Antidepressants in Water Linked to Increased Expression of Autism Genes in Fish

Ingestion of antidepressants during pregnancy has long been associated with an increased risk of autism in the child, however recent work by Thomas et al has opened up another more concerning source of this potential interaction; antidepressants within drinking water.

Antidepressants, along with many other pharmaceuticals and illicit drugs, are present in waste-water, from human ingestion and excretion, and therefore are often also found in drinking water.  The concentrations of even the most highly prescribed drugs are often 1000’s of times lower than a prescribed dose in every litre of water, however the synergistic interactions which can arise from being exposed to a ‘cocktail’ of drugs at low levels is poorly understood.

Thomas’s work exposed Fathead Minnows to such a cocktail of specifically antidepressant drugs whilst they were carrying young.  The genes of the next generation were then tested to see if any were significantly enriched.  Many of the genes associated with idiopathic Autism were.  Genes associated with predisposition to autism, such as Rett, as well as disorders such as Parkinson, MS and Major Depression were also not consistently significantly enriched suggesting that the processes is not a general neuropathy affect but specific to autism.  In addition to increased gene expression the fish also demonstrated abnormal behaviour pattens and tended to panic more easily when startled.

It should be said, that although the article is interesting and definitely indicates more work in the are should be carried out, it should not have you running for the Evian.  There is after all a significant body of work to be carried out before you can leap from behavioural and gene expression changes in fish to a significant increased chance of autism in children from drinking contaminated water during pregnancy.  However I can only hope that this will lead to more research in water treatment and the affects which drugs can have within water, both for future human use as well as for sensitive species within the environment.  The group are now carrying out studies into mammalian responses to these drugs.

Article reference: Thomas MA, Klaper RD (2012) Psychoactive Pharmaceuticals Induce Fish Gene Expression Profiles Associated with Human Idiopathic Autism. PLoS ONE 7(6): e32917. doi:10.1371/journal.pone.0032917


RSC article on Pharmaceuticals in Waste Water and the Withdrawal of ‘Return Unused Drugs’ Policy in US

This article make disturbing reading for me in my field – yes, transporting drugs back to origin will release more CO2 but not disposing of pharmaceuticals responsibly can have huge impacts for the environment.  Surely more appropriate prescriptions and low carbon transport are better paths to follow rather than advising large quantities of drugs to be just chucked away?