Seasonal Affective Disorder (SAD), also known as a Depressive Disorder with Seasonal Patterns, usually occurs during the fall and winter months. SAD occurs when a person experiences a “recurrent major depressive episodes with regular seasonal patterns.1 Although SAD is no longer an official diagnosis, the SAD diagnosis can be made if the following criteria are met:
- There has been a relationship between the onset of a major depressive episode at a specific and recurring time of the year.
- Full recovery, or a change from depression to mania, also occurs at a particular time of the year.
- In the previous two years, two major depressive episodes occurred that demonstrated the temporal seasonal relationships. No non-seasonal depressive episodes have occurred during the same period.
- The seasonal major depressive disorders substantially outnumber the non-seasonal major depressive episodes that may have occurred over an individual’s lifetime.
- The lifetime prevalence rate of SAD in Canada is 1.7-2.9%.1
- People with SAD make up about 10% of all cases of Depression.
- After the age of 50, the probability of experiencing SAD decreases.3
- Women may be up to nine times more likely to be diagnosed with SAD than men.3
- Fifteen percent of people will experience mild SAD that does not cause major life disruptions.3
- Thirteen to seventeen percent of people who develop SAD have an immediate family member with the disorder.3
Behaviours associated with SAD:
- Eating more sugary and starchy foods during the winter months
- Ignoring invitations to join family and friends during the holidays
- Staying in bed and crying during the daytime
- Fighting with others during the summer due to the heat and irritability
- Turning down invitations to summer barbeques because you have no appetite
Feelings associated with SAD:2
Thoughts associated with SAD:
- “There is no point in living; everything is so dark and gray.”
- “I wish everyone would just leave me alone.”
- “I really should be outside. I am wasting my life.”
- “I know I should clean the house, but there is no way I can get out of bed today.”
SAD and the Body:
The physical effects of SAD include:2
- Weight gain or weight loss
- Insomnia (difficulty sleeping) or Hypersomnia (sleeping too much)
- Cravings for carbohydrates
- Slow movements
- Low energy
SAD and the Brain:
There are several theories about the neurobiological causes of SAD. Researchers have found that neurotransmitters are heavily involved in SAD, including serotonin, dopamine, and norepinephrine. Studies have shown that levels of serotonin fluctuate across the seasons, especially in the hypothalamus. In the hypothalamus, serotonin is involved in determining when the body is hungry and full, and its levels are lowest during the winter months.4 This finding helps explain why the appetite changes and carbohydrate cravings occur as a feature of SAD. The relationship between norepinephrine and SAD is evidenced in the symptoms of hypersomnia and increased eating.4 Norepinephrine, which is related to arousal, is found in lower levels in people with SAD. The hypo-arousal symptoms of SAD, including hypersomnia and increased eating, point to the involvement of norepinephrine. Researchers also suspect that lower dopamine levels contribute to SAD symptoms. Dopamine is one of the main neurotransmitters involved in responding to light levels, and lower levels of dopamine may cause a reduction in the eyes’ light sensitivity.4 Premenopausal women are especially affected by dopamine when it comes to SAD, evidenced by their positive response to dopamine therapy.4
Does Psychology Work?
- Cognitive Behavioural Therapy (CBT): CBT is a type of psychotherapy that can help treat SAD by teaching clients to change negative thoughts and disengage in behaviours that make their conditions worse. Studies of CBT show that when the treatment plan is designed to specifically target SAD, it can reduce the adverse symptoms and help prevent future relapses. Some evidence suggests that CBT and BIT are equally effective, but others show that CBT is a superior treatment. In one study, no participant who underwent CBT experienced a full relapse in SAD symptoms, compared to the 60% of participants who relapsed after receiving light therapy alone.
Tips to Manage SAD!
- Let the Light In: When the sunlight is scarce, it can be difficult to get enough of it to keep your biological clock running smoothly. Sunlight exposure has been shown to improve symptoms of SAD, and there are various ways to get more during the winter months. Some of these strategies include:
- Keeping curtains open
- Moving furniture closer to the windows
- Taking a brief walk during the daytime.
- Buy a special Light Therapy Machine: This type of therapy involves sitting in close proximity to a specialized light source that produces a specified amount of light.2 Multiple studies have shown that Light Therapy can significantly reduce symptoms of SAD by up to 40%. Morning light therapy has proven to be more effective than light therapy administered during the evening or nighttime.8 In comparison to certain medications, Light Therapy has performed equally as well for reducing SAD symptoms.2 One study found that Light Therapy produced positive results more quickly than pharmacological interventions.2 Over 60 studies have verified that Light Therapy is an effective treatment for SAD.
- Get more Exercise: Preliminary studies have shown that physical exercise can perform as well as BLT for the treatment of SAD.2 Although it is challenging to begin an exercise regimen, especially with low energy, the benefits may be worth the initial difficulty.
- Dietary Changes: While giving into carbohydrate cravings might momentarily alleviate symptoms of SAD, eating a balanced diet can positively interfere with neurotransmitter levels. Foods such as poultry, tuna, salmon, spinach, carrots, sunflower seeds, and whole grain flour can help increase levels of serotonin.
Experiencing the symptoms of Depression at any time can be challenging. Having yearly episodes of SAD can be discouraging, and anticipating the symptoms may put a damper on the rest of the months. Every person experiences SAD differently, and your symptoms are legitimate even if they differ from those in this article. Oftentimes, multiple mental health disorders can occur at the same time, such as Anxiety and Depression. At Hopewell Psychological, we have the experience and compassion to address multiple concerns and build upon your strengths. We provide treatments that are backed by research and can offer you many options to match your preferences. Individual counseling is available, as well as sessions for families, couples, and groups to improve interpersonal relationships. SAD is a complex issue, and the guidance of a Hopewell Psychologist can aid you in finding freedom from the troubling symptoms.
*Psychologists are covered under Insurance Companies in Canada. You will need to check with your insurance company about the specific details regarding your coverage.
 Westrin, A., and Lam, R. W. “Long-Term and Preventative Treatment for Seasonal Affective Disorder.” CNS drugs 21.22 (2007): 901-909.
 Westrin, A., and Lam, R. W. “Seasonal Affective Disorder: A Clinical Update.” Annals of Clinical Psychiatry 19.4 (2007): 239-246.
 “Seasonal Affective Disorder.” Canadian Mental Health Association. CMHA, British Columbia Division, 2013. Web. 21 May 2017.
 Lam, R. W., and Levitan, R. D. “Pathophysiology of seasonal affective disorder: a review.” Journal of Psychiatry and Neuroscience 25.5 (2000): 469-480.
 Evans, Maggie, et al. “Cognitive Change across Cognitive-Behavioral and Light Therapy Treatments for Seasonal Affective Disorder: What Accounts for Clinical Status the Next Winter?” Cognitive Therapy Resources 37.6 (2014): 1-21.
 Rohan, K. J., et al. “Cognitive-behavioral therapy, light therapy, and their combination in treating seasonal affective disorder.” Journal of Affective Disorders 80.2 (2004): 273-283.
 Rieder-Praschak, N., and Willeit, M. “Treatment of seasonal affective disorders.” Dialogues in Clinical Neuroscience 5.4 (2003): 389-398.
 Shabbir, F., et al. “Effect of diet on serotonergic neurotransmission in depression.” Neurochemistry international 62.3 (2013): 324-329.