Owning cat while pregnant linked to increased risk of postpartum depression, study finds

Owning a cat while pregnant has been linked to an increased risk of postpartum depression in a new study – which also found the reverse to be true for dog ownership.

The researchers at Japan’s University of Toyama were unable to explain the association they discovered between cat ownership and a heightened risk of mental health issues in new mothers.

But the paper’s lead author Kenta Matsumura said the findings suggested that special attention must be paid to cat owners, who are also at a higher risk of toxoplasmosis – an infection which can cause miscarriage or stillbirth in some cases.

In their search to understand the relationship between pet ownership and a mental health among pregnant women and new mothers, Dr Matsumura’s team created a questionnaire to collect information on demographic and socioeconomic status, medical and obstetric history, physical and mental health, lifestyle, and other topics.

This was then sent to more than 80,000 mothers from across 15 regions of Japan, who lived in both rural and urban areas.

These women were asked to complete these surveys five times between early stages of their pregnancy and a year after the birth of their child – and more than 90 per cent of those involved continued to respond until the final questionnaire.

In the second survey, respondents were asked to tick a box denoting whether or not they owned a cat, a dog, or both animals. Just shy of 9,000 participants reported being a dog owner, while there were a little over 4,000 cat owners, and nearly 1,300 who owned both.

In findings published this month in the Social Science & Medicine journal, the researchers discovered that owning a dog was associated with reduced symptoms of depression and anxiety at one month and six months after giving birth – and of reduced psychological distress 12 months postpartum.

Conversely, their model found that cat ownership was associated with increased risk of depressive symptoms at six months postpartum.

“These findings suggest that the type of pet owned plays a differential role in maintaining sound mental health in mothers around the birth of their children,” they wrote.

The authors noted that their findings on dog ownership are in keeping with other previously proven benefits of keeping dogs as pets, such as decreased loneliness and increased self-esteem – which could be related to dogs’ ability to use humans’ social cues.

“The convergence of these benefits might be responsible for the reduced all-cause mortality in dog owners,” they wrote, adding: “Against the background of dog domestication in Siberia during the last glacial period about 23,000 years ago, dogs and humans might have coevolved to yield benefits in both species, including human mental health.”

While noting that “the exact mechanism underlying” their findings about cat ownership remained a mystery, the pointed to studies suggesting that cat owners’ self-esteem is lower than that of dog owners – and to the relatively short length of time in which they have lived alongside our ancestors.

They wrote: “In contrast to dogs, cats have a shorter history of living with humans: they began to live with humans in two ways, one traced to about 4400 BC and the other to about 1500 BC, and have undergone minimal genetic change.

“Thus, the coevolution degree is not yet mature enough to produce wide-ranging benefits in humans.”

Dr Matsumura told the Daily Mail: “Our findings suggest special attention must be paid to cat owners, who have a higher risk of developing mental health complications as well as toxoplasmosis.”