Addressing the dual impact of obesity and mental health

Obesity, often referred to as a epidemic, affects one in eight people globally. In South Africa, an estimated 50% of the population are overweight or obese, according to a recent study by the Human Sciences Research Council. KwaZuluNatal reported the highest prevalence of obesity (39.4%).1,2

T

he growing prevalence of childhood obesity is particularly concerning, note Segal and Gunturu. Around 37 million children <5-year are overweight and >390 million older children and adolescents are overweight of which ~160 million are living with obesity.1

In 2019, 16% of South African children aged five- to nine-years (>91 100) and 22% of those aged 10- to 14-years (>120 300) were classified as overweight or obese. Overall, 18% of children aged 15- and 17-years (>91 800) were found to be overweight or obese. The rate was significantly higher for girls (22%) than boys (15%).3,4

Stigmatisation leads to psychological challenges

Individuals living with obesity often face societal stigma and discrimination, leading to psychological challenges. Psychological challenges stem from a combination of biological, psychological, and social factors such as stigmatisation and discrimination. Biologically, genetic predispositions, hormonal imbalances, chronic inflammation, insulin resistance, and changes in brain structure linked to obesity can exacerbate psychological conditions like depression and anxiety. Depression and anxiety negatively impact overall quality of life (QoL) and can lead to maladaptive eating (eg binge or emotional eating) behaviours.1

Individuals living with obesity face an 18%-55% increased risk of developing depression, and those with depression are 37%-58% more likely to develop obesity. Global data indicates a growing burden of both obesity and mood disorders, with a stronger link between obesity and depression observed in women and younger individuals.1

Obesity-related psychological issues can cause complications 

Psychological challenges linked to obesity can lead to significant complications affecting mental and physical health and overall QoL. Some key complication include:1

Managing comorbid obesity and psychological challenges

A recent review of key interventions in the management of comorbid obesity and psychological challenges in individuals living with obesity recommend the following:5

• Integrate cognitive behavioural therapy (CBT) with lifestyle modifications to address both psychological and weight-related issues effectively.

• Implement interventions like the Integrated Coaching for Better Mood and Weight programmes, which synergises obesity and depression treatment strategies.

• Tailor interventions to individual needs, emphasising personalised CBT rather than one-size-fits-all group therapy to enhance outcomes.

• Provide comprehensive nutritional education, including information on gut microbiota, to support weight loss and improve mental health.

• Promote at least 150-minutes of moderate to vigorous physical activity per week as part of lifestyle modification programmes.

• Regularly assess both weight and mental health outcomes to evaluate intervention effectiveness and adjust treatment plans accordingly.

• Use stepped-care approaches that allow for gradual intensification of treatment, such as introducing acceptance-based behavioural treatment when initial weight loss goals are not met.

• Incorporate eHealth resources and self-guided interventions to engage participants and facilitate weight loss while addressing mental health challenges.

• Conduct secondary analyses to identify factors that mediate outcomes, which can inform the development of future interventions.

• Recognise and mitigate barriers that may prevent individuals, especially men, from seeking help for both obesity and depression, promoting accessible and appealing intervention options.

The role of pharmacotherapy

In terms of pharmacotherapy, it is important to note that many psychotropic medications such as antidepressants used to treat mood disorders such as depression and anxiety have obesogenic effects, while several weight-loss medications can have psychological effects.6

When considering pharmacotherapy for patients with obesity and a mood disorder, it is crucial to understand the weight-related impacts of psychotropic drugs, and the psychological effects of anti-obesity medications (AOMs).6

Antidepressants generally cause more modest weight gain compared to other psychotropic drugs such as antipsychotics, with medications such as amitriptyline, mirtazapine, and paroxetine being associated with gains of up to 2.7kg after long-term use. On the other hand, bupropion is more likely to cause weight loss.7

A 2020 study by Tham et al assessed the effectiveness, tolerability, impact on eating behaviours, and psychological safety of AOMs in individuals living with obesity, metabolic syndrome and psychological challenges. Follow-up was 12-months.8

At the end of the study period, results showed an average weight loss of 11.79kg (12.1%), a body mass index (BMI) reduction of 3.90kg/m², and a 12.6cm decrease in waist circumference. The proportion of participants with good glycaemic control increased from 28.6% to 80.7%, hypercholesterolaemia dropped from 85.2% to 29.9%, and hypertension rates fell from 88.9% to 52%. Depression, anxiety, and stress levels significantly decreased, while eating behaviours improved.8

AOMs were generally well tolerated, but topiramate was associated with increased psychiatric side effects, including worsened mood (28.2%) and suicidality (30.8%). Overall, AOMs can contribute to significant weight loss and improved metabolic health when combined with lifestyle interventions, though caution is needed with certain medications, concluded the authors.8

Conclusion

Obesity has significant psychological effects, with individuals often facing societal stigma and discrimination, leading to worsened mental health. This association between obesity and depression highlights the need for a holistic approach to treatment. AOMs can be effective in promoting weight loss, but some may have negative psychiatric side effects. When managing patients with both obesity and mood disorders such as depression and anxiety, it is essential to carefully consider the weight-related impacts of antidepressants and the psychological effects of AOMs. A combination of lifestyle interventions, CBT, and pharmacotherapy tailored to individual needs offers the best outcomes.

References are available on request.