15 Signs Your Colleague May Be Struggling with Mental Health
After 21 years in emergency nursing and training over 150,000 Australians in workplace health and safety, I’ve witnessed a troubling pattern. Many workplace mental health crises that end up in emergency departments could have been prevented if someone had recognised the signs of mental health issues earlier and knew how to respond appropriately.
The challenge isn’t awareness anymore—most Australians understand that mental health matters. The real gap is in practical recognition: knowing what to actually look for in daily workplace interactions, understanding when a colleague or employee needs support, and having the confidence to respond appropriately to someone struggling with mental health.
This guide will help you identify the signs that may indicate a colleague may be struggling with their mental health. Whether you’re a team member, supervisor, or senior leader, these observable warning signs can help you spot the signs that an employee is struggling—before they reach crisis point.
Understanding the Difference: Bad Days vs. Patterns
Before we explore specific signs of mental health struggles, it’s crucial to understand what we’re looking for. Everyone has bad days. Everyone experiences stress, frustration, and occasional exhaustion. These normal responses to workplace pressures aren’t cause for concern.
What matters is persistent change over time. When someone who’s typically engaged starts withdrawing consistently. When reliable performance begins deteriorating without clear explanation. When small shifts in behaviour accumulate into noticeable patterns that may indicate an underlying mental health condition.
Through our RULES framework at Mental Health Pro—Recognise, Understand, Listen, Encourage, Suggest—we teach people to identify these signs early. The first step, Recognition, relies on observing changes that persist beyond normal workplace ups and downs. Recognising the signs of mental health difficulties is the foundation of creating a supportive work environment.
The 15 Warning Signs of Mental Health Problems
1. Persistent Withdrawal from Social Interactions
One of the most common signs of poor mental health is social withdrawal. The colleague who used to join team lunches now eats alone at their desk. Someone who contributed actively in meetings becomes silent. The person who’d chat casually in the kitchen suddenly rushes past without making eye contact.
This isn’t about introversion—introverts can be perfectly engaged while preferring smaller interactions. This is about noticeable change from someone’s typical behaviour pattern. Many employees experiencing mental health issues begin isolating themselves as a coping mechanism.
What you might notice: They decline social invitations they’d previously accept, avoid group conversations, leave immediately after meetings without the usual brief chat, or seem physically present but mentally distant during team interactions. These signs often indicate that they are struggling with their mental wellbeing.
2. Declining Work Performance
When a consistently reliable performer starts missing deadlines, producing uncharacteristic errors, or struggling with tasks they’ve handled confidently for months, it warrants attention. Poor mental health at work significantly impacts productivity and quality.
Mental health conditions affect concentration, memory, decision-making, and motivation—all critical for work performance. Depression can make even simple tasks feel overwhelming. Anxiety can create paralysing perfectionism or difficulty prioritising. These are often signs of mental health struggles that shouldn’t be ignored.
What you might notice: Incomplete projects, missed deadlines, decreased productivity, increased errors, difficulty concentrating during discussions, or needing repeated explanations for straightforward tasks. When you notice an employee displaying these patterns, it may indicate an underlying mental health problem.
3. Significant Changes in Physical Appearance
While we shouldn’t judge people by appearance, dramatic shifts in personal presentation can signal internal struggles. When someone who typically maintains professional grooming becomes notably dishevelled, or when someone usually relaxed about appearance suddenly becomes obsessively particular, these changes also indicate mental health concerns.
Physical appearance changes are among the 5 signs frequently observed in people struggling with mental health conditions, as self-care often becomes difficult when someone is experiencing mental distress.
What you might notice: Wearing the same clothes repeatedly, appearing unwashed or unkempt (when this is out of character), dramatic weight changes, looking consistently exhausted, or sudden dramatic changes in style or presentation. These visible signs of mental health issues deserve compassionate attention.
4. Increased Absenteeism or Presenteeism
Both patterns matter when assessing mental health in the workplace. Some people experiencing mental health challenges take frequent sick days—often citing physical symptoms like headaches or stomach issues because mental health stigma makes it harder to be honest about underlying mental health struggles.
Others demonstrate presenteeism: physically present but mentally absent. They’re at their desk but accomplishing little, staring at screens without engaging, or starting tasks without finishing them. This is a significant sign of poor mental health at work.
In my emergency nursing career, I’ve treated countless people whose “mysterious” physical symptoms—chronic headaches, digestive problems, chest pain—were actually manifestations of unaddressed anxiety or depression. Mental or physical health symptoms often overlap, making recognition more challenging.
What you might notice: Frequent sick days (especially Monday/Friday patterns), arriving late and leaving early regularly, long unexplained absences from their desk, or being physically present but clearly disengaged. These patterns may be struggling indicators that shouldn’t be dismissed.
5. Mood Changes and Increased Irritability
Persistent low mood, unexpected emotional outbursts, or uncharacteristic irritability can all indicate someone is struggling at work. The usually patient colleague who snaps at minor issues. The optimistic person who suddenly voices hopeless perspectives. The emotionally steady person whose mood now fluctuates dramatically.
These mood changes are particularly significant when they’re inconsistent with the person’s normal temperament and persist over weeks rather than days. Mental health issues among employees often manifest through noticeable emotional shifts.
What you might notice: Tearfulness at seemingly minor frustrations, angry reactions disproportionate to situations, persistent pessimism, emotional numbness where they’d typically show normal emotional range, or dramatic mood swings throughout the day. These are common signs of mental health conditions requiring support.
6. Expressing Hopelessness or Overwhelm
Listen carefully to casual comments. “I can’t cope with their mental health challenges anymore,” “Nothing I do makes a difference,” “I don’t see the point,” or “Everyone would be better off without me” aren’t just throwaway phrases—they’re potential warning signs of serious mental health issues.
In workplace settings, these statements often get dismissed as “venting” or “having a bad day.” But when someone consistently expresses hopelessness, feeling trapped, or being overwhelmed beyond normal workplace stress, it indicates they may be experiencing depression, severe anxiety, or suicidal ideation—a serious mental health concern.
What you might notice: Frequent comments about feeling trapped or hopeless, expressing that they’re a burden to the team, dismissing their own contributions as worthless, or talking about permanent solutions to temporary problems. These verbal cues often indicate mental health difficulties that require immediate attention.
7. Changes in Communication Patterns
Communication shifts can be subtle but significant signs of mental health struggles. Someone who typically responds to emails within hours now takes days. A colleague who used to proofread carefully sends messages full of typos. The articulate team member struggles to express clear thoughts in meetings.
Mental health challenges affect cognitive function, making it harder to organise thoughts, communicate clearly, or maintain usual responsiveness. Poor mental health impacts professional communication significantly.
What you might notice: Delayed or minimal responses to communications, emails that are uncharacteristically brief or rambling, difficulty articulating thoughts clearly, avoiding phone or video calls when previously comfortable, or miscommunication that wasn’t typical before. These changes may indicate underlying mental health needs.
8. Physical Symptoms Without Clear Cause
As I learned throughout my nursing career, the mind-body connection is powerful. Anxiety manifests as chest tightness, rapid heartbeat, or digestive problems. Depression causes fatigue, headaches, and body aches. Chronic stress affects immune function. Mental or physical health symptoms frequently overlap.
When colleagues frequently mention physical symptoms—especially when medical investigations find no clear cause—unaddressed mental health concerns may be the underlying issues affecting their wellbeing.
What you might notice: Frequent complaints of headaches, stomach problems, chest pain, chronic fatigue, unexplained aches and pains, or repeatedly leaving work for medical appointments without clear diagnosis or improvement. These physical manifestations are often signs of mental health problems.
9. Increased Substance Use
In workplace contexts, this might appear as dramatically increased coffee consumption, frequent smoking breaks, or jokes about “needing a drink” to cope with the day. When social drinking comments become frequent or concerning, or when someone’s behaviour after lunch suggests they’re self-medicating, these patterns warrant attention as signs of mental health struggles.
Substance use—whether caffeine, alcohol, or other substances—often increases as people struggling with mental health issues attempt to manage anxiety, depression, or overwhelming stress through self-medication.
What you might notice: Frequent jokes about drinking or needing substances to cope, noticeable increase in smoking breaks, smelling of alcohol at work, or behavioural changes suggesting substance influence. These behaviours may indicate an underlying mental health condition requiring professional support.
10. Perfectionism or Procrastination Extremes
Both extremes can indicate mental health challenges in the workplace. Anxiety can drive obsessive perfectionism—someone spending hours on tasks that should take minutes, constantly revising work, or becoming paralysed by fear of making mistakes.
Conversely, depression or burnout can cause procrastination and avoidance. Tasks pile up because starting anything feels overwhelming, leading to last-minute panic or missed deadlines entirely. These are common signs of mental health issues affecting work performance.
What you might notice: Missing deadlines because they’re endlessly revising, expressing excessive worry about minor details, avoiding starting projects altogether, or oscillating between these extremes. When an employee displays these patterns, it may indicate they’re experiencing mental health difficulties.
11. Changes in Risk-Taking or Decision-Making
Uncharacteristic changes in judgment can signal mental health concerns. Someone typically cautious suddenly makes impulsive decisions. A usually decisive person becoming paralysed by even minor choices. Risk-taking that’s completely out of character.
Conditions like bipolar disorder, severe anxiety, or depression can all affect decision-making capacity, impulse control, and risk assessment. These changes are significant warning signs of potential mental health problems.
What you might notice: Making uncharacteristically impulsive decisions, taking unusual risks, or conversely, becoming unable to make even routine decisions without extensive reassurance. These behavioural shifts often indicate that someone is struggling with their mental health.
12. Physical Agitation or Restlessness
Anxiety often manifests physically. You might observe colleagues who can’t sit still during meetings, constantly fidget, pace unnecessarily, or seem physically tense even in relaxed settings. These are visible signs of mental health struggles.
Similarly, someone experiencing mental health issues like depression might move more slowly, speak with less energy, or seem physically weighted down. These physical manifestations are important signs to look for.
What you might notice: Constant fidgeting, nail-biting, hair-pulling, inability to sit through meetings, pacing, or conversely, movements and speech that seem noticeably slower than usual. These physical symptoms may indicate underlying mental health concerns.
13. Isolation Outside Work Hours
While you may not directly observe this, colleagues sometimes mention it: “I invited them to the team social but they said no again,” or “They used to talk about weekend plans but now they never do anything.”
When someone who is socially engaged starts isolating completely—declining all social invitations, never mentioning activities outside work, or explicitly stating they’re spending all their time alone—it can indicate depression or severe anxiety affecting their mental wellbeing beyond the workplace.
What you might notice: Consistently declining social invitations (when they previously accepted), never mentioning activities outside work, expressing that they’re isolated, or others commenting on their withdrawal from usual social connections. Social isolation is among the significant signs of poor mental health.
14. Heightened Sensitivity to Feedback
Everyone can feel defensive about criticism occasionally. But when someone who typically receives feedback constructively suddenly reacts with disproportionate emotional responses—tearfulness, anger, or self-deprecation—it may indicate they’re struggling with mental health concerns.
Mental health conditions, particularly depression and anxiety, can create heightened sensitivity, where minor feedback feels like devastating criticism and confirms negative self-beliefs. This is a common sign of mental health struggles affecting workplace interactions.
What you might notice: Tearful reactions to routine feedback, defensive responses inconsistent with their usual pattern, catastrophising minor corrections, or completely shutting down when receiving any constructive input. These responses often indicate that an employee may be experiencing mental health difficulties.
15. Direct or Indirect References to Self-Harm
This is the most serious mental health warning sign. Any reference—direct or indirect—to self-harm, suicide, or “ending it all” requires immediate attention. These comments might appear as jokes (“I should just end it all”), hypothetical statements (“Sometimes I wonder what it would be like if I wasn’t here”), or through social media posts.
Never dismiss these as attention-seeking or drama. People struggling with mental health issues often test the waters with indirect references before making direct disclosures. This is where mental health first aid training becomes critical.
What you might notice: Comments about self-harm, suicide, or death; giving away possessions; sudden interest in affairs/wills; saying goodbye to people in unusual ways; or expressing that others would be “better off” without them. These are crisis-level warning signs requiring immediate mental health support.
What These Signs Mean (and Don't Mean)
Observing one or two of these signs doesn’t necessarily indicate a mental health crisis. Context matters. A colleague going through a divorce might understandably be withdrawn and emotional. Someone caring for an ill family member might show declining performance due to exhaustion.
What matters when identifying potential mental health concerns is:
- Pattern recognition: Multiple signs appearing together
- Persistent change: Behaviours continuing over weeks or months
- Severity and impact: How significantly these changes affect the person and their work
- Divergence from baseline: How different this is from their typical behaviour
The goal isn’t to diagnose—that’s not your role, regardless of your position. The goal is to recognise when someone with a mental health condition might need support and respond appropriately. Recognising these signs is the first step toward creating a healthy workplace.
Moving from Recognition to Response
Recognising these signs of mental health issues is only valuable if you know what to do next. This is where Mental Health Pro’s RULES framework continues:
After Recognising the signs of mental health struggles, the framework guides you to:
- Understand the cultural, personal, and contextual factors that might be relevant
- Listen with empathy and without judgment
- Encourage appropriate professional help through mental health services and workplace support
- Suggest practical immediate strategies while respecting their autonomy
Having a supportive conversation doesn’t require clinical training. It requires genuine care, appropriate boundaries, and knowledge of available support services like employee assistance programmes.
Why Early Recognition Matters for Mental Health at Work
With one in five Australians experiencing mental health challenges annually, every workplace has people silently struggling. Research consistently shows that early intervention significantly improves outcomes and reduces the severity and duration of mental illness.
From an organisational perspective, the data is compelling: investing in workplace mental health creates a 2.3:1 return through reduced absenteeism, improved productivity, and better retention. But beyond the business case, recognising the signs of mental health concerns early prevents human suffering that doesn’t need to happen.
In my emergency nursing career, I’ve stood with countless distressed families who said, “I wish I’d known what to look for.” That’s precisely why recognition training matters—these signs and symptoms are observable, learnable patterns that anyone can identify with proper education to support mental health in the workplace.
Creating a Workplace Culture Where Signs Are Recognised
Individual recognition skills matter, but they’re most effective within supportive workplace cultures that prioritise employee mental health. Organisations that address mental health proactively create environments where:
- People feel safe discussing struggles without fear of judgment or career impact
- Managers receive training to recognise the signs and respond appropriately
- Mental Health Officers serve as designated first points of contact (parallel to First Aid Officers)
- Clear pathways to mental health support exist, making it easy to access counselling and support services
- Mental health is discussed as openly as physical health
- Employee assistance programmes are promoted and accessible
- Workplace wellbeing is prioritised at all organisational levels
When organisations normalise mental health conversations and create a supportive work environment, early intervention becomes the standard rather than crisis response. This transforms workplace culture to support mental health proactively.
According to a UK-based mental health charity, workplaces that invest in mental health support see significant improvements in employee well-being and productivity. Creating a productive workplace means addressing both mental and physical health needs.
Your Role in Recognition
Regardless of your position—whether you’re a frontline worker, team leader, HR professional, or senior executive—you have a role in recognising when colleagues are struggling with mental health issues.
You’re not expected to diagnose, treat, or solve mental health problems. You’re simply being observant, compassionate, and willing to have a supportive conversation or connect someone with appropriate mental health services.
That might look like:
- A genuine “You don’t seem yourself lately—is everything okay?”
- Connecting them with your organisation’s employee assistance programme
- Speaking with HR or a Mental Health Officer about your concerns
- Simply being a consistent, non-judgmental supportive presence
- Helping them access professional mental health support when needed
When many employees feel supported in addressing mental health concerns, the entire work environment improves. Supporting an employee struggling with their mental health creates ripple effects throughout teams and organisations.
Addressing Mental Health Issues in the Workplace
Mental health isn’t something that stays at home. Workplace mental health affects everyone—from frontline staff to senior leadership. Mental health issues at work impact productivity, team dynamics, and organisational culture.
Creating a healthy workplace requires:
- Education: Teaching all staff to identify the signs of poor mental health
- Support systems: Establishing clear pathways to mental health services
- Culture shift: Normalising conversations about mental wellbeing
- Leadership commitment: Leaders who support mental health openly
- Resources: Accessible employee assistance programmes and support services
- Prevention: Addressing workplace challenges that contribute to poor mental health
When organisations invest in workplace wellbeing, they create environments where people struggling with mental health concerns feel safe seeking help before reaching crisis point.
The Next Step: Building Mental Health Literacy
Recognition is powerful, but only when paired with appropriate action. If you’ve identified these signs of mental health struggles in a colleague and want to respond effectively, consider building your mental health literacy through evidence-based training.
Mental Health Pro provides nationally accredited courses that transform recognition into confident action. Our RULES framework gives you practical tools to support an employee effectively while maintaining appropriate boundaries—because recognising the signs is just the beginning of creating genuinely supportive workplaces.
Whether you’re looking to become a certified Mental Health Officer for your workplace, seeking practical skills to support your team, or wanting to build organisation-wide mental health capability, practical training empowers you to move beyond recognition to meaningful support. Our mental health first aid training equips you to spot the signs and respond appropriately.
Creating a Supportive Work Environment
When Australian workplaces are filled with people who can identify potential mental health concerns and respond appropriately, we create environments where mental health challenges are addressed early, support is readily available, and no one suffers in silence.
This isn’t just good for employee mental health—it’s the difference between prevention and crisis, between isolation and support, between watching helplessly and knowing exactly how to help someone experiencing mental health difficulties.
By learning to recognise these signs of mental health issues, understanding what may indicate an underlying mental health condition, and knowing how to support people struggling with mental health challenges, you contribute to a healthier workplace culture where everyone’s mental well-being matters.
Because mental health support shouldn’t be complicated. It starts with people like you who care enough to notice when a colleague or employee needs support, who take the time to learn the warning signs, and who respond with compassion and practical assistance.
When we all learn to spot the signs, understand what they mean, and know how to help someone with a mental health condition access appropriate support services, we transform workplaces from environments that contribute to mental distress into communities that actively support mental health and wellbeing.
That’s the future Mental Health Pro is building—one where mental health in the workplace is prioritised, where employee well-being drives organisational decisions, and where recognising the signs of mental health concerns leads to timely, appropriate support that prevents crisis and preserves both lives and livelihoods.
References
Australian Bureau of Statistics. (2023). National Study of Mental Health and Wellbeing, 2020-2022. ABS. https://www.abs.gov.au/statistics/health/mental-health/national-study-mental-health-and-wellbeing/latest-release
PricewaterhouseCoopers. (2014). Creating a mentally healthy workplace: Return on investment analysis. Beyond Blue. https://www.pwc.com.au/publications/pdf/beyondblue-workplace-roi-may14.pdf
Safe Work Australia. (2022). Code of Practice: Managing Psychosocial Hazards at Work.
McGorry, P.D. & Mei, C. (2018). Early intervention in youth mental health: progress and future directions. Evidence-Based Mental Health, 21(4), 182-184. https://pmc.ncbi.nlm.nih.gov/articles/PMC10270418/
Dewa, C.S., et al. (2014). Mental Health Interventions in the Workplace and Work Outcomes: A Best-Evidence Synthesis of Systematic Reviews. Journal of Occupational and Environmental Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC6816521/
