Good Question: Is it the ‘winter blues’ or depression?

As the days get shorter and the weather turns colder, many people notice that their mood dips along with the temperature. Feeling a little sluggish or unmotivated at this time of year isn’t uncommon – research suggests that 15 percent of Canadians experience mild seasonal mood changes, while about 2 to 3 percent develop seasonal affective disorder, or SAD, a type of depression.¹ Shorter daylight hours can disrupt sleep, lower serotonin levels, and make it harder to stay active and social – all factors that negatively impact mental health.

“A lot of people tend to hang on through the holidays,” says Dr. Nadia Aleem, a psychiatrist with Cleveland Clinic Canada, which is Manulife’s medical director for group benefits. “Then come January, when they get back to their routines and life demands, they recognize that they aren’t coping or functioning well and may need additional support.”

Dr. Aleem: Seasonal mood changes are very common, especially the change from summer to fall/winter.

There are biological and behavioral reasons why these mood changes occur. From a biological perspective, in winter months we are exposed to reduced daylight, which in turn can disrupt circadian rhythms, melatonin regulation, and serotonin levels – leaving you tired, irritable and less interested in your usual activities.

In terms of behaviour – especially in regions where the temperature changes dramatically – people tend to be less active and spend less time outdoors, which further disrupts biological mood regulation systems. For many people, December additionally brings holidays and celebrations. While this time of year can be enjoyable for many, it can also be stressful and lonely for some.

Dr. Aleem: Winter blues and seasonal affective disorder (SAD) are two conditions on the same spectrum. With winter blues, the mood symptoms and functional impairment don’t last as long and are less severe than with seasonal affective disorder. SAD is a formal psychiatric diagnosis, a subtype of depression, which is listed in the DSM-5, the manual that clinicians use to diagnose and classify depressive disorders. ² SAD symptoms of depression are severe enough that day-to-day functioning is impaired. “Winter blues” is a social term rather than a formal diagnostic specification; it denotes a less severe, often fluctuating mood change that does not necessarily cause the same level of impairment as SAD.

If you have winter blues, you may experience lower mood and motivation, changes in sleep, and crave carbohydrates more than usual, but you’re still able to go about your daily life. With SAD, on the other hand, you may experience a more sustained drop in your mood and motivation that may interfere with your ability to function normally. You’re not seeing friends, you may struggle to maintain your household and personal obligations, and you may struggle to meet the demands of work.

Dr. Aleem: The first step in being able to address your symptoms is being able to recognize when you're struggling. There are some self-tracking tools that can help. I like the Mental Health Continuum Model ³ as a monitoring tool. In this model, mental health states are colour‑coded: green for good mental health (when you feel you are thriving), yellow for more challenging periods, and red for signs of illness. We each have personal signs, symptoms, and functional changes that signal wellness or illness. For instance, when I am struggling, my sleep and sense of humour are the first to be compromised.

Maintaining wellness behaviours – consistent sleep, regular physical activity, and social connection – is particularly important during the winter months, especially if you notice you’re struggling or tend to experience a seasonal dip in mental health. This often requires being deliberate: prioritizing your wellness and setting boundaries on your time so you can sustain these habits. Exposure to morning light is also very important for both treatment and prevention of SAD and winter blues. Lights used for winter blues and SAD are bright, full-spectrum light boxes (SAD lamps) that mimic natural sunlight to adjust brain chemistry, typically providing 10,000 lux of light for 30-45 minutes in the morning, filtering out UV rays to improve mood, energy, and sleep.

Ideally, support comes into play before things feel overwhelming. Employer benefits – including EFAP (Employee and Family Assistance Program) – can be a good starting point. And you might find a proactive check‑in or coaching‑style session helpful even when you are in the green zone to reinforce wellness behaviours.

Dr. Aleem: One helpful practice might be setting aside a minute or two each day for a quick green-yellow-red check-in. Staying consistent with sleep and exercise can also support mental health. Studies have noted that decreased physical activity is correlated with increased reported rates of depression, ⁴ so try to keep up with your routines, ideally outside if you can brave the cold. Even when it’s cloudy, you can still get the benefits of fresh air and Vitamin D.

If that isn’t enough, light therapy is another option. SAD lamps are available without a prescription, and a half-hour blast in the morning can go a long way. Small habits, like keeping blinds or curtains open and sitting near a window while working can also offer a boost.

Winter often arrives before we feel ready. But noticing how you’re feeling, staying active, and reaching out for support early can make the season easier to navigate. Taking a proactive approach can help you feel more like yourself – no matter the time of year.