Adolescents who have had bariatric surgery do not improve their mental health despite significant and permanent weight loss, according to the largest long-term study of young people who have undergone bariatric surgery, conducted at Lund University and Karolinska Institutet, among others. Indeed, the study - the largest long-term study in the world of young people who have had bariatric surgery - also found surgery also increases the risk of early alcohol problems.
The researchers studied mental health problems - before and after surgery - among all young people in Sweden who underwent bariatric surgery between 2007 and 2017. The study was conducted using register data, which enabled the scope of the study and facilitated comparisons with other groups in society. It found that young people who underwent surgery were more likely to have received treatment and medication for mental health problems already five years before the surgery.
The study included 1,554 adolescents (<21 years) with severe obesity underwent bariatric surgery between 2007 and 2017, 1169 (75%) of whom were female. Five years before the matched index date, 95 (6.2%) of 1,535 surgery patients and 370 (2·5%) of 14,643 matched adolescents had a psychiatric health-care visit (prevalence difference 3.7%; 95% CI 2.4–4.9), whereas 127 (9.8%) of 1,295 surgery patients and 445 (3.6%) of 12,211 matched adolescents filled a psychiatric drug prescription (prevalence difference 6.2%; 95% CI 4.5–7.8).
The year before the matched index date, 208 (13.4%) of 1,551 surgery patients and 844 (5.5%) of 15,308 matched adolescents had a psychiatric health-care visit (prevalence difference 7.9%; 95% CI 6.2–9.6), whereas 319 (20.6%) of 1,551 surgery patients and 1,306 (8.5%) of 15,308 matched adolescents filled a psychiatric drug prescription (prevalence difference 12.0%; 10·0–14.1). The prevalence difference in psychiatric health-care visits peaked nine years after the matched index date (12.0%; 95% CI 9.0–14.9), when 119 (17.6%) of 675 surgery patients and 377 (5.7%) of 6,669 matched adolescents had a psychiatric health-care visit.
"Although mental illness generally increases between the ages of 15 and 21, for this group, the need for treatment increased faster than for young people in general," explained Kajsa Järvholm, Associate Professor of Psychology at Lund University.
Unfortunately, this pattern continued even after obesity surgery; the young people who had the surgery continued to have a greater need for mental health treatment than their peers.
"Obesity surgery has very positive effects on weight, blood sugar, and blood pressure control, but when it comes to mental health, it does not get better or worse after bariatric surgery," added Martin Neovius, Professor of Clinical Epidemiology at Karolinska Institutet.
The prevalence difference in filled psychiatric drug prescription was highest ten years after the matched index date (20.4%; 15.9–24.9), when 171 (36.5%) of 469 surgery patients and 739 (16.0%) of 4,607 matched adolescents filled a psychiatric drug prescription. The year before the matched index date, 19 (1.2%) of 1551 surgery patients and 155 (1.0%) of 15304 matched adolescents had a health-care visit associated with a substance use disorder diagnosis (mean difference 0.2%, 95% CI –0.4 to 0.8). Ten years after the matched index date, the prevalence difference had increased to 4.3% (95% CI 2.3–6.4), when 24 (5.1%) of 467 surgery patients and 37 (0.8%) of 4,582 matched adolescents had a health-care visit associated with a substance use disorder diagnosis.
Additional findings from the new study include an increase in dependency diagnoses, particularly on alcohol, in the surgical group, both in comparison to pre-surgery and to young people in general.
The paper, ‘Mental health from 5 years before to 10 years after bariatric surgery in adolescents with severe obesity: a Swedish nationwide cohort study with matched population controls’, was published in The Lancet Child & Adolescent Health.
The study was funded by the Swedish Research Council, Swedish Research Council for Health, Working Life and Welfare.
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