Stilul de viață dezechilibrat: legătura dintre obezitate și afecțiunile psihiatrice

Introduction

Obesity, a global pandemic, has shown alarming increases in recent decades. It is estimated that, by 2030, approximately one billion people globally will be diagnosed with obesity, given that, currently, worldwide, there are approximately 300 million people diagnosed with depression⁽¹⁾. According to specialized studies, the female sex is more prone to depression and obesity, a possible risk factor being pregnancy, for both chronic pathologies^(2,3).

The diagnosis and staging of obesity are made easiest and cheapest with the help of anthropometric indices, of which, the one that has gained ground, being most widely used today, is the Body Mass Index (BMI). Defined as a chronic pathology, obesity is associated with an inflammatory status that translates into an increased secretion of proinflammatory cytokines, and these cytokines can have negative effects on the expression of neurotransmitters^(4-6).

Secondary obesity, which is based on an unbalanced lifestyle, is the main cause of obesity, thus, the changes brought about in recent decades, in all branches of lifestyle, have led to a constant and alarming increase in obesity cases, with gloomy forecasts for the coming years, in the absence of effective measures to reduce and prevent this pandemic^(7,8).

It is important to understand that, when we talk about an unbalanced lifestyle, we must take into account multiple factors which, when summed up, lead to the percentages that have transformed obesity into a burden on the medical system worldwide^(9,10). Thus, excessive calorie consumption in relation to necessity, the multitude of processed food offers and junk food, the lack of quantitative and qualitative sleep, the lack of physical exercise, or too much time allocated to electronic devices, in contrast to the time spent in nature and with family members or friends, are key elements in the installation of obesity⁽⁹⁾. This is why it is not professional to focus only on the nutritional aspect when dealing with an obese patient; failure to identify other predisposing factors leads to their failure to be resolved and, ultimately, to the failure of the therapeutic plan.

Chronic stress is a risk factor for obesity, but it is also the most common disorder associated with depression. Cortisone, eliminated in stressful situations, when chronically present, interferes with carbohydrate metabolism, leading to the installation of insulin resistance⁽⁵⁾.

The obese patient needs a multidisciplinary team in which the psychiatrist must be part, due to the fact that obesity – especially when it has been present for a long period – inevitably associates disorders in this area which, if unidentified, will make the weight loss process more difficult and, at the same time, will deepen.

Low self-esteem, isolation and mild-to-severe depression are the main psychiatric disorders that accompany the obese patient. If we return to the factors responsible for lifestyle – namely, the quality and quantity of sleep, the absence of entourage, the lack of time spent in nature –, we can conclude that the psychiatric disorder has a double origin, both in the factors favoring obesity and in obesity itself.

It is essential to understand that depression, as well as the rest of the psychiatric disorders, is based on multiple mechanisms, but these two – depression and obesity – are often correlated, and in recent years, both pathologies have recorded significant increases^(11,12).

The purpose of this paper is to draw attention to the psychiatric disorders that appear silently in the life of the obese patient, but are an essential pillar for the effective therapeutic management of obesity, and also to underscore the fact that depression and obesity represent two bidirectional chronic pathologies, being necessary for both to be treated. We also want to join the global fight against obesity and to – once again – raise the alarm about this global health issue. Last but not least, we emphasize the need for a multidisciplinary therapeutic management in front of an obese patient.

Materials and method

This narrative review aimed to synthesize evidence-based on guidelines and clinical trials about the impact of obesity in the psychiatric field. A structured search was performed in PubMed, Scholar Academic and Google Scholar for records published between 2020 and 2025. The inclusion criteria included peer-reviewed publications in English reporting randomized controlled trials, systematic reviews, meta-analyses, large observational cohorts or clinical guidelines on the impact of obesity on psychiatric health. The search terms used were: obesity, depression, psychiatric disorder and obesity, behavioral therapy.

Results and discussion

According to the analysis, there is a reciprocal relationship between obesity and depression, resulting from all studies, and the basis of this relationship is favored by the lifestyle of modern man^(4,11).

The treatment of obesity comes with the reduction of mental symptoms, a visible action also in the case of the therapeutic management of pathologies in the depressive sphere. It should be remembered that, in both pathologies, the patient-centered approach is essential for an efficient management, and the existence of exogenous factors, an integrated part of the unbalanced lifestyle, must be carefully analyzed in each patient^(13,14).

Although they are based on different mechanisms of production, depression and obesity also associate certain common characteristics, the chronic inflammation found in obesity, against the background of excess weight, representing an essential pillar in the installation of depression^(11,15,16).

There are studies suggesting that the HPA axis becomes hyperactive in the presence of biomarkers associated with obesity – namely, adiponectin, leptin, ghrelin and resistin^(17-19). It is well known that, in depressive pathologies, the HPA axis is hyperactive, thus this mechanism can also explain the link between obesity and depression. Excess adipose tissue is associated with reduced levels of adiponectin, which has anti-inflammatory properties, partially explaining the inflammatory status in obesity⁽¹⁵⁾. The imbalance of the HTA axis also occurs due to the fact that leptin and resistin have increased values; thus, in the presence of an unbalanced HPA axis, an excess of cortisol is produced, which is identified in the etiology of depression⁽¹¹⁾.

Low adiponectin levels have been correlated with the severity of major depressive disorder. Thus, Islam et al. (2022) suggest that adiponectin levels could be a useful marker in detecting the risk of depression, because adiponectin levels were also reduced in recurrent disorders, but also in evaluating therapeutic management^(20,21).

Resistin – another well-known biomarker in obesity, because it shows increased values ​​in these patients – has the role of reducing the levels of dopamine and noradrenaline and, through these mechanisms, it could individually contribute to the installation of depressive pathologies^(18,19,22).

Inflammation caused by excess weight leads to increased levels of proinflammatory cytokines, in contrast to the reduction of anti-inflammatory ones. Therefore, the idea of ​​using IL-6, TNF-alpha and CRP, present in obesity in high percentages, as markers in depression is being discussed, due to the fact that their high presence in the body leads to an amplification of the clinical picture of depressive disorders. Luppino et al. reveal that the risk of developing depression in obese patients was 55%, and those with depression had a 58% risk of developing obesity.⁽²³⁾. Also, obese people have a 32% higher risk of developing depression compared to normal-weight people⁽²⁴⁾.

Female sex is more often incriminated in the statistics of these two chronic pathologies, obesity and depression. Pregnancy is the time when women have a high chance of developing depression, because of the major physical and hormonal changes their body goes through. Therefore, health professionals should pay attention to signs of depression during pregnancy, not just postpartum, when it is well known that the risk of developing depression is high, but unfortunately, it is not diagnosed and treated in all cases, from the beginning^(3,5,25).

The excess weight that a woman often remains with after pregnancy is a major contributing factor to triggering depression in the first postpartum year. Not only is the mother affected, but the entire family, and the infant feels the hardest, because he spends the most time with the mother and, according to specialized studies, a depressed mother leads to an inharmonious development (both physically and psycho-emotionally) of the newborn and, subsequently, for the infant^(27-29). Thus, in front of a pregnant woman or a patient who has just given birth, a multidisciplinary team is also necessary for the prevention of chronic problems or for the therapeutic success.

Lack of sufficient quality and quantity of sleep leads to raising levels of ghrelin, a hormone known to be associated with increased food intake. At the same time, interrupted sleep leads to insulin resistance, which in turn is a contributing factor to depression and obesity⁽⁵⁾.

Intensely analyzed in recent decades, the imbalance of the intestinal microbiome is the basis of multiple pathologies. The evidence of the bidirectional link between the two pathologies – depression and obesity – is also stabilized by prebiotics and probiotics. According to studies, strains of Lactobacillus and Bifidobacterium have associated positive changes in both conditions⁽²⁹⁾.

Psychological trauma is a predisposing factor for eating disorders, which is why it is important to take a detailed history with an obese patient, and then, regardless of the nature of the specialization, to include a psychiatric consultant as part of the therapeutic management. A systematic review showed a 90% association between trauma and eating disorders⁽³⁰⁾.

A study conducted in Seattle analyzed the mood of subjects after meals high in carbohydrates, finding that they increased the intensity of depressive disorders⁽³¹⁾.

Another study analyzed the effect of physical activity on depression, and the symptoms were reduced in patients who used to do exercises⁽³²⁾.

Lifestyle change remains the essential pillar in the face of obese patients and, regardless of whether they associate depression or not, psychiatric consultation is important for lifestyle change. According to studies, self-motivation is the most important factor responsible for lifestyle change, and for sufficient self-motivation to change, sometimes appropriate therapies are necessary. Nutritional psychoeducation and motivational interviewing are effective methods to increase self-motivation, and studies have shown significantly better results in patients with a high level of motivation⁽³³⁾.

Conclusions

The obese patient requires a multidisciplinary approach, and psychiatric consultation is the essential link for the favorable evolution of the case.

Obesity is a chronic disease, responsible for numerous other chronic pathologies that transform this lifestyle imbalance into a significant risk factor for morbidity and mortality, in the 21^st century, also becoming a burden for the global medical system and causing huge costs.

The association between obesity and depression is a reality that requires appropriate attention. Also, biomarkers known in obesity are suggested as possible prognostic markers for evaluation and therapeutic management in depression. In this direction, extensive studies are needed, on significant cohorts of patients.

We believe it is time to intervene promptly through health policies for prevention, but also for treatment, in those cases where obesity is already installed, and apart from these policies, let us not omit the psychiatrist’s role for the essential therapeutic management.   

Corresponding author: Dragoș Mandroc E-mail: mandrocd@gamil.com

Conflict of interest: none declared.

Financial support: none declared.

This work is permanently accessible online free of charge and published under the CC-BY licence.