Your team is exhausted. Insomnia is likely part of the picture.

"On average, 1 in 5 of your employees didn’t sleep properly last night. Most won’t tell you. And it's costing you more than you think."

You've invested in mental health days. You've rolled out the EAP. You've trained managers to spot the signs of burnout. And yet something still feels off - a low-level fog across the organisation. Meetings that drag. Decisions that take longer than they should. Good people running on empty.

There's a good chance you’re looking at the wrong problem.

Burnout gets the headlines. But underneath it, often preceding it, and frequently mistaken for it, is something far more common and far less discussed in HR circles: insomnia.

What insomnia actually is (and what it isn’t)

Most people think of insomnia as the occasional bad night, but that’s just being human. Insomnia is something different and it doesn’t follow a single rule; according to the ICSD-3 (the international clinical standard), it primarily manifests in two ways: short-term insomnia, which typically triggers during spikes of stress or sudden life changes, and chronic insomnia disorder.

The latter, chronic insomnia disorder, is a persistent pattern (difficulty falling asleep, staying asleep, or waking too early), occurring at least three nights per week, for at least three months, causing real functional impairment during the day. It is not just tiredness and leads to cognitive slowing, emotional dysregulation, and a reduced capacity to concentrate, decide, and communicate.

Furthermore, insomnia rarely travels alone. There is a strong, often bidirectional relationship between sleep deprivation and other health conditions. It frequently co-occurs with mental health disorders like anxiety and depression, acts as a red flag for other sleep disorders such as Obstructive Sleep Apnea (OSA) or is severely aggravated by medical conditions like chronic pain and mobility issues.

In Portugal, where modern work culture increasingly blurs the boundary between "on" and "off," a representative study revealed that nearly 43% of adults report sleep disturbances, with nearly 20% suffering from chronic insomnia. Across Belgium, while the strict clinical rate is lower at 11%, the underlying drivers remain identical: screens in bed, job precarity, and the structural pressure of an "always-on" professional life. Alarmingly, local data shows that while roughly a quarter of the population meets the clinical criteria for insomnia, only about 10% have ever received a formal diagnosis.

The cost you’re not measuring

Here's where the numbers become hard to ignore.

Research on the organisational impact of insomnia is consistent and damning. Employees with clinical insomnia take, on average, 5 to 9 extra sick days per year and experience up to 58% greater productivity loss compared to healthy sleepers. In roles that require precision, judgement, or client-facing communication, the performance gap is even wider.

When you aggregate that across your workforce, the picture shifts from a personal health issue to a balance sheet problem. It is estimated the total employer cost of untreated insomnia (accounting for absenteeism, presenteeism, errors, and turnover) at between €2,500 and €4,000 per affected employee, per year.

For a company of 100 people, where statistically 20 are dealing with clinical insomnia right now, that's a potential drag of €50,000 to €80,000 annually. Not from a crisis. Not from a scandal. From a condition that most organisations have never once addressed directly.

The burnout connection

There's another reason HR leaders should care about this specifically: when high-performing talent is chronically sleep-deprived, executive function, critical thinking, and emotional resilience are the very first things to drop. Recognizing these early warning signs is especially critical for those in high-stakes roles, key decision-makers, and employees facing prolonged pressure or irregular demands.

The relationship between sleep deprivation and stress is bidirectional: poor sleep raises cortisol levels and reduces the brain's capacity for emotional regulation, which makes work stressors harder to absorb, which disrupts sleep further. It's a cycle, and it accelerates. What begins as difficulty sleeping after a difficult project can, within months, become the chronic dysregulation we label burnout.

By the time someone lands in your EAP for burnout support, they've often been sleeping badly for a year. Treating the burnout without addressing the sleep is, in many cases, treating the symptom.

Why most interventions don’t work

When employees do seek help, or when organisations try to provide it, the usual tools fall short.

• Sleep hygiene advice (no screens before bed, cooler rooms, consistent wake times) is not wrong, but it addresses the conditions around sleep, not the mechanisms of insomnia itself. For someone with clinical insomnia, being told to "wind down earlier" is the equivalent of telling someone with a broken leg to "try walking more carefully."

  
  

• Meditation and relaxation apps have genuine value for stress management. They are not a treatment for insomnia. The evidence base simply doesn’t support them as a cure for a clinical sleep disorder.

  
  

• Sleeping pills (still the most common response from GPs) treat the symptom acutely while often making the underlying problem worse over time. They suppress the sleep architecture that needs to be retrained, and they create dependency patterns that complicate recovery.

  
  

The only intervention with a strong, consistent evidence base for treating insomnia at the root is Cognitive Behavioural Therapy for Insomnia, CBT-I for short. For now, the more immediate question is: do you know how many of your employees are affected?

Find out, for free. Mirror SleepWise offers a scientifically-validated insomnia assessment: anonymous, three minutes, no strings attached. Take the Free Insomnia Test at mirrorsleepwise.com

Mirror SleepWise is a science-based digital therapy for insomnia, grounded in CBT-I principles, trusted by partners including Helan Insurance and Hospital da Luz.

Martin Popevic’s (Clinical Sleep Medicine, Certified Somnologist) comment

Chronic insomnia is more than a bad night; it worsens physical and mental health while severely draining workplace productivity and focus. Fortunately, we can treat it early simply through open communication by identifying daily stressors and correcting behaviors before it escalates.

This article was written by the Mirror SleepWise team as a guest post for the BoundmakersBlog.