How Sleep Affects Employee Mental Health and Job Performance in Ireland

High-quality sleep plays a critical role in our overall wellbeing, with well-rested employees reaping the benefits of sharper cognitive function, increased energy and greater physical health.

Unfortunately, some organisations still believe in and promote a workplace culture in which employees dedicate themselves to their work at the expense of sleep and ample rest. Employees experiencing unhealthy workplace pressure may compensate by waking up extra early or working later into the night, which maximises output for their employer in the short term only.

While the rise of hybrid working has enabled many employees to obtain a greater work-life balance, others may find that the lines between their professional and personal lives have become blurred. This can result in a mindset of total professional commitment, both at home and in the office.

On the surface, this may seem beneficial for organisations. In reality, the unrealistic expectations of total commitment and availability can quickly lead to increased stress, feelings of resentment and, ultimately, burnout. During this period of deteriorating mental wellbeing, employees may find that they sacrifice their sleep for work, or that their sleep is negatively impacted by poor mental health. This accelerates the development of burnout.

Over time, an unhealthy workplace culture can lead to a toxic working environment, employee disengagement and eventually staff turnover. Of course, all these issues result in major financial consequences for a business.

This is why ensuring you exercise your duty of care and promote healthy habits, particularly sleeping habits, can help your people work at their best and your organisation flourish.

Why is sleep important for work and job performance?

According to the NHS, a healthy adult typically requires between 7-9 hours of sleep to maintain a healthy lifestyle. It is worth noting that some people naturally need more sleep than others, and factors such as sex, age and health status can alter how much sleep we require.

A good night’s sleep is an essential component of job performance. Studies have consistently shown that sleep is crucial to restore our cognitive function, improve our focus, regulate our mood, and maintain our physical wellbeing.

Despite this, research has found that a significant proportion of UK adults, often between 50% and 70%, do not get enough sleep. In addition, Mental Health UK found that 37% of adults in the UK believe that work reduces the amount of control they feel that they have over their sleep.

Why should sleep matter to employers?

A sleep-deprived employee cannot perform at their best.

It is not possible to achieve the best performance as a business when employees are operating on insufficient sleep, or when your organisation is experiencing increased absence rates due to employees being overworked.

A culture that promotes productivity at the expense of healthy rest can lead to increased absence rates, poor performance and decreased work ethic and morale. If you don’t do your due diligence as an employer to ensure your people are looking after themselves, you could be putting them, as well as your business, at risk.

Whilst the impact of employee absences may be immediately apparent, leading to increased costs for the organisation, the lack of quality output caused by presenteeism can be a subtler financial drain.

Fortunately, many of these risks can be easily mitigated when organisations ensure that employee wellbeing is prioritised as readily as productivity.

What happens if we don’t get enough sleep before work?

Even the odd night of sleep loss can significantly impact our cognitive function the next day. Poor quality sleep is linked to cognitive issues, including reduced focus, memory loss and difficulty regulating emotions. This can result in workplace challenges, such as an employee making mistakes they ordinarily would not make or becoming more irritable than usual with colleagues.

Physically, sleep deprivation can lead to impaired immune function, which increases susceptibility to common illnesses. This means that employees are more likely to require time off to recover which increases sickness absence. If employees attend work when they are unwell with a contagious illness, they may be less productive or spread the illness to colleagues.

Ultimately, when sleep deprivation becomes a consistent pattern, it can greatly affect our mental and physical health. Employees may notice a knock-on effect in which their professional resilience, including their ability to manage stress, is also impacted. This reduced capacity to manage stress can exacerbate mental health conditions, including anxiety and depression.

By recognising the importance of sleep for organisational success, businesses can achieve an upturn in employee productivity and workplace engagement.

How can sleep affect work and mental wellbeing?

In short, healthy sleep and workplace productivity are symbiotic. If employees are deprived of adequate sleep, they may experience:

• Increased fatigue

• Poor focus and output

• Increased risk of cold and flu

• Problems with memory recall

• Headaches or muscle tension

• Irritability or low mood

• Increased symptoms of existing mental health conditions

When an employee experiences some or most of these symptoms, they may be misinterpreted by their employer as unmotivated, irritable and incapable of carrying out their role effectively. This could result in disciplinary measures, formal warnings being issued and, if issues persist for an extended time, dismissal.

In reality, the employee may be struggling to manage an unrealistic workload, trying to impress their employer at the expense of adequate rest or experiencing personal issues outside of work that affect their ability to get a good night’s sleep.

Stress and burnout

When employees experience sleep deprivation, they may be at an elevated risk of experiencing burnout.

The World Health Organization (WHO) defines burnout as ‘a syndrome resulting from chronic workplace stress that has not been successfully managed’. WHO recognises that burnout is an occupational phenomenon, meaning it is something that comes from work-related stress rather than a medical condition.

Sleep deprivation can exacerbate the downward trajectory of an employee who is approaching burnout. Research indicates that sleep deprivation can reduce our ability to regulate emotions, which may make it more difficult for an employee to successfully manage work-related stress.

Physical manifestations

As mentioned, physical health can be greatly impacted by sleep.

Sleep deprivation understandably impacts an employee’s energy levels, which in turn can affect day-to-day functioning and make it difficult to maintain a healthy lifestyle. Reduced energy can impact an employee’s exercise routine or diet, and the employee may be more likely to rely on unhealthy habits such as increased caffeine, nicotine or alcohol consumption to cope.

If an employee leans on unhealthy coping skills for an extended period, they may face an elevated risk of certain medical conditions. Chronic lack of sleep in itself is linked to conditions such as obesity, diabetes and heart disease. Sleep is not just essential for professional performance, but also to remain healthy for years to come.

The economic impact of sleep deprivation

Sleep deprivation and failure to effectively manage it can cost organisations significant amounts.

Studies by RAND Europe have found that in the UK, sleep deprivation results in the loss of over 200,000 working days each year. This is due to a combination of absenteeism and presenteeism. The study also estimated that insufficient sleep costs the UK economy up to £40 billion annually through reduced productivity and increased health risks.

The impact of sleep deprivation might go unnoticed in the moment, but the costs add up over time.

Improving job performance with sleep

Sleep impacts every area of an employee’s life. With approximately 20% of a person’s week spent working, the effect of sleep loss on workplace performance can become rapidly evident.

Fortunately, some simple adjustments can be made by an employee and an organisation to help improve the sleep quality of employees. This can have a domino effect whereby the quality of an employee’s professional performance and output improves.

1) Develop and stick to a sleep schedule

Maintaining a regular sleep schedule allows us to get sufficient high-quality sleep.

The first step in achieving this is by waking up and falling asleep at the same time every day. When we regulate our sleep-wake times, we stabilise our circadian rhythm. The circadian rhythm, the body’s 24-hour internal clock, coordinates sleep-wake cycles, hormone release, body temperature, and other responses.

When building a healthy sleep schedule, it is important to consider overall sleep hygiene as well as sleep-wake times. Sleep hygiene refers to healthy habits and environmental conditions that support good‑quality sleep, and it begins as soon as we wake up in the morning.

In short, good sleep hygiene puts us in the best possible position for sleep each night:

• Get 30 minutes of sunlight first thing in the morning.

• Nap for no more than 20 minutes, ideally in the early afternoon.

• Avoid caffeine, alcohol and nicotine in the hours before sleeping.

• Avoid using screens an hour before going to sleep.

• Make sure that the bedroom is dark, cool and quiet.

Some employees may not be aware of the steps they can personally take to improve their sleep hygiene and elevate their bedtime routine. Organisations can boost employee awareness by offering wellbeing workshops or webinars that provide their people with clinically informed education and practical steps to obtain the best quality sleep.

Centring sleep as a crucial aspect of employee wellbeing can also be hugely impactful for organisations. By regularly checking in with employees about their wellbeing and keeping an eye out for warning signs that an employee may be struggling with their sleep, employers can proactively support their people. If an employee is regularly expressing tiredness, fatigue or difficulty concentrating, they may not be getting adequate sleep.

2) Incorporate physical activity into your daily routine

Employees often express that feeling too energised at the end of the day leads to difficulty sleeping. This can be caused by various factors, including poor sleep hygiene, eating too late in the day and working in a role that requires minimal activity (i.e. in an office).

Energy from food is continually used by the body throughout the day for essential processes such as breathing, circulation and brain function, as well as physical activity. However, when a person has a sedentary lifestyle, less energy is expended and any excess may be stored for later use.

Sedentary behaviour refers to long periods of sitting or lying down while awake, with very low energy use. The NHS notes that many adults spend over 7 hours a day sedentary, often without realising it. Common examples include desk work, long commutes, screen time, or sitting for leisure.

Incorporating even light movement, such as a short walk at lunchtime, into the workday has been shown to improve sleep quality. Expressing the importance of this movement to employees can raise awareness of the benefits for their sleep hygiene.
Increased movement improves sleep, which enhances workplace performance and physical health. This leads to a positive domino effect on overall wellbeing.

3) Managing stress for better sleep

Personal circumstances or workplace difficulties can cause employees to experience stress, anxiety and rumination, all of which can impact their ability to fall and stay asleep.

Workplace support for employees experiencing high levels of stress is crucial. When an organisation has a culture that prioritises mental health awareness and encourages open conversations about wellbeing, employees feel safe enough to share any difficulties they are facing with their managers. This allows leaders to take appropriate action to support their employees, whether their stress relates to the workplace or their personal lives. Managers that feel comfortable having supportive conversations with their people can be an invaluable and empowering presence at a challenging time in an employee’s life.

If an employee cites workplace stress as a significant contributing factor to sleep loss, organisations should take swift, appropriate action to support the employee. If suitable, considering the employee’s workload or offering additional training can help them feel competent and confident.

If an employee is experiencing personal problems or poor mental health unrelated to the workplace, it can feel daunting for a manager to navigate, especially if they place overly high expectations on the support they are offering. Whilst leaders should not be expected to offer counselling or ‘fix’ the employee’s problems, there are helpful ways they can offer support.

With a solid foundation of mental health awareness, leaders can employ active listening skills to facilitate empathetic conversations with employees. If the employee is dealing with health conditions or distressing personal circumstances, confident signposting to appropriate professional support can make a huge difference.

How an Employee Assistance Programme help build better sleep habits for workplace performance?

Effective signposting can involve directing employees to their Employee Assistance Programme to access mental health support.

With HA | Wisdom Wellbeing’s Employee Assistance Programme, expert support is readily available from legal advisors and registered, qualified counsellors, 24/7, 365 days a year. HA | Wisdom Wellbeing’s EAP counselling service provides employees with the necessary therapeutic support and coping strategies to build their resilience and improve their mental wellbeing.

Our counsellors are trained in Solution-Focused Brief Therapy (SFBT), which is a model that provides short-term goal-oriented counselling to ensure people can better understand and overcome the problems they are facing. This includes dealing with stress, burnout and anxiety, all of which can impact sleep.

Conclusion

Sleep is a key component of our overall wellbeing and relates to almost every aspect of everyday life. This is especially true regarding workplace performance. Professional environments require high levels of focus and motivation, and a lack of sleep can impact an employee’s ability to perform to a high standard.

If workplace expectations are not met, an employee may experience increased levels of stress which can further negatively impact sleep. This can be a difficult cycle to escape from and can result in more worrying physical and mental health concerns. Ensuring that your employees have good sleep hygiene is not only essential for individual workplace performance, but also for a positive organisational culture.

Frequently asked questions about sleep and workplace performance

Can you feel ill from lack of sleep?

Yes. A lack of sleep has been proven to weaken the immune system, which increases susceptibility to illnesses such as the common cold. Additionally, the symptoms of sleep deprivation (fatigue, body aches, impaired concentration, reduced alertness) can resemble those of physical illness, making it difficult to distinguish between the two.

What are the effects of not getting enough sleep?

Mentally, sleep deprivation can worsen our cognitive function and cause us to feel sluggish throughout the day. It can also worsen the symptoms of existing mental health conditions such as anxiety and depression.

How can HR spot sleep deprivation in employees?

HR can spot sleep deprivation by noticing consistent patterns in behaviour and performance. A sleep-deprived employee may be yawning, drowsy, irritable, or complain of headaches/dizziness more frequently. Their workplace performance may also drop significantly, leading to increased errors and reduced productivity. HR should look for a pattern of these signs over time rather than focusing on the odd day of lower output or fatigue.

What workplace policies improve employee sleep?

Strong workplace policies show a visible commitment to supporting employee wellbeing. Policies that improve employee sleep include:

• Predictable scheduling: where possible, provide employees stable hours and advance notice, avoiding short gaps between shifts.

• Regular rest breaks: ensure that employees take sufficient breaks to boost alertness and reduce errors.

• Adequate sleep education: provide training for employees to enhance their sleep hygiene.

• Employee wellbeing check-ins: schedule regular 1:1s so managers can identify early warning signs and provide support.

Related entities

Sleep deprivation A prolonged lack of restorative sleep that impairs cognitive function, mood regulation and physical health. The document notes that even “the odd night of sleep loss can significantly impact our cognitive function the next day”, leading to reduced focus, irritability and increased illness risk.

Burnout A work‑related syndrome caused by chronic, unmanaged stress. The WHO definition is cited in the document, describing burnout as resulting from “chronic workplace stress that has not been successfully managed”. Sleep deprivation accelerates this trajectory.

Presenteeism When employees attend work despite poor health or exhaustion, resulting in reduced productivity. The article highlights presenteeism as a “subtler financial drain” compared to absence.

Absenteeism Time away from work due to illness or poor wellbeing. Sleep deprivation increases susceptibility to illness, raising sickness absence and organisational costs.

Circadian rhythm The body’s 24‑hour internal clock regulating sleep‑wake cycles, hormones and temperature. The document explains that stabilising sleep and wake times helps regulate this rhythm.

Sleep hygiene Daily habits and environmental conditions that support high‑quality sleep. The article outlines practical steps such as morning sunlight, limiting caffeine, reducing screen time and maintaining a dark, cool bedroom.

Sedentary behaviour Long periods of sitting or inactivity that reduce energy expenditure. The document notes that many adults spend over seven hours sedentary, which can negatively affect sleep quality.

Employee wellbeing A holistic approach to supporting mental, physical and emotional health at work. The article emphasises that prioritising wellbeing is as important as productivity for organisational success.

Employee Assistance Programme (EAP) A confidential support service offering counselling, legal advice and wellbeing guidance. The document highlights HA | Wisdom Wellbeing’s EAP as a key resource for employees experiencing stress, burnout or sleep difficulties.

Solution‑Focused Brief Therapy (SFBT) A short‑term, goal‑oriented counselling model used within HA | Wisdom Wellbeing’s EAP to help employees build coping strategies for stress, anxiety and sleep‑related issues.