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Pollution and antidepressants: The flavour of medications in our tasteless waters

In 1962, marine biologist Rachel Carson reported in her book Silent Spring on the environmental effects caused by the indiscriminate use of pesticides. Her work and dedication inspired many scientists and environmental activists.

More recently, the environmental activist on climate change, Greta Thunberg, has mobilised children all around the world for: ‘school strike for climate (Swedish: skolstrejk för klimatet)’. Her mottos are “No one is too small to make a difference” and “United behind science”.

The voices of many other activists and scientists have been heard.

People with busy everyday lives start to think about their impact on the environment. One of them is a patient of mine who has suffered from severe depression for many years. The antidepressant treatment helped her to enjoy life to its fullest.

One day, she asked me a question: “Is my medication environmentally friendly?”. The answer?! A puzzled faced, as I murmured “I don’t know”.

Photography from European pharmaceutical review


“Every problem cries in its own language.” (Tomas Tranströmer, About History 1966). In the same way, we see this with the effects of human activity on the environment.

Sometimes we hear the loudest wails — enraged forest fires, devasting floods.

Other times, we hear it as whimpers, present a little bit every day, and we try to find small solutions.

The European Medicines Agency acknowledged the environmental risk of our medications, and ever since 2006 it requires an environmental risk assessment for the approval of new pharmaceuticals.

Many medications out there were approved before 2006, and there is a lack of research on their environmental risk. We do not know how plants, animals, bacterias (e.g., aquatic environment), or other elements of biodiversity, are affected by long-term and low-level exposure to pharmaceuticals, including medication for psychiatric use.

Environmental risk assessments need to be improved, and there are several recommendations for the future, such as requiring an environmental risk assessment for pharmaceutical products put on the market before 2006, and to increase transparency between environmental risk assessment and manufacturing sites.

What we know so far is that psychiatric medication, other pharmacological compounds, and even drugs of abuse (such as cocaine, ketamine and methamphetamine) are present everywhere in our environment.

Extremely small amounts can be measured in drinking water and are considered not harmful to humans. However, the effects on other species are largely unknown, and more research is needed.

According to the European Medicines Agency, there are a few pathways on how pharmaceutical products disseminate in the environment.

Adapted from the European Medicines Agency


What do we know about medication for psychiatric use and its environmental risk?

Most pharmaceutical companies report on the impact of new psychiatric medication regarding the effects on the growth, mortality, and reproduction of species.

Although these pharmaceuticals alter wildlife behaviour, few studies are reported on behavioural changes. Moreover, the European Medicines Agency does not currently require studies on behavioural changes as part of the environmental risk assessment.

What will the concentration of antidepressants in drinking water in Stockholm, Sweden (Photograph 1) be, compared with drinking water on Itsukushima (Deer Island), Japan (Photograph 2)?

Photograph 1: by Mikael Stenberg on Unsplash

I am wondering if someone can say how common depression or anxiety is in an area by measuring the concentration of medication in drinking water. It is probably not that simple to answer this question as there is a long way to go from seeking care to receiving antidepressant medication.

View fullsizePhotograph 2: courtesy of Kristian H. Reveles Jensen

Antidepressant medications are usually prescribed for the treatment of depression, anxiety, or chronic pain.

Photograph 2: courtesy of Kristian H. Reveles Jensen

One of the common behavioural effects of antidepressants in humans is reducing impulsivity, while a common side effect is decreasing libido.

Fluoxetine and citalopram are two of the most used antidepressants in Europe and USA and have consistently been reported in surface water and in very small amounts in our drinking water. Experimental studies suggest that fluoxetine can cause developmental delays in a species of amphibians (like frogs).

Furthermore, fluoxetine can alter the behaviour of starlings and of different species of fish. In fish, antidepressants(fluoxetine, sertraline, venlafaxine, citalopram and bupropion) could also reduce aggressive behaviour and affect the feeding and reproductive behaviours.

Other potent and widely used anxiolytics — medications which help reduce anxiety — include benzodiazepines such as oxazepam and diazepam. These medications persist in wastewater and are resistant to any breakdown by sunlight and air (known as the photodegradation process). This means that these medications remain, though in relatively low concentrations, in the aquatic environment.

Studies from Sweden reported that oxazepam, a widely used benzodiazepine, increases the migration pattern of salmon and alters the behaviour and feeding rates of wild European perch, another type of fish.

What can be done by patients and clinicians?

The Swedish Prescribing Guide have some tips to minimise the environmental impact:

1. Prescribe a small number of tablets when a patient tries a new medication

2. The patient information leaflet of many / most of the psychopharmacological drugs contains information on environmental risks. Doctors also need to create a routine in informing the patient on this issue as I am quite sure that in time clinicians will receive this question a lot more often.

3. Patients should be informed that no medication should be discarded among household waste or flushed in the toilet.

4. Leftover drugs and pharmaceutical packing (such as aerosol containers, powder inhalers, vials and ampoules, packaging containing infusion fluids, depot injections, depot patches, vaginal rings etc) should be returned to pharmacies for disposal.

5. Empty pharmaceutical packing should be sorted as other household garbage.

6. Become a volunteer and support research and campaigns on assessing the environmental risk of our pharmaceuticals.

How about the manufacturing of medications?

In this blog, I have discussed mainly medications which are prescribed for personal use. The reality of the matter is that a large proportion of the pharmaceuticals found in waters around the world are the result of the manufacturing process.

There is generally a lack of regulation on how much pharmaceutics can be eliminated in the waste waters close to the pharmaceutical factories. For more information on this topic please watch this talk of Professor Joakim Larsson from Gothenburg University, Sweden.

And, while doing research for this blog, I found a wonderful short film which highlights what I want to leave you with as a take home message.

From Charles Darwin’s time and his “On the origin of the species”, we know that the fittest have the highest chances to survive. We are the result of a permanent interaction between the genetic material from our parents and the environment. Given the rapidity with which human activity is impacting our environment including modifying the genetic material of other species, I am wondering where these changes will lead to.

It looks like in the era of Anthropocene (the Human Era ) everything is possible.

But do we really want to transform the useful frog in a handsome prince that we do not need?

Photography courtesy of Kristian H. Reveles Jensen


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