Becoming a parent at a very young or very old age may increase the risk of children developing bipolar disorder, a new study suggests - it's thought to be highly heritable, and this latest data, published in the journal European Neuropsychopharmacology, pave the way for future research into factors associated with the development of bipolar disorder.
A team of researchers from Spain, Italy, Australia and the Netherlands reviewed studies that included a total of more than 13 million participants, of whom over 217,000 had bipolar disorder, to see if there was a link between parental age and the risk of bipolar disorder in children.
What they found was a "U-shaped" curve, showing increased risks for both young and older parents compared to parents aged 25-29.
"We can say that earlier and older parental age is associated with an increased risk of bipolar disorder," study leader Giovanna Fico told Euronews Next.
But while there is an increased risk, potential parents in these age groups should not be alarmed, she added. "I don't think they should be too worried. The effect is moderate. But it has an effect."
Men were more likely than other groups to have a child with bipolar disorder: men aged 45 and over were 29% more likely to have a child with bipolar disorder, compared to men aged 25-29 .
This increased risk was also seen in older women, with women aged 35 and over having a 20% higher chance of having a child with bipolar disorder compared to women aged 25 to 29.
At the other end of the spectrum, the researchers also found that children born to young parents (20 and younger) also had an increased risk of bipolar disorder – 23% higher odds for women and 29% for men.
The reasons for this increased risk are still largely unknown, the research team says, but researchers think genetic factors, environmental factors such as socioeconomic problems, lack of support, stress or immunological factors may be involved.
