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What is Seasonal affective disorder (SAD)?

Seasonal affective disorder (SAD), also known as seasonal depression or winter depression, is a form of depression that comes and goes with the seasons. The Diagnostic Manual of Mental Disorders (DSM-5) identifies SAD as a type of depression known as major depressive disorder (MDD) with a seasonal pattern.

Symptoms of this recurrent form of depression become worse in the late autumn or early winter before going away as the days grow longer and brighter in the spring or summer. While most people are more likely to experience SAD in winter, some people can experience it in reverse, during the spring or summer, although this is rare.

SAD is more than a case of the “winter blues” because the symptoms can be severe and even debilitating for many people. Seasonal affective disorder differs from major depressive disorder in that MDD occurs throughout the year and does not depend on seasonal change.

What are the symptoms of Seasonal Affective Disorder?

As with other kinds of depression, a person with SAD may notice any or all of the following symptoms:

• Feeling listless, sad or down every day
• Feelings of despair, guilt and worthlessness
• Sleeping for much longer than normal and finding it difficult to get up in the morning
• Gaining weight which may be tied to cravings for sweet and starchy comfort foods
• Losing interest in activities you once enjoyed, including withdrawing from people.
• Difficulty concentrating
• Lack of energy and extreme fatigue even though you may be sleeping a lot more than normal
• Feeling anxious and irritable
• Being more prone to physical health problems, such as colds, infections or other illnesses
• Physical problems, such as headaches
• Suicidal feelings

Diagnosing SAD

If you feel depressed for days at a time, can’t get yourself to carry out normal activities, and your sleep patterns and appetite have changed, it’s important that you see your doctor. To diagnose SAD, your doctor will conduct a physical exam, as well as a psychological exam to check for signs of depression.

Your doctor will look for seasonal patterns, such as depression that begins and ends during specific seasons every year, and no episodes of depression during the season in which you experience a normal mood.

What causes SAD?

While the exact cause of SAD is not fully known, the condition is often linked to lack of sunlight during the shorter autumn and winter days. It is thought that shorter days and less daylight may trigger a chemical change in the brain leading to symptoms of depression.

Researchers have linked SAD to several potential causes:

• Biological clock change: Your biological clock regulates your mood, sleep and hormones. When there’s less sunlight, you’re out of step with the daily schedule you’ve been used to and you find it difficult to adjust to changes in daylight length.
• Serotonin: Exposure to sunlight is thought to release the production of serotonin in your brain, which contributes to feelings of happiness. Decreased sun exposure has been associated with a drop in your serotonin levels in the winter which can lead to seasonal affective disorder depression with seasonal pattern.
• Vitamin D deficiency: Because sunlight helps produce vitamin D, less sun in the winter can lead to a deficiency, which can affect your serotonin level and your mood.
• Melatonin boost:  Melatonin effects your sleep patterns. The lack of sunlight in autumn and winter can stimulate an overproduction of melatonin, making you feel sluggish and sleepy.

Risk factors for SAD

Some of the risk factors for SAD include:

• Living too far North or South of the equator: If you live in areas that have long winter nights and less sunlight, you are more likely to experience SAD. For example, the condition is more common in places like Canada and Alaska and it’s less often found where there’s plenty of sunshine year-round, like Florida.
• Family history: SAD is more likely to run in families. People with a family history of SAD and other mental health conditions are at greater risk of developing the condition.
• Being female: SAD occurs more frequently in women than men. Women are diagnosed with the condition nearly four times as often as men
• Younger age: Although SAD can happen at any age, it most often begins in younger adults between ages 18 and 30. Children and teens have been diagnosed with the condition as well.
• Depression or bipolar disorder: People with other mental health conditions are more likely to experience SAD. Around 25 per cent of people with bipolar disorder and between 10 to 20 per cent of people with major depressive disorder also have SAD.

Treatments for SAD

A range of treatments are available for seasonal affective disorder. Your doctor will recommend the most suitable treatment programme for you, depending on how severe your symptoms are. Keep in mind that it may take a combination of approaches to manage the condition.

Light therapy 

Light therapy involves sitting in front of a special lamp called a light box for about 30 minutes each day, and treatment usually continues from the time of year that symptoms begin and lasts throughout the winter months. The light from the box mimics natural sunlight and can help improve mood.

Light therapy has been shown to be effective in up to 85 per cent of SAD cases. Starting light therapy before the onset of symptoms in the autumn may even help prevent seasonal affective disorder.

Although side effects are rare, they can include blurred vision, headaches and eye strain. Avoid using the light in the evening as this can disrupt sleeping patterns by tricking your brain into thinking it’s daytime. The best time to use light therapy is in the morning.

Dawn simulation is another effective form of light therapy. Dawn simulators are like alarm clocks except that they use light instead of sound. Similar to sunlight, a dawn simulator comes on dimly about an hour before waking up time and gradually get brighter. 

Cognitive behavioural therapy 

Cognitive behavioural therapy (CBT) is a technique that alters negative thoughts to manipulate emotions and behaviours, like changing your thinking from “I hate winter” to “I prefer summer.” Because the focus is simply on proactively coping with wintertime, studies indicate that CBT may provide longer-term benefits as opposed to other treatments for SAD.

• Antidepressant medicine: Traditional antidepressants such as selective serotonin reuptake inhibitors (SSRIs) are often used to treat seasonal depression. SSRIs work by increasing serotonin levels in the brain.
• Seek out the sun: Getting as much natural sunlight as possible can help improve your symptoms. Try to get out during the day, and for at least 20 minutes every afternoon, when the sun is at its brightest. When you are indoors, sit near a window, and open the blinds or curtains to let in as much natural sunshine as possible.
• Vitamin D: A recent study found a link between SAD and low vitamin D levels. Vitamin D levels decline in winter due to a decrease in outdoor daylight exposure. A vitamin D supplement may help improve your symptoms.

10 Tips to ease your SAD symptoms

It can be difficult living with Seasonal Affective Disorder, but there are things you can do to help yourself.

• Spend more time outdoors during the day.
• Avoid sitting in dark or dimly lit rooms. Try to arrange the spaces you spend most time in to maximise sunlight
• Add lamps and mirrors to brighten up anywhere that is particularly dark, and keep curtains open during the day.
• Cut back any tree branches or hedges that may be blocking the light from getting into your home.
• Rearrange furniture in your home so you are sitting near a window or, if you exercise indoors, set up your exercise equipment by a window.
• Build exercise into your lifestyle, preferably before SAD symptoms take hold. Exercise in general is beneficial, even when it’s indoors. Aside from daily walks, try strength training or yoga.
• Take a winter holiday to a sunny climate. Pack a swimsuit, grab a good book and head to a location where you can get all the natural sunlight you need.
• Bring the outside in by having lots of plants around your home. Looking after pot plants can help to lift a low mood.
• Aromatherapy and aromatherapy massages can help promote rest, reduce stress, stimulate your immune system and brighten your mood.
• A diet rich in unprocessed foods, proteins (lean meats, seafood), vegetables, fruits, and complex carbohydrates can protect against mental health disorders. Avoid high-sugar foods such as refined grains, pasta, soft drinks, and processed foods with added sugar.

If you think you have Seasonal Affective Disorder, it’s important to seek help and advice from a medical professional to rule out other explanations for your symptoms. Your doctor can work with you to create a treatment plan to best manage the condition. With the right help, most people with SAD can control their symptoms and make the most of the winter season.

At Nextcare, our mission is to keep you well. Whether you need help, advice or support, check our Telehealth service to get personalized advice to maintain or improve your health and wellbeing. You can access our Telehealth service on our Lumi App.