge eating, with prevalence rates exceeding 15%. Although the occurrence of other mental health conditions like psychoses is relatively rare, reported prevalence rates, particularly for depression and binge eating disorder, exhibit considerable variation. Studies conducted within veteran populations indicate a higher prevalence of comorbid conditions, particularly posttraumatic stress disorder, compared to other groups.
Studies conducted within veteran populations have indicated that rates of depression, anxiety, and eating disorders decrease at various reference points following bariatric surgery. However, other studies have shown that a significant proportion of patients develop "loss of control" eating habits within 2 years post-surgery. This term is defined as difficulty controlling eating behaviors despite not meeting the formal criteria for a binge-eating disorder. Bariatric surgery has also been found to be associated with an increased risk for self-harm and suicide, as well as alcohol use disorders in the postoperative period. In a recent study, the relative risk for suicide was found to be 64% higher in the surgical cohort compared to the nonsurgical cohort. Additional studies have supported these findings, indicating increased alcohol use following bariatric surgery. One recent study reported alcohol use rates ranging from approximately 7.6% to 11.8% among patients who underwent bariatric surgery.
Pathophysiology of Psychiatric Complications
The pathophysiology of psychiatric complications following bariatric surgery appears to involve a complex interplay of physiological, psychological, and nutritional factors. Surgically induced modifications to the gastrointestinal tract can potentially disrupt the gut microbiome and alter normal absorption processes, which may affect the pharmacokinetics of alcohol, other substances, and various medications. Such changes could conceivably lead to higher plasma concentrations of these substances, potentially amplifying their psychological effects and contributing to the onset or worsening of psychiatric symptoms.
Nutritional deficiencies that often follow bariatric surgery, such as deficits in vitamins D and B12, iron, and thiamine, may significantly contribute to the development of psychiatric issues. These deficiencies can lead to neurological symptoms that mimic or exacerbate mental health conditions. Furthermore, alterations in the gut-brain axis, involving hormonal and neuronal communication pathways, may influence mental health outcomes. Hypothetically, changes in gut-derived hormones, such as ghrelin and peptide YY, can impact mood regulation and behavior, possibly exacerbating conditions such as depression and anxiety. Moreover, altered absorption of nutrients and medications may also compromise the effectiveness of prescribed psychiatric drugs, potentially resulting in suboptimal control over preexisting mental health conditions.
Additionally, the presence of preexisting psychiatric disorders such as MDD or anxiety can significantly influence the likelihood and severity of postsurgical psychiatric complications. Psychological stressors associated with adjustments to postoperative lifestyleâsuch as notable changes in body image and restrictive eating patternsâmay further complicate the psychiatric landscape. The inability to use food as a coping mechanism, often referred to as "emotional eating," may leave some patients with fewer strategies for managing stress, potentially leading to an increase in compulsive behaviors or substance use. These complex pathways highlight the necessity for comprehensive mental health assessments and strong nutritional support for patients undergoing bariatric surgery.
Read also: Transformations with Ozempic
Pre- and Post-Surgical Assessment
Candidates for bariatric surgery must undergo a comprehensive psychiatric evaluation, which helps establish a baseline psychiatric profile and facilitates ongoing monitoring of any postsurgical psychiatric symptom changes. A patient's preassessment social history should include detailed information relevant to the patient's current life situation and capacity to adhere to surgical aftercare, which significantly influences postoperative success. During follow-up, both medical and psychiatric symptoms must be thoroughly evaluated. The clinician's assessment should proceed as follows:
- Signs of MDD or other mood disorders should be identified as outlined in the DSM-5. Symptoms such as anhedonia, dysphoria, fatigue, appetite changes, guilt, and psychomotor alterations must be consistently present for a minimum of 2 weeks.
- Eating disorder behaviors (eg, binge eating, purging, and undue dietary restrictions) should be carefully monitored.
- Weight changes should be tracked over time to verify healthy progress.
- The mental state of the patient should be evaluated for any new or worsening symptoms such as delusions, hallucinations, or paranoia.
- Substance use should be reviewed carefully, particularly for signs of alcohol use disorder, which is a common complication after bariatric surgery.
This structured approach to pre- and postsurgical assessments ensures a holistic evaluation of the patient's readiness and ongoing response to bariatric surgery, identifying any psychiatric barriers to successful outcomes.
Screening Tools and Evaluation Protocols
Given the elevated suicide risk among postoperative bariatric surgery patients, it is prudent to implement a systematic screening program for depression and suicidal ideation. Such a program can be effectively integrated into routine follow-up consultations. The Patient Health Questionnaire (PHQ-9) is a recommended tool for this purpose. This brief self-administered survey comprises 9 items, each scored from 0 to 3, resulting in a potential total score ranging from 0 to 27. The PHQ-9 effectively targets vital symptoms of depression, such as anhedonia, dysphoria, fatigue, appetite irregularities, feelings of guilt, lack of motivation, difficulty concentrating, changes in motor activity (such as agitation and retardation), and thoughts of suicide, by assigning scores based on the frequency of these symptoms over the assessment period.
A score greater than 10 on the assessment indicates at least moderate depression, warranting consideration for counseling and pharmacotherapy. A score exceeding 15 indicates the necessity for active pharmacotherapy and psychotherapy treatment. Finally, a score surpassing 20 indicates an immediate need for pharmacotherapy and an expedited referral to a psychiatrist, psychologist, or therapist for collaborative treatment. Furthermore, any positive response to question 9, which specifically inquires about suicidal thoughts, should prompt an immediate risk assessment for the threat of imminent danger to the patient.
Other psychometric tools, including the Columbia Suicide Scale, can be used to assess suicide risks further. If necessary, immediate consultation with a psychiatrist should be obtained and acute hospitalization pursued. Alongside screening for depression, it is imperative to thoroughly investigate the patient's eating habits, with particular attention to potential eating disordered behaviors, and closely monitor their weight trends.
The patient should also be screened for potential substance use after surgery. One useful psychometric tool for assessing substance use is the Screening, Brief Intervention, and Referral for Treatment (SBIRT) tool. In patients presenting with anxiety symptoms, a thorough history and physical examination are necessary to exclude organic diseases, including dumping syndrome. Cardiac causes of palpitations should also be explored, considering the likelihood of electrolyte imbalances in the postoperative period.
Eating Disorders and Problematic Eating Behaviors
According to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, BED is defined as eating an unusually large amount of food in a short period of time (about 2 hours) and must be accompanied by a sense of loss of control (LOC) over eating (i.e., feeling that one cannot stop eating or control the amount of food eaten). To meet the minimum diagnostic criteria for mild BED, a patient must engage in binge eating at least once per week for the past 3 months, and the binge eating must cause marked distress. BED is the most common eating disorder among bariatric surgery candidates.
Rates of BED have varied considerably across studies due to methodological differences, including over-reliance on self-report instruments and retrospective accounts versus structured clinical assessments. In addition, there is currently no standardized approach to conducting the pre-surgical psychological interview, which can lead to biased estimates of BED and psychopathology. Ideally, clinicians and researchers would evaluate current eating and other forms of psychopathology using gold standard approaches, such as the Eating Disorders Examination (EDE), a structured clinical interview that assesses dietary restraint, as well as eating, weight, and shape concerns, and has been adapted for use with bariatric surgery patients (The EDE-Bariatric Surgery Version; EDE-BSV) and the Structured Clinical Interview (SCID-5) for DSM-5 disorders, respectively. The EDE is lengthy to administer and requires training, and so it is not widely used but does have a validated questionnaire form, the EDEQ, that can be used instead.
Another area of interest in the past several years has been to determine whether pre-surgical binge eating or BED are related to suboptimal weight loss outcomes after bariatric surgery. Numerous studies have been conducted, but the majority do not support a relationship, and only a few support that BED is related to poorer weight loss outcomes. For this reason, binge eating and BED is not considered to be a contraindication for bariatric surgery.
Picking and nibbling (P&N) is defined as unplanned and repetitious eating in between meals and snacks, where it is unknown how much food will be eaten at the outset. The term is often used interchangeably with grazing. P&N/grazing are prevalent among patients with eating disorders, including anorexia nervosa (AN), bulimia nervosa (BN), and BED, and those pursuing bariatric surgery but do not appear to be associated with other eating disordered behaviors or psychopathology. This may be because LOC eating is not included in the definition of P&N. To date, it is unclear whether or not P&N is a normative, disordered, or maladaptive eating behavior, and this is even less clear among bariatric surgery candidates, who may engage in P&N to restrict eating in an attempt to lose weight. However, there is evidence that those who engage in grazing pre-surgery may be more likely to continue this behavior after surgery, which we will later discuss, has a deleterious effect on weight loss.
Approximately 17% of bariatric surgery candidates have NES, according to recent estimates, although lower and higher rates have been reported. The Night Eating Questionnaire (NEQ), the most widely used, validated, self-report measure of night eating, can be used in conjunction with a diagnostic interview and a 24-hour food recall to assess NES in bariatric patients. However, it should be noted that the presence of pre-surgical NES is not a contraindication to surgery.
Pre-surgical eating disordered behaviors, particularly binge eating, have been associated with significant psychopathology, including higher rates of depression, mood disorders, less perceived interpersonal support, alcohol use, and lower HRQoL, defined as the impact of health on an individualâs functioning, including, but not limited to, physical and mental health domains.
Post-Surgical Eating Behaviors and Weight Loss
In bariatric surgery research, weight loss has usually been utilized as the primary outcome, with resolution of medical comorbidities also emphasized; eating behaviors have received less attention. However, several recent studies show that problematic eating contributes to suboptimal weight loss trajectories and weight regain. A smaller percentage of patients may also develop post-surgical eating disorders such as AN. Therefore, it is critical to identify postoperative patients at risk for LOC eating and to monitor their eating behaviors and weight loss progress using the EDE-BSV, for example, which more accurately assesses eating disordered behaviors after bariatric surgery. Patients identified as having LOC eating and comorbid psychopathology may then benefit from a targeted intervention that addresses both.
Picking and nibbling (P&N)/grazing is the most frequent problematic eating behavior after surgery, affecting about 30% of bariatric patients. Some patients develop a new onset of P&N post-surgery; although, a risk factor is preoperative LOC eating. The difficulty with differentiating P&N from normative eating behavior is that patients are required to eat several small meals throughout the day after surgery.
Currently, there is limited research on NES after bariatric surgery. However, a recent review noted that it occurs less frequently post-surgery. One study found a decrease in night eating from pre- to post-surgery at one year follow-up (17.1% to 7.8%), but this study was limited to patients having laparoscopic adjustable gastric banding (LAGB). Another study suggested that postoperative night eating symptoms improved among patients who had preoperative depressed mood versus those without it, but the relationship between mood and NES is complex; other factors including sleep may also play a role. For example, sleep problems and depressive symptoms typically improve for most patients in the short-term following surgery. Thus, while positive changes in HRQoL and eating are typically observed in the early postoperative period, there appears to be more variability in outcomes in the later postoperative years, which in some studies, has been dependent on the type of surgery and related to the amount of weight lost.
A limitation of the literature on psychosocial outcomes after surgery is that, with the exception of a few studies, the data have been limited to studies with outcomes at 2â3 years post-surgery.
Treatment Strategies
A critical component of the pre-surgical psychological evaluation is to identify patients with significant untreated psychopathology including BED. An appropriate intervention should be considered (i.e., referral for psychotherapy and/or psychotropic medication), but generally such interventions should be deferred until after surgery. For example, non-bariatric patients meeting DSM-5 criteria for BED would typically be referred for cognitive-behavioral therapy (CBT), the first-line, evidence-based treatment for BED, which focuses on normalization of eating patterns, reduction of binge eating, and improvement in mood symptoms rather than addressing weight loss, which rarely results from such an intervention. Some bariatric programs have developed brief, group CBT protocols to treat binge eating prior to surgery and found that patients with BED who completed the group, improved on binge eating scores such that they no longer met criteria for BED before surgery. Antidepressants or stimulant medications can also be used in lieu of or as an adjunct to psychotherapy. However, BED should not be regarded as a contraindication to bariatric surgery, since some patients experience a remission of BED with surgery and progress normally.
It has been well-documented that problematic eating behaviors pose the greatest threat to meaningful and sustained weight loss, and that a new onset or recurrence of such behaviors (i.e., LOC eating) can occur within 12 months or earlier after surgery, which can result in less weight loss at long term follow-up. Treatment for post-operative eating disorders is, again, usually CBT. However, inpatient or day treatment may be necessary for those who develop AN or BN. Medications are typically used for depression and adjunctive for BN and BED.