By Nick Grimm
Stressed-out men can pass on anxiety and depression to their children and grandchildren via their sperm, Australian researchers say.
Studies on mice have revealed that the presence of excessive stress hormones in a male parent prior to conception can cause the following two generations to be moody and depressed.
According to the team from the Florey Institute of Neuroscience and Mental Health, men hoping to father happy and well-adjusted offspring are advised to keep calm and carry on.
Professor Anthony Hannan, who led the research team, said they gave male mice increased stress hormones in their drinking water and then compared them with control male mice who had not received the stress hormones.
“And then we mated those mice with female mice and then we studied the offspring of those mice and what we found were behavioural changes relevant to depression anxiety disorders in the offspring of the male mice with increased stress hormone,” he said.
Professor Hannan said by feeding the mice the stressed hormones, the mice have a single stress hormone molecule circulating in their blood system, giving the researchers a specific way of understanding the mechanism.
“That increased stress hormone changed the contents of the sperm,” he said.
“So it changed what we call epigenetics, so epigenetics means above the genome.
“So if you imagine the genome being an orchestra and the instruments are the genes, and the musicians is the epigenetics and together they create a symphony.
“So the epigenetics dictates where the genes are turned on and off, that’s what it is.
“And so we found changes within the sperm that changes behaviour in the offspring in ways that are relevant to depression and anxiety disorders and this has major public health implications.”
Second generation also feel the effects
Professor Hannan said measuring anxiety levels in mice was carried out by putting them into a maze where the mice have to choose between being in the dark side or the light side.