Anti-depressants disrupt fish's brains

Jul 04, 2014
Anti-depressants disrupt fish's brains

Drugs designed to ease the symptoms of mental health problems such as depression, obsessive compulsive disorder and post-traumatic stress can have major disruptive effects on aquatic animals' brains, say scientists.

Anti-depressants are some of the most commonly prescribed drugs in the world. In 2012, there were more than 50 million of the drugs in the UK, and in some towns and cities as many as one in six of us are taking them.

In recent years, researchers have found increasing concentrations of the drugs in rivers around the world. Most of them find their way into waterways via sewage and waste water systems, from human waste or from people flushing unwanted prescriptions down the toilet.

A suite of new research, published in a special issue of the journal Aquatic Toxicology, points to mounting evidence that they could be damaging aquatic species.

Researchers have found that fish exposed to tiny concentrations of the drugs in the laboratory can become more aggressive, less cautious, and even lose their ability to camouflage.

In other , their ability to find food and reproduce was affected, their behaviour patterns were altered, and some became more attracted to light. There is also evidence that the drugs may disturb genes controlling the brain function of shrimp.

'In the 90s there was lots of concern about the so-called gender-bending properties of contraceptive drugs that were finding their way into our rivers,' says Dr Alex Ford from Portsmouth University, who edited the special issue.

Anti-depressants disrupt fish's brains
Signal crayfish.

'There is now substantial evidence from laboratory tests that anti-depressnats can affect animals' behaviour and basic functions even at the very low concentrations that they would be likely to encounter in the wild.'

Most anti-depressants work on the part of the brain which controls the amount of mood-influencing hormones released into the blood stream - usually serotonin. Many aquatic creatures also produce serotonin and appear to be sensitive to the effects of the drugs.

In one experiment, a shrimp was placed in a test-tube which was then lowered into a tank with cuttlefish. Whereas fish not exposed to the drugs would soon give up on the unobtainable snack, those exposed to the anti-depressant continued to slam into the tube, wasting vital energy in the process.

In another, a group of male crayfish became more aggressive - fights lasted longer and rates of female mortality rose sharply. There was even evidence that the ability of cuttlefish to camouflage against their backdrop was hampered by the drugs.

If this were repeated in the wild, it could make the creatures more vulnerable to predators. But for now, difficulties in accurately monitoring exposure levels and animal behaviour in the wild are proving a significant barrier to understanding the threat of anti-depressants in the real-world environment.

And some scientists caution that the effects of the drugs need to be tested at a variety of doses before more robust conclusions can be drawn.

'As a proportion of the whole US population, there are probably as many people taking these drugs now as there are on the contraceptive pill,' says Ford.

'At the moment, it's almost impossible for regulators to work out what is a safe level for these drugs in the environment.'

He warns that these problems are not unique to anti-depressants. Humans consume hundreds of different drugs every day, and many are likely to find their way into sewage and, eventually, the environment.

There has been talk of increasing the requirements on to remove the chemicals, but the costs of doing so make it unlikely to happen anytime soon.

Many countries are instead focusing on those drugs which go unused, encouraging people to take unwanted prescriptions back to their pharmacist instead of flushing them away.

'Like many people, my kitchen drawer at home is full of drugs that are long out of date and no good to anybody,' says Ford. 'We don't want to stop people taking drugs, they obviously save countless lives and bring all sorts of benefits to people, but we need to manage the way that we get rid of them.'

Explore further: Fish exposed to antidepressants exhibit altered behavioral changes

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User comments : 5

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rockwolf1000
5 / 5 (2) Jul 04, 2014
"In one experiment, a shrimp was placed in a test-tube which was then lowered into a tank with cuttlefish. Whereas fish not exposed to the drugs would soon give up on the unobtainable snack, those exposed to the anti-depressant continued to slam into the tube, wasting vital energy in the process."

Cuttlefish are invertebrates and are not "fish". They are more closely related to Octopi and Squid.

http://en.wikiped...ttlefish
otero
Jul 04, 2014
This comment has been removed by a moderator.
Woodge
5 / 5 (1) Jul 04, 2014
"Most anti-depressants work on the part of the brain which controls the amount of mood-influencing hormones released into the blood stream - usually serotonin."
Wrong info again - serotonin is a neurotransmitter, not a 'mood-influencing hormone', and it is not 'released into the blood stream' - it travels between the receptors of nerve cells to send messages.
(Could this simply be an attack on successful psychiatry?)
otero
Jul 04, 2014
This comment has been removed by a moderator.
Uncle Ira
2.3 / 5 (3) Jul 04, 2014
Many fishes here are using to downvote the otherwise rightful posts, as it drives them to depressions..


That really bother you that much Cher? Maybe you should take some anti-drepressors for that or maybe quit looking at them so often.
otero
Jul 04, 2014
This comment has been removed by a moderator.
Uncle Ira
1 / 5 (2) Jul 04, 2014
Are you really bothered with what I'm saying here? Antidepressants are good for naive TV-watching housewives separated from actual reality.


Socratic-Skippy you know by now you never bother me no. Cher, you are the reason I got here in the first place.

What you watch on the television? I like the Leverage show, but they ran out of new ones a couple of years ago. Now I watch them all the time on the dvd player because Mrs-Ira bought me the boxed up set of them all. Did you used to get that over there in the place you live? The Leverage? Hooyeei they are the big fun, you should try them on the dvd if you can't get them on your television rerunning.
Lex Talonis
1 / 5 (1) Jul 05, 2014
The most drug fucked nation on earth pisses and shits it's way into fucking up the worlds eco system.... which is good for all the life that is stressed from acid oceans, chemicals, pollution, fertilisers, plastic shit, leaded fuels, blah, blah, blah, blah...

Yay for the Merkin Drug Pushin Business.

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