Heart Disease, Olanzapine and Mental Health

by Leigh on September 5, 2012

olanzapine weight gain heart disease

Heart disease is the major cause of death in patients with mental health issues – could weight gain from olanzapine be contributing?

A new study suggests that a drug used to treat schizophrenia and bipolar disorder could be connected to increased appetite, unhealthy weight gain, heart disease and resulting fatal heart attacks. Olanzapine is an atypical antipsychotic medication that has been found to alter the response of specific food reward areas of the brain. This new finding could explain why one of the most commonly reported side-effects of olanzapine is significant weight gain.

Olanzapine and Brain Activity

In the study, twenty-five healthy volunteers were monitored, against controls, for brain activity whilst being given a week of olanzapine treatment. The researchers found that increased activity occurred in the inferior frontal cortex, striatum, and anterior cingulate cortex in anticipation of receiving food. Whilst eating the food the subjects also showed enhanced activity in the caudate and putamen areas of the brain. A decrease in reward responsivity in the lateral orbital frontal cortex was also noted; this is an area of the brain associated with inhibitory control of food intake.

Olanzapine, Weight Gain and Heart Health

What this all means is that it appears that olanzapine may enhance the anticipatory desire for food, make it feel more rewarding and reduce feelings of satiation and thus perpetuate appetite and consumption. Such changes in eating patterns and response to food are extremely likely to lead to increased consumption and significant weight gain, which may then affect metabolic parameters connected to heart health.

Heart Disease and Mental Health

The research was carried out at the Department of Psychiatry at Washington University in St. Louis, Missouri, with lead author Jose Mathews, MD., noting that the findings could help in creating new drugs to address unhealthy eating patterns. Whilst weight gain and obesity are not always a direct route to heart attacks the likelihood of fatal myocardial infarction, stroke, or other cardiovascular event is increased with unhealthy weight gain. Heart disease is the leading cause of death amongst those with mental illness, with many medications thought to contribute to this problem. As well as affecting the risk of heart disease, unwanted weight gain in those with mental illness could actually contribute to the patients’ suffering through reduced self-confidence and self-esteem.

Study Details

Those studied during this research into the connected between olanzapine and weight gain had a Body Mass Index of 25.78 and were around 27.5 years old. Just over half of the participants were male, and all those in the treatment arm of the study received 5-6mg of olanzapine for a week whilst having functional magnetic resonance imaging (fMRI) scans to monitor neural activity. Such scans were performed before treatment began and whilst receiving treatment and the food rewards were chocolate milk and/or tomato juice. A Patient Rated Inventory of Side Effects and the Three-Factor Eating Questionnaire were used during the study to assess patients’ own feelings regarding their changing appetites and food responses.

Olanzapine Side-Effects

Those receiving olanzapine gained an average of 1.1kg during the week of treatment, which worked out to a statistically significant gain in weight and increase in BMI. Overall food consumption significantly increased as did disinhibited eating but no immediate significant increases in blood pressure or heart rate were found. Two participants dropped out due to intolerable side-effects, including somnolence and fatigue, and headaches. Other olanzapine side-effects noted by subjects included excess sleep, reduced energy, dry mouth and dizziness.

Antipsychotics and Heart Health

The researchers hope that further studies are now undertaken comparing olanzapine with other antipsychotic agents in regards to weight gain and disinhibition of eating. They also note the potential for changes in food reward responses due to adverse interactions when olanzapine is prescribed for patients with ongoing substance abuse issues. With heart disease the major cause of death in patients with mental health issues, understanding the full range of effects of antipsychotic medications could help save lives. Establishing the connection between olanzapine, significant weight gain and heart disease could help in devising ways to reduce complications for those being treated for schizophrenia and bipolar disorder.


Mathews, J., Newcomer, J.W., Neural Correlates of Weight Gain With Olanzapine, Arch Gen Psychiatry. Published online August 6, 2012.

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