Monoamine oxidase inhibitors and weight gain

Monoamine oxidase mediated oxidative stress: a potential molecular and biochemical crux in the pathogenesis of obesity

Obesity has become a global health concern with an increasing prevalence as years pass by but the researchers have not come to a consensus on the exact pathophysiological mechanism underlying this disease. In the past three decades, Monoamine Oxidases (MAO), has come into limelight for a possible involvement in orchestrating the genesis of obesity but the exact mechanism is not well elucidated. MAO is essentially an enzyme involved in the catabolism of neurotransmitters and other biogenic amines to form a corresponding aldehyde, hydrogen peroxide (H2O2) and ammonia. This review aims to highlight the repercussions of MAO's catabolic activity on the redox balance, carbohydrate metabolism and lipid metabolism of adipocytes which ultimately leads to obesity. The H2O2 produced by these enzymes seems to be the culprit causing oxidative stress in pre-adipocytes and goes on to mimic insulin's activity independent of its presence via the Protein Kinase B Pathway facilitating glucose influx. The H2O2 activates Sterol regulatory-element binding protein-1c and peroxisome proliferator activated receptor gamma crucial for encoding enzymes like fatty acid synthase, acetyl CoA carboxylase 1, Adenosine triphosphate-citrate lyase, phosphoenol pyruvate carboxykinase etc., which helps promoting lipogenesis at the same time inhibits lipolysis. More reactive oxygen species production occurs via NADPH Oxidases enzymes and is also able activate Nuclear Factor kappa B leading to inflammation in the adipocyte microenvironment. This chronic inflammation is the seed for insulin resistance.

Clinically Relevant Drug Interactions with Monoamine Oxidase Inhibitors

Monoamine oxidase inhibitors (MAOI) are a class of drugs that were originally developed for the treatment of depression but have since been expanded to be used in management of affective and neurological disorders, as well as stroke and aging-related neurocognitive changes. Ranging from irreversible to reversible and selective to non-selective, these drugs target the monoamine oxidase (MAO) enzyme and prevent the oxidative deamination of various monoamines and catecholamines such as serotonin and dopamine, respectively. Tyramine is a potent releaser of norepinephrine (NE) and is found in high concentrations in foods such as aged cheeses and meats. Under normal conditions, NE is unable to accumulate to toxic levels due to the presence of MAO-A, an enzyme that degrades neurotransmitters, including NE. When MAO-A is inhibited, the capacity to handle tyramine intake from the diet is significantly reduced causing the brain to be vulnerable to overstimulation of postsynaptic adrenergic receptors with as little as 8-10 mg of tyramine ingested and can result in life-threatening blood pressure elevations. In addition to adverse reactions with certain foods, both older and newer MAOIs can negatively interact with both sympathomimetic and serotonergic drugs. In general, patients on a MAOI want to avoid two types of medications: those that can elevate blood pressure via sympathomimetic actions (e.g., phenylephrine and oxymetazoline) and those that can increase serotonin levels via 5-HT reuptake inhibition (e.g., dextromethorphan, chlorpheniramine, and brompheniramine). Illicit drugs that stimulate the central nervous system such as ecstasy (MDMA, 3,4-methylenedioxymethamphetamine) act as serotonin releasers. Patient involvement is also crucial to ensure any interaction within the healthcare setting includes making other providers aware of a MAOI prescription as well as avoiding certain OTC medications that can interact adversely with MAOIs.

Monoamine Oxidase Inhibitors (MAOIs) in Psychiatric Practice: How to Use them Safely and Effectively

Monoamine oxidase inhibitors (MAOIs) were among the first licensed pharmacological treatments for patients with depression but over time have fallen out of mainstream clinical use. This has led to a loss of clinician training opportunities and reduced availability of MAOIs for prescribing. This article provides a concise and practical overview of how to use MAOIs safely and effectively in psychiatric practice. We consider the history of MAOIs, why they are not used more frequently, their mechanisms of action, availability, indications and efficacy, general tolerability, withdrawal symptoms, and safety considerations (including hypertensive reactions and serotonin syndrome). Practical advice is given in terms of dietary restrictions, interactions with other medications (both prescribed and non-prescribed), and how prescribers can stop and switch MAOIs, both within the drug class and outside of it. We also provide advice on choice of MAOI and treatment sequencing. Lastly, we consider emerging directions and potential additional indications.

Antidepressant Medications and Weight Change: A Narrative Review

Antidepressant medications are the first-line treatment option for moderate to severe major depressive disorder. However, most antidepressants have numerous documented adverse events, including cardiometabolic effects and weight gain, which are major public health concerns. Antidepressant agents provide varying risk of associated weight gain, including significant within-class differences. Some agents, such as mirtazapine, show significant levels of weight gain, while others, such as bupropion, demonstrate weight-loss effects. Current findings suggest the role of histamine and serotonin off-target appetite-promoting pathways in adverse weight-gain effects. Therefore, controlling for undesired weight effects is an important consideration for the selection of antidepressants.

Past, Present and Future Anti-Obesity Effects of Flavin-Containing and/or Copper-Containing Amine Oxidase Inhibitors

Background: Two classes of amine oxidases are found in mammals: those with a flavin adenine dinucleotide as a cofactor, such as monoamine oxidases (MAO) and lysine-specific demethylases (LSD), and those with copper as a cofactor, including copper-containing amine oxidases (AOC) and lysyl oxidases (LOX). All are expressed in adipose tissue, including a semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 (SSAO/VAP-1) strongly present on the adipocyte surface. Methods: Previously, irreversible MAO inhibitors have been reported to limit food intake and/or fat extension in rodents; however, their use for the treatment of depressed patients has not revealed a clear anti-obesity action. Semicarbazide and other molecules inhibiting SSAO/VAP-1 also reduce adiposity in obese rodents. Results: Recently, a LOX inhibitor and a subtype-selective MAO inhibitor have been shown to limit fattening in high-fat diet-fed rats. Phenelzine, which inhibits MAO and AOC, limits adipogenesis in cultured preadipocytes and impairs lipogenesis in mature adipocytes. When tested in rats or mice, phenelzine reduces food intake and/or fat accumulation without cardiac adverse effects. Novel amine oxidase inhibitors have been recently characterized in a quest for promising anti-inflammatory or anti-cancer approaches; however, their capacity to mitigate obesity has not been studied so far. Conclusions: The present review of the diverse effects of amine oxidase inhibitors impairing adipocyte differentiation or limiting excessive fat accumulation indicates that further studies are needed to reveal their potential anti-obesity properties.

PKG1α oxidation negatively regulates food seeking behaviour and reward

Genes that are highly conserved in food seeking behaviour, such as protein kinase G (PKG), are of interest because of their potential role in the global obesity epidemic. PKG1α can be activated by binding of cyclic guanosine monophosphate (cGMP) or oxidant-induced interprotein disulfide bond formation between the two subunits of this homodimeric kinase. PKG1α activation by cGMP plays a role in reward and addiction through its actions in the ventral tegmental area (VTA) of the brain. ‘Redox dead’ C42S PKG1α knock-in (KI) mice, which are fully deficient in oxidant-induced disulfide-PKG1α formation, display increased food seeking and reward behaviour compared to wild-type (WT) littermates. Rewarding monoamines such as dopamine, which are released during feeding, are metabolised by monoamine oxidase to generate hydrogen peroxide that was shown to mediate PKG1α oxidation. Indeed, inhibition of monoamine oxidase, which prevents it producing hydrogen peroxide, attenuated PKG1α oxidation and increased sucrose preference in WT, but not KI mice. The deficient reward phenotype of the KI mice was rescued by expressing WT kinase that can form the disulfide state in the VTA using an adeno-associated virus, consistent with PKG1α oxidation providing a break on feeding behaviour. In conclusion, disulfide-PKG1α in VTA neurons acts as a negative regulator of feeding and therefore may provide a novel therapeutic target for obesity.

Medications that cause weight gain and alternatives in Canada: a narrative review

BACKGROUND

The cause of the obesity epidemic is multifactorial, but may, in part, be related to medication-induced weight gain. While clinicians may strive to do their best to select pharmacotherapy(ies) that has the least negative impact on weight, the literature regarding the weight effects of medication is often limited and devoid of alternative therapies.

RESULTS

Antipsychotics, antidepressants, antihyperglycemics, antihypertensives and corticosteroids all contain medications that were associated with significant weight gain. However, there are several medication alternatives within the majority of these classes associated with weight neutral or even weight loss effects. Further, while not all of the classes of medication examined in this review have weight-favorable alternatives, there exist many other tools to mitigate weight gain associated with medication use, such as changes in dosing, medication delivery or the use of adjunctive therapies.

CONCLUSION

Medication-induced weight gain can be frustrating for both the patient and the clinician. As the use of pharmaceuticals continues to increase, it is pertinent for clinicians to consider the weight effects of medications prior to prescribing or in the course of treatment. In the case where it is not feasible to make changes to medication, adjunctive therapies should be considered.

Body fat reduction without cardiovascular changes in mice after oral treatment with the MAO inhibitor phenelzine

BACKGROUND AND PURPOSE

Phenelzine is an antidepressant drug known to increase the risk of hypertensive crisis when dietary tyramine is not restricted. However, this MAO inhibitor inhibits other enzymes not limited to the nervous system. Here we investigated if its antiadipogenic and antilipogenic effects in cultured adipocytes could contribute to decreased body fat in vivo, without unwanted hypertensive or cardiovascular effects.

EXPERIMENTAL APPROACH

Mice were fed a standard chow and given 0.028% phenelzine in drinking water for 12 weeks. Body composition was determined by NMR. Cardiovascular dysfunction was assessed by heart rate variability analyses and by evaluation of cardiac oxidative stress markers. MAO activity, hydrogen peroxide release and triacylglycerol turnover were assayed in white adipose tissue (WAT), alongside determination of glucose and lipid circulating levels.

KEY RESULTS

Phenelzine-treated mice exhibited lower body fat content, subcutaneous WAT mass and lipid content in skeletal muscles than control, without decreased body weight gain or food consumption. A modest alteration of cardiac sympathovagal balance occurred without depressed aconitase activity. In WAT, phenelzine impaired the lipogenic but not the antilipolytic actions of insulin, MAO activity and hydrogen peroxide release. Phenelzine treatment lowered non-fasting blood glucose and phosphoenolpyruvate carboxykinase expression. In vitro, high doses of phenelzine decreased both lipolytic and lipogenic responses in mouse adipocytes.

CONCLUSION AND IMPLICATIONS

As phenelzine reduced body fat content without affecting cardiovascular function in mice, it may be of benefit in the treatment of obesity-associated complications, with the precautions of use recommended for antidepressant therapy.

Tranylcypromine in mind (Part II): Review of clinical pharmacology and meta-analysis of controlled studies in depression

It has been over 50 years since a review has focused exclusively on the monoamine oxidase (MAO) inhibitor tranylcypromine (TCP). A new review has therefore been conducted for TCP in two parts which are written to be read preferably in close conjunction: part I - pharmacodynamics, pharmacokinetics, drug interactions, toxicology; and part II - clinical studies with meta-analysis of controlled studies in depression, practice of TCP treatment, place in therapy. The irreversible and nonselective MAO-A/B inhibitor TCP has been confirmed as an efficacious and safe antidepressant drug. For the first time, a meta-analysis of controlled clinical trials in depression demonstrated that TCP is superior to placebo (pooled logOR=0.509, 95%CI=0.026 to 0.993, 4 studies) and equal to other antidepressants (pooled logOR=0.208, 95%CI=-0.128 to 0.544, 10 studies). In treatment resistant depression (TRD) after tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs), TCP was superior to placebo (logOR=2.826, 95%CI=1.494 to 4.158, one study) and non-established antidepressants (pooled logOR=1.976, 95%CI=0.907 to 3.045, 4 studies), and was equal to other MAO inhibitors and an antidepressant combination (pooled logOR=-0.366, 95%CI=-0.869 to 0.137, 4 studies). Controlled studies revealed that TCP might provide a special advantage in the treatment of atypical depression, which was supported by a recent PET study of MAO-A activity in brain. However, TCP treatment remains beset with the need for a mandatory tyramine-restricted diet and is therefore limited to use as a third-line antidepressant according to recent treatment algorithms and guidelines for depression treatment. On the other hand, the effort needed to maintain a tyramine-restricted diet may have been overestimated in the perception of both doctors and patients, which may have led to relative underuse of TCP. Interaction with serotonergic drugs bears the risk of severe serotonin toxicity (SST) and combination with indirect sympathomimetic drugs may result in hypertensive crisis which both adds to the risks of TCP. At the same time, TCP has low to no risks of central anticholinergic, sedative, cardiac conduction, body weight, hemostatic effects, or pharmacokinetic drug interactions. Neuroprotection by MAO inhibitors due to reduced oxidative stress is becoming increasingly studied. Taken together, TCP is being increasingly recognized as an important option in systematic treatment approaches for patients suffering from severe courses of depression, such as TRD and atypical depression, by offering a MAO-related pathophysiological rationale.

Metabolic Effects of Antidepressant Treatment

INTRODUCTION

This study aimed to investigate body measurements, glucose-insulin metabolism, and lipid profile in patients with anxiety and depressive symptoms and also the effects of antidepressant drugs on these metabolic parameters.

METHODS

The study included 40 outpatients and 32 healthy controls. The patients received antidepressant treatment (sertraline, escitalopram, fluoxetine, and venlafaxine) for 8 weeks. Body measurements were performed, and lipid, fasting blood glucose, and insulin levels were measured before and after treatment in patients and once in healthy controls. Insulin resistance was evaluated using the homeostasis model assessment (HOMA) index.

RESULTS

Body mass index was higher in patients than in healthy controls, and there was no change in patients after treatment. In patients, high-density lipoprotein (HDL) cholesterol levels increased owing to the antidepressant treatment. Insulin level and HOMA index had a tendency to decrease with the treatment in patients and were similar to those of healthy controls before the treatment; however, they became lower than those of healthy controls after the treatment. There was an increase in waist circumference and total and HDL cholesterol levels, whereas there was a decrease in fasting blood glucose levels with treatment in patients using escitalopram. There was no change in body measurements and biochemical and hormone values in patients using fluoxetine, sertraline, and venlafaxine. There was an increase in weight, body mass index, and waist circumference after treatment in patients with depression; however, there was no change in patients with anxiety.

CONCLUSION

In patients with psychiatric disorders having anxiety and depressive symptoms, metabolic changes independent of drugs and the metabolic effects of drugs are present.

Effect of Ginkgo biloba extract on lipopolysaccharide-induced anhedonic depressive-like behavior in male rats

The peripheral administration of lipopolysaccharide (LPS) induces depressive-like behavior. Anhedonia is a core symptom of depression, defined as a loss of the capacity to experience pleasure. The present study used the sucrose preference test to investigate the influence of Ginkgo biloba extract (EGb 761) on LPS-induced anhedonia in male rats. The animals were randomly divided into four groups: (I) vehicle + saline, (II) vehicle + LPS, (III) EGb 761 + saline, and (IV) EGb 761 + LPS. Saline or LPS (100 µg/kg) was administered intraperitoneally 2 h before the sucrose preference test. Sucrose consumption was recorded 2, 4, 6, 13, and 24 h after 100 µg/kg of LPS or saline injection in the dark phase of the light/dark cycle. Dopamine and serotonin levels in the nucleus accumbens were measured. Our results indicated that the vehicle + LPS group exhibited a significant decrease in sucrose intake compared with the vehicle + saline group. The EGb 761 + LPS group showed more sucrose and food consumption than the vehicle + LPS group. Additionally, compared with the EGb 761 + LPS group, the vehicle + LPS group had less dopamine levels in the nucleus accumbens. Treatment with EGb 761 had no effect on water intake. Our results suggest that EGb 761 may be useful for reducing anhedonic depressive-like behavior.

Changes in body weight and psychotropic drugs: a systematic synthesis of the literature

INTRODUCTION

Psychotropic medication use is associated with weight gain. While there are studies and reviews comparing weight gain for psychotropics within some classes, clinicians frequently use drugs from different classes to treat psychiatric disorders.

OBJECTIVE

To undertake a systematic review of all classes of psychotropics to provide an all encompassing evidence-based tool that would allow clinicians to determine the risks of weight gain in making both intra-class and interclass choices of psychotropics.

METHODOLOGY AND RESULTS

We developed a novel hierarchical search strategy that made use of systematic reviews that were already available. When such evidence was not available we went on to evaluate randomly controlled trials, followed by cohort and other clinical trials, narrative reviews, and, where necessary, clinical opinion and anecdotal evidence. The data from the publication with the highest level of evidence based on our hierarchical classification was presented. Recommendations from an expert panel supplemented the evidence used to rank these drugs within their respective classes. Approximately 9500 articles were identified in our literature search of which 666 citations were retrieved. We were able to rank most of the psychotropics based on the available evidence and recommendations from subject matter experts. There were few discrepancies between published evidence and the expert panel in ranking these drugs.

CONCLUSION

Potential for weight gain is an important consideration in choice of any psychotropic. This tool will help clinicians select psychotropics on a case-by-case basis in order to minimize the impact of weight gain when making both intra-class and interclass choices.

Obesity and psychotropics

Weight gain is on the rise in the United States as is the diagnosis and treatment of mental disorders. These two phenomena are distinctly separate but tend to overlap in that most psychotropic agents approved for use in the United States are associated with the potential to induce weight gain. Metabolic disorders such as diabetes, hypercholesterolemia, and hypertension are also on the rise and often associated with weight gain and clearly associated with certain psychotropic medications. This article serves to provide a succinct review regarding the epidemiology, etiology, and treatment options for psychotropic-induced obesity.

MAO-inhibitors in Parkinson's Disease

Monoamine oxidase inhibitors (MAO-I) belong to the earliest drugs tried in Parkinson's disease (PD). They have been used with or without levodopa (L-DOPA). Non-selective MAO-I due to their side-effect/adverse reaction profile, like tranylcypromine have limited use in the treatment of depression in PD, while selective, reversible MAO-A inhibitors are recommended due to their easier clinical handling. For the treatment of akinesia and motor fluctuations selective irreversible MAO-B inhibitors selegiline and rasagiline are recommended. They are safe and well tolerated at the recommended daily doses. Their main differences are related to (1) metabolism, (2) interaction with CYP-enzymes and (3) quantitative properties at the molecular biological/genetic level. Rasagiline is more potent in clinical practise and has a hypothesis driven more favourable side effect/adverse reaction profile due to its metabolism to aminoindan. Both selegiline and rasagiline have a neuroprotective and neurorestaurative potential. A head-to head clinical trial would be of utmost interest from both the clinical outcome and a hypothesis-driven point of view. Selegiline is available as tablet and melting tablet for PD and as transdermal selegiline for depression, while rasagiline is marketed as tablet for PD. In general, the clinical use of MAO-I nowadays is underestimated. There should be more efforts to evaluate their clinical potency as antidepressants and antidementive drugs in addition to the final proof of their disease-modifying potential. In line with this are recent innovative developments of MAO-I plus inhibition of acetylcholine esterase for Alzheimer's disease as well as combined MAO-I and iron chelation for PD.

Weight gain, obesity, and psychotropic prescribing

A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. There is much speculation about the prevalence of weight gain and the degree of weight gain during acute and longitudinal treatment with these agents. There is newer literature looking at the etiology of this weight gain and the potential treatments being used to alleviate this side effect. The authors undertook a comprehensive literature review in order to present epidemiology, etiology, and treatment options of weight gain associated with antipsychotics, mood stabilizers, and antidepressants.

The association between conventional antidepressants and the metabolic syndrome: a review of the evidence and clinical implications

Major depressive disorder is a prevalent recurrent medical syndrome associated with inter-episodic dysfunction. The metabolic syndrome is comprised of several established risk factors for cardiovascular disease (i.e. abdominal obesity, dyslipidaemia, dysglycaemia and hypertension). The criterion items of the metabolic syndrome collectively represent a multi-dimensional risk factor for cardiovascular disease and type 2 diabetes mellitus. Extant evidence indicates that both major depressive disorder and the metabolic syndrome, albeit distinct, often co-occur and are possibly subserved by overlapping pathophysiology and causative mechanisms. Conventional antidepressants exert variable effects on constituent elements of the metabolic syndrome, inviting the need for careful consideration prior to treatment selection and sequencing. Initiating and maintaining antidepressant therapy should include routine surveillance for clinical and/or biochemical evidence suggestive of the metabolic syndrome.

Drugs and nutrition: how side effects can influence nutritional intake

There are many factors that can influence nutritional intake. Food availability, physical capability, appetite, presence of gastrointestinal symptoms and perception of food are examples. Drug therapy can negatively influence nutritional intake through their effect on these factors, predominantly due to side effects. This review aims to give a brief overview of each of these factors and how drug therapy can affect them. Specific examples are given for each section and an indication of the impact on nutritional status. This article aims to assist the clinician in the identification of the effects of drug therapy on nutritional intake and provides advice on appropriate intervention. A drug history and side effect review should form an integral part of nutritional assessment. Early identification and effective therapeutic use of alternative drug therapy can also positively influence nutritional intake.

Desvenlafaxine and weight change in major depressive disorder

OBJECTIVE

To characterize weight change during short- and longer-term treatment with desvenlafaxine (administered as desvenlafaxine succinate) for major depressive disorder (MDD).

METHOD

Data from 9 short-term, double-blind, placebo-controlled studies and 1 longer-term relapse-prevention trial conducted between September 2002 and January 2007 were analyzed. Adult outpatients with a primary diagnosis of MDD using criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition received fixed- or flexible-dose desvenlafaxine or placebo for 8 weeks in the short-term studies. In the longer-term study, responders to 12 weeks of open-label desvenlafaxine treatment were randomly assigned to double-blind treatment with desvenlafaxine or placebo for 6 months. Mean weight changes and incidence of potentially clinically important changes were evaluated.

RESULTS

In the short-term studies (desvenlafaxine: n = 1,834; placebo: n = 1,116), mean decreases in weight associated with desvenlafaxine were small but statistically significant compared with baseline (P < .05) and with placebo (final evaluation: -0.82 kg desvenlafaxine vs + 0.05 kg placebo; P < .001). Likewise, during the 12-week, open-label phase of the relapse-prevention study (n = 594), a small but statistically significant mean decrease in weight from baseline (-0.8 kg; P < .001) occurred. Small mean increases in weight (< 1 kg) were observed with both desvenlafaxine (n = 190) and placebo (n = 185) throughout the relapse-prevention phase, with no statistical difference between desvenlafaxine- and placebo-treated patients at the final evaluation. Less than 1% of desvenlafaxine-treated patients experienced a clinically meaningful weight change.

CONCLUSIONS

Desvenlafaxine was not associated with clinically significant weight change during short- or longer-term treatment.

Neuropsychiatric disorders at the presentation of type 2 diabetes mellitus in children

OBJECTIVES

To estimate the frequency of neuropsychiatric disease (NPD) in an urban pediatric type 2 diabetes mellitus (T2DM) population, to compare demographic characteristics of affected patients with those unaffected with NPD, and to determine the frequency of psychotropic medication treatment.

STUDY DESIGN

Retrospective chart review of patients with T2DM at the Children's Hospital of Philadelphia.

RESULTS

Of 237 patients with T2DM, 46 (19.4%) were found to have NPD at the presentation of diabetes. Diagnoses by report included depression, attention-deficit hyperactivity disorder (ADHD), neurodevelopmental disorders, schizophrenia, and bipolar disorder. Those affected were 63% females and 37% males, with a mean age of 14.6 yr and body mass index (BMI) of 34.3 kg/m(2) at diagnosis of T2DM. Patients were 79% African American, 13% Caucasian, 4.3% Hispanic, and 4.3% Asian. There were no statistically significant differences in demographic characteristics or BMI between those affected and unaffected with NPD. Twenty-nine patients (63%) were on psychotropic medication and were prescribed 58 medications, most commonly mood stabilizers (n = 20) and atypical antipsychotics (n = 17).

CONCLUSIONS

Our data reveal a high frequency of NPD among pediatric patients with T2DM at presentation to a tertiary care, urban medical center. Many affected patients are receiving psychotropic medication. These data have implications for screening regimens for pediatric populations at high risk for T2DM and for therapeutic interventions, including lifestyle measures.

Psychiatric medication-induced obesity: treatment options

A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. The authors undertook a comprehensive literature review in order to provide a better understanding of novel treatment options in regards to alleviating weight gained by use of antidepressants, antipsychotics, and mood stabilizers. There are no agents for management of this weight gain approved by the Food and Drug Administration (FDA), and existing studies on options are mainly uncontrolled, small-scale projects with limited power to produce coherent conclusions. There is a clear need for larger studies on existing options, and future psychotropics without these side-effects are currently in the pipeline.

Psychiatric medication-induced obesity: a review

A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. There is much speculation about the prevalence of weight gain and the degree of weight gain during acute and longitudinal treatment with these agents. There is newer literature looking at the aetiology of this weight gain and the potential treatments being used to alleviate this side-effect. We found solid evidence that weight gain is often associated with the mood stabilizers, and antipsychotics and antidepressants. Only few weight neutral or weight loss producing psychotropics are available, and weight gain, outside of an immediate side-effect, may generate secondary side-effects and medical comorbidity. Weight gain may cause hypertension, diabetes, osteoarthritis, sedentary lifestyle, coronary artery disease, etc. Given the likelihood of inducing weight gain with psychotropic medications and the longitudinal impact on physical health, a thorough literature review is warranted to determine the epidemiology, aetiology and treatment options of psychotropic-induced weight gain.

Epidemiology, implications and mechanisms underlying drug-induced weight gain in psychiatric patients

Body weight gain frequently occurs during drug treatment of psychiatric disorders and is often accompanied by increased appetite or food craving. While occurrence and time course of this side effect are difficult to predict, it ultimately results in obesity and the morbidity associated therewith in a substantial part of patients, often causing them to discontinue treatment even if it is effective. This paper reviews the available epidemiological data on the frequency and extent of weight gain associated with antidepressant, mood-stabilizing, and antipsychotic treatment. Possible underlying pathomechanisms are discussed with special attention to central nervous control of appetite including the role of leptin and the tumor necrosis factor system. Metabolic alterations induced by drug treatment such as type 2 diabetes mellitus and the metabolic syndrome are also considered. Weight gain appears to be most prominent in patients treated with some of the second generation antipsychotic drugs and with some mood stabilizers. Marked weight gain also frequently occurs during treatment with most tricyclic antidepressants, while conventional antipsychotics typically induce only slight to moderate weight gain. Serotonin reuptake inhibitors may induce weight loss during the first few weeks, but some of them induce weight gain during long-term treatment. Several antidepressant and antipsychotic drugs are identified which reliably do not cause weight gain or even reduce weight. Based on these insights, countermeasures to manage drug-induced weight gain are suggested.

'Why getting fat, Doc?' Weight gain and psychotropic medications

OBJECTIVES

Weight gain associated with the use of psychotropic medications is a common clinical problem that is of particular importance because of its effects on the general health of psychiatric patients and their compliance with treatment. This paper aims to explore this issue and discuss the mechanisms of weight gain and methods of prevention.

METHOD

A literature review (Index Medicus/Medline) was carried out as well as a review of other relevant papers and data known to the authors.

RESULTS

Significant weight gain may result in considerable morbidity. The majority of psychotropic medications are associated with weight gain, however, the mechanisms of weight gain are often complex and poorly understood.

CONCLUSION

Clinically, weight gain can be anticipated and often managed with some success in the majority of psychiatric patients with simple but relatively effective measures. It is important for clinicians to be aware of this common clinical problem and educate patients from the outset, monitoring them regularly and intervening when necessary.