A Surprising Twist to My Assumption on Women and Insomnia

Guess who has more insomnia?

Men or women?

You may be in for a surprise...if you had the same thought I did, that is.

Selection bias can lead sleep therapists to assume that more women suffer from insomnia simply because more women ask for help. Even occasionally, I'll have a gent show up and say, "I didn't want to come in, but my wife made me..."

Insomnia around the world

It's essential to question any assumption or bias, of course. In this case, though, even some large and well-organized research studies in Western populations show that women are more frequently affected by insomnia than men.¹

Interestingly, though, this is NOT the case in China or other Asian countries, where men and women have insomnia at similar rates. In these countries, a person's age was the predominant differentiating factor between those with and without insomnia.²

Challenging assumptions about age and gender

We commonly think older people suffer more from insomnia because they sleep less. But these studies showed that those under 43 suffered from more insomnia than those who were older, regardless of gender.²

It could be that women in western cultures are more likely to ask for help, and men are less likely. And it may be that men and women both ask for help equally in Asian countries. However, the physiological data may not support a gender difference either.

Insomnia is a sleep disorder typically characterized by hyperarousal. We've already found out that gender isn't automatically associated with insomnia across all cultures, but could gender be associated with hyperarousal and the development of insomnia be affected by something else entirely?

Gender and hyperarousal

A gender-based association is not supported by the physiological research on hyperarousal either. One study looked at age and gender and the resting "arousal" state of the brain in people with and without insomnia. Gender affected hyperarousal in certain brain regions more than age differences, and age differences affected hyperarousal in the brain more consistently in other regions. But when looking at those with and without insomnia, it was the regions associated with age that was more prone to hyperarousal in those with insomnia. Not gender.³

What is the link between age and insomnia?

I found this quite surprising. Even if there is literature that points in the opposite direction (and doubtless there is) – on this basis alone, what could it be about age that makes a person more prone to developing insomnia?

Indeed, many age-related changes happen in the brain from birth through young adulthood in particular. Could it be that younger people's brains are simply more wired for insomnia?

These are complicated questions that research is still trying to answer; however, it might be interesting to look into the effectiveness of >stress management in younger people and older people.

Stress response

Some people respond to stressful life events in a way that more dramatically than others. This "sleep reactivity" can make a person more prone to not sleeping well and is a trait that is associated with the development of insomnia.³

It may be another bias to challenge, but perhaps younger people of all ages are more prone to sleep reactivity. This could be a result of less life experience in managing stressors, which may be related to the age association with hyperarousal and insomnia.

Avoiding oversimplification

It's tricky to speculate on the wildly diverse impacts upon people's sleep, insomnia, and arousal states. Even the researchers don't fully understand it all. And despite many studies no doubt showing that women may experience more insomnia, I did think it was fascinating to come across some literature that suggested otherwise. It reminded me of the importance of always questioning my assumptions and to look for issues that can create an illusion of a connection, when in fact, it may be a lot more complicated. 

Gender and culture are deeply complex concepts, and insomnia is a complex disorder. Sweeping statements like "women are more prone to insomnia" need to be considered carefully rather than accepted as a simple truth.

Did you also make the assumption that women were more prone to insomnia across the board? Did this surprise you?