The Link Between Antidepressants and Weight Gain

A study conducted by researchers in the School of Population Health and Environmental Sciences found a 21% increase in patients who experienced weight gain after taking prescribed antidepressant medication compared to patients not taking these medications. Furthermore, the risk of weight gain or obesity increased by 29% after prolonged use of said antidepressants for where treatment was over the course of 2-3 years.

Another study showed similar results where 268 patients in a General Practice (GP) who were being treated with antidepressants and weight gain were analysed. Results showed that patients who were on long-term antidepressants had increased weight gain compared to at the start of treatment.

A study conducted in the United States of America analysed data from 22,610 adults who were being treated in clinics in New England for depression and other related mental health disorders hence started treatment with anti-depressants. After 12 months of continued treatment, patients showed significant weight gain compared to the start of the treatment.

Furthermore, studies show that weight gain is one of the main reasons that compliance with taking antidepressants reduces drastically and treatment is most often discontinued by patients due to this particular side effect. This increases the chances of a patient relapsing and worsening symptoms of depression.

Data from the health survey of England shows that prevalence of obesity increased from 23% to 26% between 2004 and 2014 and that the increased use of antidepressants to treat certain disorders is contributing to the high incidence rates of obesity. Both weight gain and obesity are currently health problems that need to be addressed in the UK and are considered a public health concern. Once an individual reaches obesity, it becomes difficult to lose weight and opens up a myriad of other health problems causing further burden on the healthcare system.

Why Antidepressants May Affect Weight

Anti-depressants are medications normally prescribed for various disorders affecting the mental, emotional and physical state of an individual. These range from illnesses such as depression, anxiety disorder, post-traumatic stress disorder, obsessive compulsive disorder and many others. The focus will be on major depressive disorder (MDD) for the purpose of this article.

Major depressive disorder (MDD) is considered one of the most widespread psychiatric disorders affecting more than 200 million people around the world. It is a disease of the mind which manifests in different ways and causes significant harm to an individual and reduces their quality of life. Individuals with MDD present with loss of mood, loss of interest in activities they previously enjoyed, suicidal ideation, self-harming tendencies, and so on.

MDD is normally treated via a combined effort involving cognitive behavioral therapy (CBT) and pharmacological intervention through the use of antidepressant medications. However, sometimes, CBT is not always beneficial to some individuals and may require treatment with stronger antidepressants instead.

Antidepressants can have a positive effect on an individual’s mental and thereby physical health. However, common questions from patients tend to inquire about potential side effects such as can antidepressants cause weight gain? And unfortunately, one of the major side effects of antidepressants is weight gain which can change a person’s metabolism and overtime lead to issues with weight management.

Serotonin is a hormone that is extremely important in signaling satiety (fullness) to the brain via receptors. However, using SSRIs (a class of antidepressants) for a long period of time desensitises the receptors which normally regulate serotonin signalling therefore the satiety signal does not reach the brain as efficiently. Individuals will therefore continue eating because they can no longer feel satiety as the appropriate signaling mechanisms are no longer in place.

SSRI and Weight Gain – A Comparison of Common Medications

Selective serotonin reuptake inhibitors (SSRIs) are a well known class of antidepressants used to treat several types of psychiatric disorders such as major depressive disorder, obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), anxiety disorders and so on.

These work by strongly inhibiting (blocking) serotonin transporter (SERT) so serotonin does not get easily removed from the synaptic cleft and its effects can continue for longer. Serotonin is important for numerous reasons especially to regulate mood, motivation and reduce anxiety therefore, all of these effects are enhanced over time, symptoms of depression start to lessen. The individual can hereafter manage their lives better due to improved mood, an increase in appetite and general feelings of normalcy and so on.

The following table highlights SSRIs and weight gain comparison. It shows the mechanism of action and how likely an individual will deal with the side effect of weight gain with different SSRIs ranging from high risk medications to low risk medications for weight gain:

Based on the table above, several antidepressant’s side effects show weight gain as a major side effect especially in SSRIs however, some SSRIs do this more than others. Therefore if antidepressant and weight gain in the UK is a major concern for an individual then it is recommended to opt for a low risk medication such as Fluoxetine compared to Paroxetine as shown above. Head over to Meds for Less to find out more about these medications. Whilst we unfortunately do not stock SSRIs, we do stock other anxiety depression medications and other General Health Medicines.

However, as with most SSRI medications, weight gain is possible if the SSRIs are used over a long period of time. Hence, these concerns should be discussed with a healthcare professional to find the best course of treatment that will suit the individual’s needs.

Do All Depression Medications Cause Weight Changes?

There is a series of anti-depressant medications that have shown limited to no changes in weight gain (weight neutral) or shown signs of weight loss and these are detailed below:

Antidepressants and Weight Gain in the UK – What Patients Should Know

Major Depressive Disorder (MDD) has an impact not only on the mental state of the individual but has widespread effects in their daily life which damages the individual’s relationship with oneself and also the people around them. MDD is caused by a multitude of factors and cannot be attributed to one single cause. It is known to stem from a mix of genetic, physiological, biological and environmental factors.

In order to be diagnosed with MDD, an individual needs to fulfil the criteria set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The individual affected needs to have experienced symptoms of depression lasting for more than two weeks where at least five characteristics are present. These are: feelings of depression, loss of interest in daily/pleasurable activities, difficulty sleeping (insomnia), noticeable fluctuations in body weight, loss of energy, feelings of hopelessness, negative internal dialogue and so on.

These symptoms can also cause several metabolic changes in the body. Feelings of depression tend to increase appetite in some individuals also known as ‘emotional eating’. This is where a person with depressive episodes may turn to food and satisfy their needs and cravings to get a hit of dopamine – a neurotransmitter which is reduced in individuals with depression. Dopamine is essential for mood, rewarding behavior and for motivation.

Treatment with antidepressants can help with symptoms of depression. It can regulate levels of serotonin in the body and help with mood, motivating behaviors and enable a positive mindset. However, as with all medications, antidepressants can cause weight gain which may not be ideal for some individuals.

Long-term use of antidepressants can desensitise the receptors which are targeted by these drugs and decrease the effects of  key signaling mechanisms. This increases appetite and reduces feelings of satiety therefore increasing weight. This leads to an overconsumption of food rich in calories and craving sugary snacks due to inhibition of histamine receptors.  Patients may also experience sedative effects with antidepressants which may further exacerbate weight gain due to an increase in appetite. Some antidepressants may also create hormonal imbalances especially in women through increase in production of prolactin causing irregularities in menstruation and also sexual dysfunction.

Patients should be aware of the potential risks with antidepressants especially if weight gain is a major concern. Patients should be advised to speak to their healthcare providers to look at the pros and cons of specific antidepressant drug classes and only then curate a treatment plan with the most minimal side effects. However, if the low risk antidepressants do not work, then it may be necessary to take antidepressants and look into other effective strategies for weight management which may be a mix of diet, lifestyle factors and potentially CBT.

Managing Weight While Taking Antidepressants

Managing weight whilst taking antidepressants is crucial to maintaining good health over the long term and minimising risks of co-morbidities such as Type 2 Diabetes, cardiovascular problems such as Coronary heart disease and so on.

Furthermore, studies show that weight gain reduces compliance with taking antidepressants and treatment is most often discontinued by patients due to this particular side effect. This increases the chances of a patient relapsing and worsening symptoms of depression.

Therefore, weight management is key when treating psychiatric disorders with antidepressants and can be achieved in several ways as shown below:

• Eating smaller meals but eating more often to allow food to digest throughout the day instead of having big meals at certain times and overloading the digestive system
• Increasing protein intake as protein is key for body functions and a good source of energy
• Decreasing the amount of white carbohydrates which are high in sugar for eg: white bread, pasta, white rice and instead opting for wholemeal versions and increasing fiber intake.
• Try to avoid having large meals too close to sleeping to allow the body to digest food efficiently and not disrupt sleep as sleep is incredibly important to improve symptoms of depression
• Consult with a nutritionist to form a food plan which is customised to your needs and requirements.
• Avoid sugary or energy drinks which are high in sugar content.
• Exercise – this is key to ensuring the body stays fit and active and is also good for the mind. Try to engage in activities at least 2-3 times a week. This can range from walking, running, swimming, trying a new sport, or any other hobbies which involve regular movement of the body.

Speak to your healthcare provider who will assist you in tailoring a customised diet and exercise plan and help you achieve your goals for weight management.

When to Talk to Your Doctor About Weight Changes

Talk to your doctor if you or anyone you know who is on antidepressant medications notices the following changes:

• Drastic changes in weight which could be either weight loss or weight gain and is unintentional.
• Clothes have started to feel too tight or too loose which is abnormal for you.
• If your weight is starting to affect your health causing blood pressure problems, increasing sugar levels in the body (could lead to T2 diabetes if not managed), making it difficult to do every day tasks.
• If your weight is affecting the way you view yourself and has taken a toll on your self-esteem and mood.
• If you believe the changes in weight have become more noticeable since taking the antidepressants or any other medication.
• If you are dieting and exercising and are still unable to manage your weight as there may be other underlying causes for weight gain which need investigating.