Mental Health in the Workplace: 6 Red Flags to Watch for in Employees

The 2025 Workforce State of Mind Report by Headspace highlights the growing impact of mental health in the workplace. Based on insights from over 2,000 employees and HR leaders, 92% of workers say their sleep is negatively affected by work, while 58% have considered leaving their job due to poor mental health.

These findings reinforce just how closely workplace stress and employee wellbeing are linked. Employees are increasingly looking to employers for meaningful mental health support, yet many still feel unsupported particularly during key moments such as taking or returning from mental health leave.

While progress has been made in reducing stigma around mental health at work, organisations are now under greater pressure to take action. Supporting employee wellbeing is no longer optional – it’s a business-critical priority that directly impacts retention, productivity, and engagement.

In this blog, we explore how mental health issues can present in the workplace, helping employers recognise early warning signs and identify potential red flags among employees before they escalate.

1) Uncharacteristic Behaviour

What seems like the most obvious can be challenging to identify – uncharacteristic behaviour. We say uncharacteristic, as it is important to remember that no two people have the same personality, and importantly, no one will feel the same way, day in and day out.

For example, some may say that being generally quiet or introverted is a red flag to be mindful of; however, some individuals are naturally a lot quieter or calmer than others, as we all have different personalities.

So, what’s important is to get to know your employees on an individual level, looking out for behaviours and characteristics that are specific to them. This means when it comes to spotting uncharacteristic behaviours like someone who is usually quite outgoing, loud or bubbly acting distant, quiet or generally down, it becomes a lot easier.

Uncharacteristic behaviour can be both sudden and happen slowly over time. It’s important to look for uncharacteristic behaviours often to avoid missing the little signs that have been forming over previous weeks or months.

2) Decrease in Productivity or Quality of Work

Studies have shown over the years that there is a strong correlation between mental health and productivity. Most commonly mental health illnesses such as anxiety and depression have been linked to feelings of disengagement, disinterest, an inability to concentrate or focus and poor levels of productivity.

These behaviours can occur from feeling extremely lethargic or fatigued and are not to be mistaken for laziness or a negative attitude.

An example of this could include an individual repeatedly struggling to meet their deadlines, even though resources have been made available and an appropriate amount of time has been issued. This individual could be struggling to engage, concentrate or motivate themselves.

Similarly, decreased levels of productivity could show itself in the quality of work produced by said individual. If you notice the quality of work produced is continuously poorer than it was previously, deadlines have been missed or a normal workload is piling on top of an employee, these are all signs that there could be a bigger issue at hand.

3) Withdrawal from Social Interactions or Activities

Most workplaces will form and nurture employee relationships with social activities or days, commonly 3 or 4 times a year. Often, employees will take part in offsite team days, where they will engage in team-building interactive activities, such as a scavenger hunt, games (pool or darts), bowling or quizzes.

However, it is less heard of that someone may continuously be skipping these activities, time and time again, without reason.

If you notice withdrawn or antisocial behaviour, maybe where it once did not occur, this could signal that mental health problems are apparent. Those who are living with mental health disorders and therefore could be struggling with simple everyday tasks can sometimes be subconsciously less interested in maintaining their positive working relationships or taking time out to simply have fun or enjoy themselves.

Focused on surviving instead of thriving, it is common that those feeling mentally unwell will have a shift in priorities, and this is something to look for amongst employees.

4) Increased Absences

If an employee begins taking frequent short-term absences – such as calling in sick regularly or using annual leave in an unplanned or inconsistent way – it may indicate that they are struggling with their mental health. Difficulty maintaining consistent attendance can often be linked to low energy levels, changes in mood, increased anxiety, or feeling overwhelmed by workload.

A noticeable rise in absenteeism can be an important red flag in the workplace. Research from the Health Foundation shows that young people with work-limiting mental health conditions are significantly more likely to be economically inactive or out of employment, education, or training (NEET) compared to those without such conditions. This highlights the strong connection between poor mental health and reduced ability to engage consistently with work or study.

While taking time away from work is essential for maintaining a healthy work-life balance, employees should never feel that absence is their only option for coping with work-related stress or declining mental wellbeing.

If you begin to notice a pattern of increased or irregular absences across your team, it may point to a wider issue around employee mental health and workplace wellbeing that needs to be addressed.

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5) Skipping Opportunities to Eat Together

Eating disorders are serious mental health conditions that continue to affect a significant number of people in the UK and can have a major impact on both physical health and day-to-day functioning. It is estimated that at least 1.25 million people in the UK are living with an eating disorder, although the true figure is likely higher due to underdiagnosis and individuals not seeking support.

This means that in almost any workplace, it is highly likely that someone may be directly affected by an eating disorder or be supporting a family member or friend who is. This means it's essential for organisations to understand and prioritise mental health in the workplace as part of their wider employee wellbeing strategy.

Eating disorders can be particularly difficult to recognise in professional environments. Many individuals continue to function at a high level, and traits such as perfectionism, strong attention to detail, and high achievement – often valued in the workplace – can sometimes mask underlying difficulties. 

However, these behaviours may also be linked to a need for control, which is commonly associated with eating disorders.

Because of this, employers and colleagues should be aware of potential workplace mental health warning signs, which could include:

• Increased anxiety, irritability, or distress around meal breaks
• Preoccupation with food, dieting, body image, calories, or exercise
• Avoidance of social situations involving food (e.g. team lunches or meetings)
• Strict or rigid routines around eating or physical activity
• Increased caffeine use or reliance on stimulants for energy or appetite control
• Difficulty concentrating, fatigue, or reduced performance
• Noticeable changes in physical appearance, energy levels, or mood

If you are concerned that someone in your workplace may be struggling with an eating disorder, it is important to approach the situation with sensitivity and care. Early intervention and support can make a significant difference to an individuals recovery. 

6) General Feelings of Doubt, Fear, and Anxiety

While quite a broad mixture of feelings, it is important to look out for repeated signs of stress, anxiety and low mood amongst employees – especially in both hybrid and remote workplaces. While it is normal to have both good and bad days at work, if someone is repeatedly stressed, anxious and presenting a genuine fear of speaking up amongst their peers, there might be a more underlying issue at hand.

Feeling psychologically safe in the workplace has become a much talked-about subject during the last few years, as employees are becoming more aware of both how they should be treated in their workplace and how they are treated.

To be psychologically safe is to know that collectively in the workplace, you can make mistakes, express your ideas and concerns and take risks, with no fear that you will essentially be punished, scrutinised or belittled for your input. If an employee is not feeling psychologically safe in their role, it can present in the following ways:

• Lack of participation in team meetings
• Lack of confidence or belief in ability
• Consistently apologising after any input or suggestion
• Feelings of defensiveness, self-criticism and self-blame

Knowing the signs of what to look for allows managers and senior staff to better support their employees, building a workplace in which they feel empowered and motivated.

Mental health can present itself in several different ways, both inside the workplace and out. While the stigma around mental illness and conditions is reducing, workplaces still require more training, resource and equipment to enable them to better support their workforce.

It is with further development of policies, training, tools and materials that employers continue to work towards creating a workplace in which employees feel they can bring their whole selves to work, feel correctly supported and encouraged to grow, regardless of their mental health.

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