Here I offer nuggets from the latest research on HSPs and sleep—a highly pertinent topic for sensitive people.
Who could possibly resist this face? My son couldn’t… he found this kitten under the dumpster after work the other night. You can guess what happened next.
We went over immediately to meet the new arrival. He’s even more irresistible in person. His status in his new household is uncertain, however (it all depends on how well he gets along with the rabbit.)
That night before bed, my partner muttered something “maybe having a cat.” I could hardly believe it. He’s a bit allergic, and we had nixed the idea in the past for various reasons.
That night I woke up with a start at 3 AM thinking, “Where will we put the litter box?!” Then I started laughing. I’d been working on this article about highly sensitive people (HSPs) and sleep, and now here I was, wide awake in the night. Clearly my excited brain had grabbed the kitten idea and scampered away with it.
Fortunately, my sleep disruption was, as sleep researchers call it, situational. I slept fine the next night. But like many HSPs (and many people generally, around the world), I do sometimes have trouble falling asleep, staying asleep, or sleeping deeply, and I feel awful when I don’t get enough sleep. I’m keenly interested in any information that might help me sleep better.
No wonder I got so excited when I came upon an HSP-and-sleep-related research study published in 2024 by Dr Luca Simione and Ilde Pieroni on the Sensitivity Research blog. (Note: I highly recommend this website and blog. They send out ten or so emails a year, providing clear, easily-to- understand summaries of the latest research on the HSP trait.)
What is sleep reactivity?
Simione and Pieroni concluded that “heightened sleep reactivity explains the relationship between sensitivity and sleep disruption,” adding that their study “holds potential for helping sensitive people overcome their sleep problems.” I was intrigued. But what on earth was sleep reactivity?
Searching for an answer to that question, I found an impressively comprehensive research-summary article on the National Center for Biotechnology Information website of the National Institute of Health. It references no fewer than 170 studies related to sleep, stress regulation, and insomnia.
The research studies quoted in this article did not explicitly focus on HSPs. However, they did focus on sleep reactivity. Now that Simione and Pierone have proved that sleep reactivity particularly affects highly sensitive people, we know that all the existing research about sleep reactivity is highly relevant for us.
With HSP relevancy in mind, I waded through the NCBI article. The original language is dense and technical. Any mistakes of translation are entirely mine. All this information comes from the NCBI article, unless otherwise noted; specific quotations from that article are marked with an asterisk. Let’s start with sleep reactivity.
Sleep reactivity is the trait-like degree to which stress exposure disrupts sleep, resulting in difficulty falling and staying asleep. Individuals with highly reactive sleep systems experience drastic deterioration of sleep when stressed, whereas those with low sleep reactivity proceed largely unperturbed during stress.*
In other words, different people react very differently to stress. A given stressor may cause you a sleepless night, while your neighbor might experience the same stressor then be able to lie down and fall asleep without any problem. The upshot? HSPs are vulnerable to sleep disruption when stressed.
In fact, Simione and Pierone’s detailed analysis found that “the effect [of sleep reactivity on HSPs] remained significant even after accounting for factors like age, gender, and personality traits.” Let’s unpack this more.
Understanding HSP sleep reactivity
We know there are many factors that affect humans who are trying to sleep. For example, most people have more trouble sleeping as they age. Also, people who are temperamentally anxious suffer more from sleep challenges.
However, Simione and Perione found that the tendency for HSPs to have higher sleep reactivity exists independently of all these other factors. Their findings were clear, showing “a positive correlation between sensory-processing sensitivity, sleep reactivity, and insomnia symptoms.”
Why is this a big deal? I learned that only relatively recently did researchers establish “whether people are stressed out because they aren’t sleeping, or whether the fact they already tended to get stressed out caused them to have trouble sleeping.”* This struck me as an important question—one with big implications for treatment and prevention of sleep problems.
Now we know that for HSPs, the answer is “both.” That is, getting stressed out during the day makes it harder for us to get to sleep and stay asleep, because of our relatively high sleep reactivity. Simultaneously, our deep-processing minds can get us into even deeper trouble if we lie awake and ruminate, whether the rumination is about not sleeping or about where to put the litter box.
The bad news: HSP environmental susceptibility affects our sleep
Everybody has some degree of sleep reactivity. As Simione and Pierone showed, though, HSPs as a group experience high sleep reactivity. This is not surprising, considering that variable susceptibility, also called environmental susceptibility, is a key aspect of being highly sensitive. We are more positively affected by positive stimuli and situations, and more negatively affected by negative stimuli and situations.
Simione and Pierone explain that for HSPs,
…sleep problems are more related to carrying daily stress into sleep (sleep reactivity) than general stress levels….this pattern aligns with the characteristics of highly sensitive persons (HSPs), who react more strongly to environmental stimuli and are more likely to experience high stress levels (4). As a result, they may be at a higher risk for the development of sleep problems.”
The good news is, the fact that we have high sleep reactivity generally doesn’t mean HSPs will always sleep poorly. However, if we are exposed to dysregulating environmental stimuli during a given day, we are more likely to retain that stress and to be unable to fall asleep or stay asleep that night.
My nocturnal kitten ruminations were a perfect example. Adopting a cat would have many implications for my partner and me. It could be amazing. At the same time, we’d have to make some significant changes around the house. The very possibility stimulated my HSP brain into overdrive.
The good news: environmental susceptibility can also help us sleep
We know HSPs are sleep reactive because we are environmentally susceptible. This comes with a bright side, though: environmental susceptibility cuts both ways. We do get overstimulated more easily. However, we are also highly susceptible to the potent calming effects of meditation, breath practices like coherent breathing, and physical interventions like restorative yoga or a hot bath.
I’ve written often about the importance of self-regulating practices for HSPs. Sleep is another area in which our state of regulation has a huge effect on our well-being and ability to function. The NCBI article mentions a study in which “the authors pointed to reduced parasympathetic activity as a potential autonomic marker of situational insomnia.”
These findings suggest that stress reactivity within the sleep system is consistent across various situational stressors for a segment of historically good sleepers, and that stress-related sleep disturbances may have neurobiological underpinnings in autonomic dysregulation.*
In other words, the research suggests that even if you are generally a good sleeper, you will likely experience stress-related sleep disturbance if you get dysregulated (“dysregulation” is another word for “reduced parasympathetic nervous system activity.”) Conversely, if you can do something before bed to let go of any stress and dysregulation you’ve accumulated during the day, you can counteract your sleep reactivity and improve your sleep.
Simione and Perione confirm all this, and they offer additional suggestions:
Pre-bedtime meditation or relaxation techniques can be very effective for HSPs. These practices help release daily stress and reduce nighttime mental activity, improving daytime functioning and emotional well-being….Knowing that highly sensitive individuals are more prone to sleep issues during stressful times can help therapists provide tailored sleep advice and assess sleep reactivity in HSP clients. Mindfulness-based interventions (8) and cognitive-behavioural therapy for insomnia (CBT-I) can also be effective.
My conclusion: prevention is our most powerful tool
Everyone needs sleep, but HSPs suffer particularly badly if we don’t sleep well. Taking in all this fascinating and pertinent research reinforces my conviction that where sleep is concerned, HSPs need to be devotedly proactive. This is truly a case of the old saying, “an ounce of prevention is worth a pound of cure.” Insomnia, once it develops, can become a debilitating and self-perpetuating condition, so we need to address sleep challenges early and effectively.
How do you do this? To review: experiment with calming pre-bedtime routines. Cultivate your ability to self-regulate by practicing coherent breathing to permanently lower your standing level of nervous system arousal. Learn breath practices to calm you in the moment. Discipline your mind with meditation. Get sleep-oriented therapeutic support as well, if you need it.
Even if you do already have insomnia, Simione and Pierone have noted that “addressing sleep-related difficulties specifically can help HSPs with insomnia.” In short, we have great tools. And here’s even better news: these are all the practices I recommend to all HSPs. Many of them cost nothing, feel great, and have long-term positive benefits…so improving your sleep is just one more reason to do them.
Thanks to Simione, Pierone and all the other researchers whose painstaking work is bringing us this invaluable, empowering information.
Image: 2024 Cal Brickman. Thank you Cal!
