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The Evening Standard
Millions of men who take antidepressants could be damaging their sperm and risking infertility, according to new research.
The findings, described as “alarming” by one leading expert, suggest that commonly described drugs for depression can break up DNA in sperm.
Outwardly the sperm may appear normal in terms of their numbers, shape and swimming ability. But similar levels of DNA fragmentation in sperm are said to have led to fertility and pregnancy problems in the past.
For couples undergoing In-Vitro Fertilisation (IVF) treatment, fewer embryos form when the man’s sperm has damaged DNA. When embryos do form, they are less likely to implant in the womb – which is essential for a successful pregnancy.
The link with antidepressants was discovered by Professor Peter Schlegel and Dr Cigdem “Cori” Tanrikut at the Cornell Medical Center in New York City.
In 2006, the two fertility scientists reported that two men had developed low counts of healthy sperm after taking two different antidepressants. Both were selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed class of antidepressant which work by altering levels of a brain chemical that influences mood.
Now the team has followed up the research by studying 35 healthy men given one of the most popular SSRIs, paroxetine. The drug, made by pharmaceutical giants GlaxoSmithKline, is sold as Seroxat in the UK and Paxil in the US.
The scientists examined the men’s sperm before treatment and after they had been taking the antidepressant for a month. Superficially, the sperm appeared healthy, New Scientist magazine reported. But closer examination using a sophisticated detection method called Tunel (Terminal deoxynucleotidyl transferase biotin-dUTP Nick End Labeling) which flags up broken strands of DNA, revealed a worrying picture.
On average, the proportion of sperm cells containing fragmented DNA rose from 13.8% before taking paroxetine to 30.3%. Many experts regard a sperm DNA fragmentation level of 30% as “clinically significant”. In the space of just four weeks, therefore, the men’s sperm had suffered a degree of damage that potentially could impair fertility.
The new findings will be presented in November at a meeting of the American Society for Reproductive Medicine in San Francisco.