Antipsychotics as environmental pollutants: An underrated threat?

Abstract

The heterogeneous class of what we nowadays call antipsychotics was born almost 70 years ago with the serendipitous discovery of chlorpromazine. Their utilization is constantly growing because they are used to treat a diverse group of diseases and patients across all age groups: schizophrenia, bipolar disease, depression, autism, attention deficit hyperactivity disorder, behavioural and psychological symptoms in dementia, among others. They possess a complex pharmacological profile, acting on multiple receptors: dopaminergic, serotoninergic, histaminergic, adrenergic, and cholinergic, leading scientists to call them “agents with rich pharmacology” or “dirty drugs”. Serotonin, dopamine, acetylcholine, noradrenaline, histamine and their respective receptors are evolutionary ancient compounds, and as such, are found in many different living beings in the environment.

Antipsychotics do not disappear once excreted by patient's urine or faeces and are transported to wastewater treatment plants. But as these plant's technology is not designed to eliminate drugs and their metabolites, a variable proportion of the administered dose ends up in the environment, where they have been found in almost every matrix: municipal wastewater, hospital sewage, rivers, lakes, sea and even drinking water.

We believe that reported concentrations found in the environment might be high enough to exert significant effect to aquatic wildlife. Besides, recent studies suggest antipsychotics, among others, are very likely bioaccumulating through the web food. Crucially, psychotropics may provoke behavioural changes affecting populations' dynamics at lower concentrations.

We believe that so far, antipsychotics have not received the attention they deserve with regards to drug pollution, and that their role as environmental pollutants has been underrated.