Table 3: Effects of psychiatric disorders on weight loss outcome.

Author and Publication year	Country	Study features	N Participants	Mean age	Sex	Other features of the study	Surgery/setting	Instruments	Results
White et al. 2015 [44]	New Haven, USA	Prospective, longitudinal study	357			To examine the prognostic significance of depressive symptoms in bariatric surgery patients over 6- 12- 24-months of follow up.	RYGB	Beck Depression Inventory	Depressive symptoms characterized 45 % of patients prior to surgery, and 12 % at 6-month follow-up, 13 % at 12-month follow-up, and 18 % at 24-month follow-up. Preoperative depressive symptoms did not predict postoperative weight outcomes. Postsurgery depressive symptoms were predictive of weight loss outcomes.
Steinmann WC et al. 2011 [92]	Columbia USA	Retrospective study				Comparison of patient underwent to RYGB: bipolar disorder group, other psychiatric conditions group, without psychiatric diagnosis group	RYGB	Evaluation of the differences in demographics, physical comorbidities, and psychological conditions before surgery and behavioural noncompliance after surgery.	At 1 year, overall mean percent weight loss exceeded 35%, and mean BMI was 32. These outcomes were remarkably similar and not significantly different for those with bipolar disorder, other psychological conditions, and those without.
Legenbauer et al. 2011 [103]	Bochum, Germany	Prospective, longitudinal study	153	38.8%	66.9% F	Lifetime diagnosis of a mental disorder was defined as presence of a mental disorder only in the past. Body weight was measured at baseline, 1 year after baseline, and 4 years after baseline.	Bariatric surgery	Munich-CIDI to assess current and lifetime depressive disorders including major depression and dysthymia	Depression was not associated with weight changes at the 1-year follow-up. After 4 years: depression (current and lifetime) predicted smaller body mass index loss, whereas lifetime diagnosis of eating disorder was associated with greater weight loss.
Semanschin-Doerr DA et al. 2010 [50]	Cleveland, USA	Prospective, longitudinal study	104		78.6% white, 71.2% F	43.1% had a current, and 62.5% a lifetime, diagnosis of a mood disorder. 1-Year follow-up	Sleeve gastrectomy		Patients with current or lifetime mood disorders had a significantly lower %EWL. After removing patients with bipolar disorder from the analyses, no significant differences were found in the %EWL between patients with and without a lifetime history of depressive disorders.
Thonney et al. 2010 [56]	Geneva, Switzerland	Prospective, longitudinal study	43	39.3 ± 1.4	F	2 years follow up	RYGB	BDI; Hospital Anxiety and Depression Scale	Decreases in depression, anxiety (P <.05), and eating disorder scores were measured 2 years after surgery. Both excess weight loss and change in body mass index were associated with improvements in all measured psychological outcomes 2 years after surgery.
Coleman et al. 2010 [55]	Pasadena (USA)	Prospective, longitudinal study	110	43,5	F	1-year follow up	RYGB	Evaluation of the differences in demographics, physical comorbidities, and psychological conditions before surgery and behavioural noncompliance after surgery.	The only differences between patients with successful and unsuccessful weight loss were found for sleep apnea before surgery, exercise noncompliance in the second year after surgery, and dumping syndrome in the first 6 months after surgery.
Legenbauer et al. 2009 [49]	Dortmund,Germany	Prospective, longitudinal study	531 (151 BS)	38.8 ± 10.3	66.9 % F in BS group, white	To investigate the impact of current mental disorders on weight loss: 4-year follow-up	Comparison participants in a conventional treatment, obesity surgery patient, obese control individuals		Patients with a depressive and/or anxiety disorder lost significantly less weight compared with those without a comorbid mental diagnosis. Binge eating behaviour at baseline did not predict weight loss at 4-year followup.
Kalarchian et al. 2008 [69]	Pittsburgh, USA	Prospective, longitudinal study	207 (97.2% white)	45.8 ± 9.5	83.1% F; 16.9% M	6-month follow up	RYGB	SCID-I	Lifetime mood disorder was associated with a smaller decrease in BMI.
Averbukh Y et al. 2003 [22]	New York	Prospective, longitudinal study	145			to evaluate the association between pre-surgical severity of depression and success at weight loss following Roux-en-Y gastric bypass (RYGBP)	RYGB	BDI	Weight loss at 1 year was significantly related to the BDI score before surgery. BDI score was also found to be a significant predictor of the amount of weight lost (kg) 1 year after surgery.

F: Female; M: Male; BS: Bariatric Surgery; BMI: Body mass Index; RYGB: Roux-Y-Gastric Bypass; LAGB: Laparoscopic Adjustable Gastric Banding; MDD: Major Depressive Disorder; BD: Bipolar Disorder; BED: Binge Eating Disorder; SCID-I: Structured Clinical Interview for DSM IV Axis I disorders; Ham-D: Hamilton Rating Scale for Depression; BDI: Beck Depression Inventory; Beck Depression Inventory-II (BDI-II); QoL: Quality of Life