Psychiatric disorders, quality of life and effect of preoperative counselling in patients who undergo bariatric surgery

Background: Bariatric surgery is increasingly recommended as the treatment of choice for patients with severe obesity (BMI >40 kg/m2 or BMI >35 kg/m2 and a serious comorbid somatic condition). Surgical success, which includes the patients’ ability to achieve sustained weight loss and subjective well-being, is dependent on psychological and behavioural factors. Psychiatric assessment and support prior to and after surgery are assumed to be beneficial for all patients undergoing surgery. Factors related to participation in such comprehensive treatment programmes, the necessary design elements of such comprehensive treatment programmes, and the relationship between participation in adjuvant treatment and weight loss and adherence to treatment guidelines are largely unknown. Further, little is known about the association between postoperative psychiatric comorbidity and weight loss and quality of life outcome. Objectives: The objectives in this thesis were to assess prevalence rates of comorbid psychiatric disorders prior to and one year after bariatric surgery and to compare prevalence rates of preoperative comorbid psychiatric disorders between patients willing to participate in counselling groups and patients unwilling to participate in such groups. The effects of preoperative psychological counselling on weight loss and adherence to guidelines for eating habits and physical exercise one year after surgery were examined. Finally, the association between psychiatric disorders and quality of life at follow-up one year after surgery were assessed. Methods: A total of 169 patients with obesity were screened for participation in the study. They were all referred from general practitioners (GPs) for gastrobariatric surgery at the Department of Surgery at Haugesund Hospital, Norway. Of these, 150 patients had psychiatric assessment and 144 were invited to participate in preoperative and postoperative counselling groups. Patients were interviewed using Mini International Neuropsychiatric Interview (M.I.N.I.) and Structured Clinical Interview (SCID-II) at assessment prior to and one year after surgery. The participants completed self-report questionnaires on depression (BDI), anxiety (BAI), shame (ISS), and quality of life (SF-36) at preoperative assessment, three months after surgery, and one year after surgery. They also accounted for compliance with guidelines of eating habits and exercise at follow-up three months and one year after surgery. Results: The overall prevalence of current psychiatric disorders was 49% among patients on a waiting list for bariatric surgery. Sixteen patients (18%) fulfilled the diagnostic criteria for a psychiatric disorder at one year follow-up. Significant predictors for postoperative psychiatric disorder were preoperative psychiatric disorder and preoperative level of shame. Patients who were unwilling to participate in counselling groups had significantly higher prevalence of preoperative Social Phobia and Avoidant Personality Disorder than patients who agreed to participate. At follow-up one year after surgery, there were no differences regarding treatment adherence (eating habits and physical exercise) and weight loss in patients who participated in preoperative counselling groups compared to patients who did not participate in such groups. In the entire study sample, significant improvement in HRQoL was found in seven of the eight SF36 subscales from preoperative assessment to follow-up one year after surgery. However, in patients with postoperative psychiatric disorders, only a trend toward improvement could be detected in several of the subscales measuring HRQoL, and they still had impaired HRQoL one year after surgery compared to the population norm. Conclusion: Psychiatric disorders are prevalent among candidates for bariatric surgery. The presence of Social Phobia and Avoidant Personality Disorder influence the willingness to participate in preoperative counselling groups. At one year followup after surgery, we found no differences regarding weight loss, eating habits, or physical activity between patients who participated in preoperative counselling and patients that did not participate in such counselling. Prevalence of psychiatric disorders was significantly lower one year after bariatric surgery compared to prevalence rates at preoperative assessment. Level of shame at preoperative assessment was associated with maintenance of psychiatric problems. Compared to the population norm, patients with preoperative, but without postoperative comorbid psychiatric disorders, had impaired HRQoL on only two of the subscales measuring HRQoL one year after surgery. However, HRQoL in patients with postoperative psychiatric disorders did not reach the level of the general population, and compared to the population norm, they had impaired quality of life in all subscales measuring HRQoL one year after surgery