Obesity diagnosis significantly increases the probability of a broad spectrum of mental disorders in all age groups m- including depression, nicotine addiction, psychosis, anxiety, eating and personality disorders, according to study by the Medical University of Vienna and the Complexity Science Hub Vienna.
The research team analysed a population-based dataset of all inpatient hospitalisations in Austria from 1997 to 2014 in order to determine the relative risks of concomitant diseases in obesity and to identify statistically significant gender differences.
"In order to find out which illness typically appeared prior and subsequently to the obesity diagnosis, we had to develop a new method. This allowed us to determine whether there are trends and typical patterns in the occurrence of diseases," explained co-first author, Dr Elma Dervic from the Complexity Science Hub. "In case of all co-diagnoses, with the exception of the psychosis spectrum, obesity was in all likelihood the first diagnosis made prior to the manifestation of a psychiatric diagnosis. "
Until now, physicians often assumed that psychopharmacological drugs were the cause for the link between mental disorders and diabetes.
"This may be true for schizophrenia, where we see the reverse chronological order, but our data does not support this for depression or other psychiatric diagnoses," added first author, Dr Alexander Kautzky from the Department of Psychiatry and Psychotherapy at MedUni Vienna.
However, whether obesity directly affects mental health or whether early stages of psychiatric disorders are inadequately recognised is not yet known. Surprisingly, the researchers found significant gender differences for most disorders - with women showing an increased risk for all disorders except schizophrenia and nicotine addiction. While 16.66% of all men with obesity also suffer from nicotine addiction, this is only the case in up to 8.58% of women with obesity.
However, the opposite is true for depression - the rate of diagnosed depressive episodes was almost three times higher in women with obesity (13.3% obese; 4.8% non-obese), men with obesity were affected twice as often (6.61% obese; 3.21% non-obese).
The fact that the disease promotes metabolic disorders and serious cardio-metabolic complications (diabetes mellitus, arterial hypertension and dyslipidaemia) has already been extensively researched.
According to the current study, obesity often precedes severe mental disorders emphasises its importance as a risk factor for health problems of all children. This is primarily true for young age groups, where the risk is most pronounced. For this reason, thorough screening for mental health problems in patients with obesity is urgently needed to facilitate prevention or ensure that appropriate treatment can be given.
"From a clinical point of view, these results emphasise the need to raise awareness of psychiatric diagnoses in obese patients and, if necessary, to consult specialists at an early stage of diagnosis," said study leader, Dr Michael Leutner from the Department of Internal Medicine II at MedUni Vienna.
The outcomes were reported in the paper, ‘Obesity as pleiotropic risk state for metabolic and mental health throughout life’, published in Translational Psychiatry.
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