Seasonal Affective Disorder: An Introduction

As the days grow colder and shorter, and the nights grow longer during the transition from summer to the autumn and winter period, it is unsurprising that people experience a worsening in how they feel. As individuals from House Stark like to say – “Winter is coming”.  

Seasonal Affective Disorder is quite common – studies have found that about 5% of the U.S. population experiences seasonal affective disorder, with symptoms present about 40% of the year (Kurlanski & Ibay, 2012). However, I expect that a much more significant number experience a general reduction in mood (though perhaps not meeting diagnostic criteria).

When thinking from a cognitive behavioural therapy perspective, there are certain environmental and behavioural changes that occur that is likely to affect mental health.

In this post, I provide a few hypotheses on why changes in seasons are leading to issues with mood and sleep. Importantly, I’ll also provide a few CBT strategies for depression and insomnia that might be helpful to stave off seasonal affective changes.

Seasonal changes and depression

The change in seasons leads to shorter and colder days. With these changes, the result is a lot less light activity and our days become a lot more empty. Both of these changes can impact our mood.

In summer, we are often a lot more active in our daily lives: we may spend more time outside; exercise more often; hang out with friends, among other reinforcing activities. The reduction in activities in our lives during the seasonal shift reduces the amount of positive reinforcement in our lives, which can impact our mood. Moreover, energy is like a generator, rather than a battery. Therefore, we may also feel more fatigue as a result of the reduction in activity. Both of these factors make us feel worse for wear.

Second, the lack of light exposure can lead to a general reduction in mood. Light activity is associated with mood (Dumont & Beaulieu, 2006) and the lack of light exposure could be a contributing factor to depressive symptoms.

Woman getting light exposure

Seasonal changes and sleep

Depression and sleep are very related. Factors that impact our mood can impact our sleep (and vice versa).

Importantly, the reduction in activities in a person’s day can reduce the build-up of sleep pressure. Sleep pressure is what provides us the deep and refreshing sleep that we need. Without sufficient build-up, our sleep pressure dwindles, and our sleep becomes light and unrefreshing. Poor sleep can of course lead to poor mood. Secondly, the lack of light exposure may also be impacting our circadian rhythm. Our internal clock plays a big role in pretty much every area of our physiological functioning. Light is the primary factor that helps synchronize our clock and the lack of light can impact our body’s ability to regulate our sleep/wake cycle. We may also be more inclined to sleep-in, which can lead to more REM (rapid eye movement) sleep – this is associated with depressive symptoms

CBT strategies to combat seasonal affective disorder

Now that we have talked about causes of mood and sleep issues in seasonal affective disorder, here are a few CBT strategies that may be helpful to support a proper transition into the wintery times.

1. Schedule activities into your daily life. Although certain activities, like going to the beach, may be somewhat limited due to inclement weather, adding season-appropriate activities into your life can increase the amount of positive reinforcement in your life. Activities could be something small (e.g., making yourself a nice coffee in the morning or taking a warm bath) to something more active (e.g., doing yoga, taking a 15 minute walk on a treadmill). The latter examples have the added benefit of increasing our sleep pressure, which can be very helpful to stave off problems with sleep and increase our sleep quality. Here’s a post on scheduling activities in your life if you are interested!

Drinking coffee while reading a book

2. Wake up at consistent times. Getting out of bed at a similar time every day can be a great way to set our circadian rhythm and ensure that we are not experiencing symptoms of jetlag and low mood resulting from a poor sleep schedule.

3. Getting regular exposure to light. Although opportunities for light exposure aren’t as plentiful, taking actionable steps to get some light in the morning and throughout the day can be helpful to improve our mood. In some cases, some people may find benefits using a light box to increase exposure to light activity, though research is limited (Nussbaumer et al., 2015).

4. Increasing social support. Look for opportunities to spend time with friends and family can be a protective factor for mood. Although opportunities for outdoor activities may be challenging, there may be other ways to engage with loved ones (e.g., phone calls, house gatherings, lunches, movies) to support mood and wellbeing.

5. An acceptance approach. Given all these changes, it makes a lot of sense that we don’t feel at our best all the time. Taking a mindful attitude to the natural changes in our mood can be helpful to protecting ourselves from a depressive spiral. What we resist, persists. However, if we accept the fact that sleep and mood might take a small hit (while also doing our best to reduce this as much as possible), we are much more likely to handle this transition well.

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Best wishes,