As the days grow shorter and the sunlight becomes more elusive, many of us feel subtle shifts in energy, motivation, and focus. For some, these changes are mild. For others, they signal something deeper – Seasonal Affective Disorder (SAD).
In this article, we explore what SAD is, how it affects cognition and executive function, and what you as an educator, therapist, or workplace professional can do to support yourself and others through the darker months.
What Is Seasonal Affective Disorder?
Seasonal Affective Disorder (SAD) is a form of depression that follows a seasonal pattern, typically emerging in autumn or winter and improving in spring or summer.
Common symptoms include persistent low mood, fatigue, oversleeping, changes in appetite (often craving carbohydrates), loss of interest, and difficulty concentrating.
SAD affects around 1 in 15 people in the UK each year (Nuffield Health, 2023), and can significantly impact wellbeing, relationships, and performance.
While mild “winter blues” are relatively common, SAD is more severe, longer-lasting, and interferes with daily functioning. A UK prevalence study found 2.4% of adults met full criteria for SAD, with many undiagnosed (Sullivan & Payne, British Journal of Psychiatry, 2001).
Why the Brain Struggles in the Darker Months
Understanding the neuroscience behind SAD helps explain why mood and executive functioning our brain’s ability to plan, focus, and self-regulate often decline during winter.
Disrupted Serotonin and Melatonin Regulation
Reduced daylight alters the brain’s production of serotonin (linked to mood) and melatonin (which regulates sleep and circadian rhythm).
People with SAD may have difficulty maintaining serotonin balance across seasons (Lam et al., CMAJ, 2015).
This disruption impacts emotional regulation, motivation, and energy — core elements of executive function.
Executive Function and Mood
Depression is known to impair executive function, including working memory, inhibition, and cognitive flexibility (Snyder, 2013, Clinical Psychology Review).
Studies also show sadness can reduce performance on executive tasks, especially when emotional regulation strategies are limited (Joormann & Vanderlind, 2014).
In winter, this means simple tasks planning lessons, managing workloads, or staying focused can feel disproportionately hard.
Weather, Daylight, and Activity Levels
A 2024 longitudinal study found that day length and temperature significantly influenced depression severity, partly through reduced physical activity (RADAR-MDD Study, 2024).
Simply put: shorter, darker days can make us less active, which in turn compounds low mood and fatigue.
Why Educators, Therapists, and Workplaces Should Care
SAD affects more than an individual’s wellbeing, it influences how people learn, lead, and connect.
In Schools:
Students may appear distracted, unmotivated, or oppositional when they’re actually experiencing low mood or fatigue.
Understanding how seasonal changes affect executive functions helps teachers respond with empathy, flexibility, and effective support.
In Therapy:
Clients might struggle with regulation, concentration, or motivation. Integrating psychoeducation about seasonal mood patterns can reduce shame and promote self-compassion.
In Workplaces:
Employees may face dips in focus and engagement, leading to reduced morale or burnout.
When leaders recognise these seasonal shifts, they can make simple adjustments, natural light breaks, flexible scheduling, open conversations, to support wellbeing and performance.
Strategies for Support
There’s no single solution for SAD, but research offers several practical approaches that help.
1. Increase Light Exposure
Morning light exposure or light therapy lamps (10,000 lux) have strong evidence for reducing SAD symptoms (Lam et al., 2015).
Encourage time outdoors or position workspaces near natural light wherever possible.
2. Promote Movement
Physical activity supports serotonin production and executive functioning. Even brief walks during daylight hours make a difference.
3. Support Executive Function Skills
Encourage use of planners, reminders, and clear routines. Breaking tasks into manageable steps supports cognitive control during low-energy periods.
4. Foster Psychological Safety
In both classrooms and workplaces, people thrive when they feel safe to acknowledge struggle. Normalising seasonal challenges reduces masking and shame.
5. Monitor and Escalate When Needed
If symptoms persist or intensify, referral to a GP or mental health professional is essential. SAD can co-exist with other mood disorders and may require targeted treatment such as CBT or medication.
Lead the Change Through Understanding
Seasonal Affective Disorder reminds us that behaviour is shaped by biology, environment, and understanding.
By recognising the signs, applying neuroscience, and leading with empathy, we can create schools, workplaces, and therapeutic spaces where people don’t have to hide their struggles; they can be supported through them.
Because when we understand the brain behind behaviour, we can be there for the people who need it most in our schools, workplaces, and communities.
Join Us Live: The Science of Seasonal Affective Disorder (SAD)
Join us for the second webinar in our Neuro Lab Series:
🗓 Tuesday 18 November
🕓 4:30 pm (UK time)
Discover the neuroscience behind SAD, how it impacts executive function skills, and practical ways to support yourself, your students, or your teams through the darker months.