About Workplace Mental Health
The summer effect is real
Most people feel better in summer. Energy tends to be higher, mood tends to be lighter, and the experience of work, while unchanged in most of its fundamentals, tends to feel more manageable. The reverse pattern in winter is equally well-documented. Lower energy, increased difficulty concentrating, a heavier quality to everyday tasks, a greater susceptibility to low mood.
For a significant proportion of the population, this seasonal variation crosses from the ordinary into the clinical. Seasonal Affective Disorder, SAD, affects around one in fifteen people in the UK. Sub-syndromal SAD, sometimes called the winter blues, affects a considerably higher proportion, with some estimates suggesting around one in five people experience meaningful seasonal changes in mood and function, short of clinical threshold but still significant in their impact on daily life and work performance.
What is actually happening biologically
The primary mechanism is light. In winter, the number of daylight hours decreases, and the quality of light changes. Many people commute to work before sunrise and leave after sunset. They spend their working hours in artificial light environments that do not replicate the intensity or spectrum of natural daylight.
This matters because light is the primary cue that regulates the body’s circadian rhythm, the internal clock that governs sleep, waking, hormone release, and mood. Insufficient light exposure disrupts melatonin regulation and is associated with reduced serotonin activity. The result is the cluster of symptoms many people recognise: fatigue, a need for more sleep, carbohydrate cravings, difficulty concentrating, and low mood.
The workforce impact
The effects of seasonal mood change on workforce performance are not trivial. Reduced concentration, lower energy, decreased motivation, and increased irritability affect the quality of work, the quality of relationships at work, and the likelihood that individuals will seek help if they are struggling. Absence rates for mental health-related conditions show a consistent seasonal pattern, rising through winter and into early spring.
What employers could do that would actually help
Flexible start and finish times have a real impact on light exposure. Allowing employees who can do so to shift their working day even slightly can mean the difference between commuting in darkness and commuting in daylight. This is not a large operational change for many roles, but the effect on daily light exposure can be meaningful.
Office lighting is worth reviewing. Standard office lighting often falls well short of the intensity associated with circadian regulation. Providing access to higher-intensity lighting in break areas, or in roles with limited access to windows, is a low-cost adjustment with evidence behind it.
Physical activity support during winter is more important than during summer, not less. The instinct to reduce activity in winter, driven by weather and reduced daylight, is exactly the wrong response to what the body needs. Employer policies and facilities that make it easier to maintain physical activity through winter months are directly relevant to mental health.
Addressing social isolation matters particularly for remote workers. The combination of winter weather and remote working creates conditions where people can go for extended periods with minimal meaningful social contact. Proactive check-ins, hybrid arrangements that bring remote workers into contact with colleagues, and explicit attention to the social dimension of work are not soft options. They are proportionate responses to a real risk.
A note on what not to do
The December ‘be kind to yourself’ newsletter is not a winter mental health strategy. Neither is a single webinar about SAD. The risk of seasonal wellbeing content is the same as the risk of all awareness-only approaches: it generates visibility without generating substance, and it can create an impression of organisational concern that substitutes for the structural response that would actually make a difference.
The simplest question
At some point in November or December, ask this question about your organisation: would an employee who is struggling with low mood and low energy in winter find it easier or harder to cope because of how they work here? The answer tells you what you actually need to do.
About Peter Kelly and Being Real
Peter J Kelly is an occupational psychologist with more than 20 years at the Health and Safety Executive shaping national policy on workplace mental health. He was a member of the ISO 45003 drafting panel, the world’s first international standard for psychological health and safety at work. Being Real is his specialist consultancy, helping organisations move from policy to practice.
If you would like to talk about what real support looks like in your organisation, contact Peter at being-real.co.uk