Interventions for the management of obesity in people with bipolar disorder

BACKGROUND

Bipolar disorder is one of the most common serious mental illnesses, affecting approximately 60 million people worldwide. Characterised by extreme alterations in mood, cognition, and behaviour, bipolar disorder can have a significant negative impact on the functioning and quality of life of the affected individual. Compared with the general population, the prevalence of comorbid obesity is significantly higher in bipolar disorder. Approximately 68% of treatment seeking bipolar patients are overweight or obese. Clinicians are aware that obesity has the potential to contribute to other physical health conditions in people with bipolar disorder, including diabetes, hypertension, metabolic syndrome, cardiovascular disease, and coronary heart disease. Cardiovascular disease is the leading cause of premature death in bipolar disorder, happening a decade or more earlier than in the general population. Contributing factors include illness-related factors (mood-related factors, i.e. mania or depression), treatment-related factors (weight implications and other side effects of medications), and lifestyle factors (physical inactivity, poor diet, smoking, substance abuse). Approaches to the management of obesity in individuals with bipolar disorder are diverse and include non-pharmacological interventions (i.e. dietary, exercise, behavioural, or multi-component), pharmacological interventions (i.e. weight loss drugs or medication switching), and bariatric surgery.

OBJECTIVES

To assess the effectiveness of interventions for the management of obesity in people with bipolar disorder.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR) and the Cochrane Central Register for Controlled Trials (CENTRAL) to February 2019. We ran additional searches via Ovid databases including MEDLINE, Embase, and PsycInfo to May 2020. We searched the World Health Organization (WHO) trials portal (International Clinical Trials Registry Platform (ICTRP)) and ClinicalTrials.gov. We also checked the reference lists of all papers brought to full-text stage and all relevant systematic reviews.

SELECTION CRITERIA

Randomised controlled trials (RCTs), randomised at the level of the individual or cluster, and cross-over designs of interventions for management of obesity, in which at least 80% of study participants had a clinical diagnosis of bipolar disorder and comorbid obesity (body mass index (BMI) ≥ 30 kg/m²), were eligible for inclusion. No exclusions were based on type of bipolar disorder, stage of illness, age, or gender. We included non-pharmacological interventions comprising dietary, exercise, behavioural, and multi-component interventions; pharmacological interventions consisting of weight loss medications and medication switching interventions; and surgical interventions such as gastric bypass, gastric bands, biliopancreatic diversion, and vertical banded gastroplasty. Comparators included the following approaches: dietary intervention versus inactive comparator; exercise intervention versus inactive comparator; behavioural intervention versus inactive comparator; multi-component lifestyle intervention versus inactive comparator; medication switching intervention versus inactive comparator; weight loss medication intervention versus inactive comparator; and surgical intervention versus inactive comparator. Primary outcomes of interest were changes in body mass, patient-reported adverse events, and quality of life.

DATA COLLECTION AND ANALYSIS

Four review authors were involved in the process of selecting studies. Two review authors independently screened the titles and abstracts of studies identified in the search. Studies brought to the full-text stage were then screened by another two review authors working independently. However, none of the full-text studies met the inclusion criteria. Had we included studies, we would have assessed their methodological quality by using the criteria recommended in the Cochrane Handbook for Systematic Reviews of Interventions. We intended to combine dichotomous data using risk ratios (RRs), and continuous data using mean differences (MDs). For each outcome, we intended to calculate overall effect size with 95% confidence intervals (CIs).

MAIN RESULTS

None of the studies that were screened met the inclusion criteria.

AUTHORS' CONCLUSIONS

None of the studies that were assessed met the inclusion criteria of this review. Therefore we were unable to determine the effectiveness of interventions for the management of obesity in individuals with bipolar disorder. Given the extent and impact of the problem and the absence of evidence, this review highlights the need for research in this area. We suggest the need for RCTs that will focus only on populations with bipolar disorder and comorbid obesity. We identified several ongoing studies that may be included in the update of this review.

Cannabinoids in health and disease: pharmacological potential in metabolic syndrome and neuroinflammation

The use of different natural and/or synthetic preparations of Cannabis sativa is associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena. In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving. Moreover, cannabinoid agonists are able to reduce inflammatory response. In this review a brief history of cannabinoids and the protagonists of the endocannabinoidergic system, i.e. synthesis and degradation enzymes and main receptors, will be described. Furthermore, the pharmacological effects of cannabinoids will be outlined. An overview of the involvement of the endocannabinoidergic system in neuroinflammatory and metabolic pathologies will be made. Finally, particular attention will also be given to the new pharmacological entities acting on the two main receptors, cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), with particular focus on the neuroinflammatory and metabolic mechanisms involved.

Human brown adipose tissue-function and therapeutic potential in metabolic disease

There has been a resurgence of interest in brown adipose tissue (BAT) over the last decade. Key to this has been our ability to accurately image it, which has improved significantly. The role of BAT in regulating energy expenditure is important, and its pharmacological manipulation may hold therapeutic potential in metabolic disease. There is ample evidence of BAT activation by cold exposure, and pharmacological utilisation of similar pathways, using B3 receptor agonists holds promise since the development of selective agonists with limited cross-reactivity has rekindled interest. Endogenous agents like irisin, FGF21 and certain gut hormones may hold value as BAT activators. Other agents such as steroid hormones may also hold therapeutic potential, although short-term worsening of metabolic profile remains problematic. Clearly, pharmacological manipulation of BAT is important, and thanks to recent advances we may one day be able to add such agents to our anti-obesity arsenal.

The Obesity-Impulsivity Axis: Potential Metabolic Interventions in Chronic Psychiatric Patients

Pathological impulsivity is encountered in a broad range of psychiatric conditions and is thought to be a risk factor for aggression directed against oneself or others. Recently, a strong association was found between impulsivity and obesity which may explain the high prevalence of metabolic disorders in individuals with mental illness even in the absence of exposure to psychotropic drugs. As the overlapping neurobiology of impulsivity and obesity is being unraveled, the question asked louder and louder is whether they should be treated concomitantly. The treatment of obesity and metabolic dysregulations in chronic psychiatric patients is currently underutilized and often initiated late, making correction more difficult to achieve. Addressing obesity and metabolic dysfunction in a preventive manner may not only lower morbidity and mortality but also the excessive impulsivity, decreasing the risk for aggression. In this review, we take a look beyond psychopharmacological interventions and discuss dietary and physical therapy approaches.

Functional neuroimaging in obesity and the potential for development of novel treatments

Recently, exciting progress has been made in understanding the role of the CNS in controlling eating behaviour and in the development of overeating. Regions and networks of the human brain involved in eating behaviour and appetite control have been identified with neuroimaging techniques such as functional MRI, PET, electroencephalography, and magnetoencephalography. Hormones that regulate our drive to eat (eg, leptin, insulin, and glucagon-like peptide-1) can affect brain function. Defects in central hunger signalling are present in many pathologies. On the basis of an understanding of brain mechanisms that lead to overeating, powerful neuroimaging protocols could be a future clinical approach to allow individually tailored treatment options for patients with obesity. The aim of our Review is to provide an overview of neuroimaging approaches for obesity (ie, neuroimaging study design, questions which can be answered by neuroimaging, and limitations of neuroimaging techniques), examine current models of central nervous processes regulating eating behaviour, summarise and review important neuroimaging studies investigating therapeutic approaches to treat obesity or to control eating behaviour, and to provide a perspective on how neuroimaging might lead to new therapeutic approaches to obesity.

Past, Present, and Future of Pharmacologic Therapy in Obesity

Medications for obesity management can be divided into 4 groups: antidepressants (naltrexone/bupropion), stimulants (phentermine, phendimetrazine, diethylpropion, phentermine/topiramate), fat blockers (orlistat), and diabetes medications (liraglutide). Each group has specific therapeutic effects, adverse effects, and costs. Two medications are indicated for long-term use in obesity: lorcaserin and orlistat. Other available medications are for short-term use. High cost makes many of these medications inaccessible for underserved and poor patients. Because of misuse potential, many obesity medications are also classified as controlled substances. There are no medications currently approved for use in pregnant or lactating women.

Cardiotoxicity screening: a review of rapid-throughput in vitro approaches

Cardiac toxicity represents one of the leading causes of drug failure along different stages of drug development. Multiple very successful pharmaceuticals had to be pulled from the market or labeled with strict usage warnings due to adverse cardiac effects. In order to protect clinical trial participants and patients, the International Conference on Harmonization published guidelines to recommend that all new drugs to be tested preclinically for hERG (Kv11.1) channel sensitivity before submitting for regulatory reviews. However, extensive studies have demonstrated that measurement of hERG activity has limitations due to the multiple molecular targets of drug compound through which it may mitigate or abolish a potential arrhythmia, and therefore, a model measuring multiple ion channel effects is likely to be more predictive. Several phenotypic rapid-throughput methods have been developed to predict the potential cardiac toxic compounds in the early stages of drug development using embryonic stem cells- or human induced pluripotent stem cell-derived cardiomyocytes. These rapid-throughput methods include microelectrode array-based field potential assay, impedance-based or Ca(2+) dynamics-based cardiomyocytes contractility assays. This review aims to discuss advantages and limitations of these phenotypic assays for cardiac toxicity assessment.

Control of Body Weight by Eating Behavior in Children

Diet, exercise, and pharmacological interventions have limited effects in counteracting the worldwide increase in pediatric body weight. Moreover, the promise that individualized drug design will work to induce weight loss appears to be exaggerated. We suggest that the reason for this limited success is that the cause of obesity has been misunderstood. Body weight is mainly under external control; our brain permits us to eat under most circumstances, and unless the financial or physical cost of food is high, eating and body weight increase by default. When energy-rich, inexpensive foods are continually available, people need external support to maintain a healthy body weight. Weight loss can thereby be achieved by continuous feedback on how much and how fast to eat on a computer screen.