Motivation and emotion/Book/2024/Seasonal affective disorder

Seasonal affective disorder:
What is SAD, what are its causes, and how can it be treated?

Multimedia presentation (3 min)

Overview

SAD Scenario: Stacey is a 20-year-old university student. Since she started high school, she has noticed a pattern of her mood and behaviour that she can’t seem to shake. When Winter starts, she finds it hard to get out of bed and find motivation to do anything, she secludes and isolates herself because she can’t find the energy to socialise with her peers or family. She has also noticed that her grades and school attendance tend to be worse in the colder months. She has been talking to her psychologist who thinks she may have major depressive disorder with a seasonal pattern, or seasonal affective disorder (SAD).

Figure 1. changes in weather conditions is commonly attributed to be a contributing factor of SAD.

Seasonal affective disorder (SAD) is a mood disorder, characterised by a cyclical pattern of symptoms that align with season changes, symptoms occur at a specific time each year with full remission at other times in the year (Chen et al., 2024; Melrose, 2015). The fifth and most current edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM5) categorises it as a subtype or qualifier of major depressive disorder or bipolar I or II disorder (American Psychiatric Association, 2013). The most common form of SAD is autumn/winter, wherein symptoms start manifesting with the onset of colder weather at the start of Autumn and persist throughout Winter, but then reduce in intensity and frequency as the weather warms at the start of Spring reaching full remission for Summer (APA, 2013), hence why it is commonly referred to as "Winter blues" or "Winter depression" (Nevarez-Florez, 2020; Melrose, 2015). Increased frequency of rain and/or snow weather events as pictured in Figure 1 as well as lower temperatures and higher wind speeds are attributed to be contributing factors to Autumn/Winter SAD (Brazienė, 2022). It is less common but still possible to experience this in reverse, around 10% of those experiencing SAD experience the onset of symptoms in Spring/Summer and remission in Autumn/Winter (Melrose, 2015).

SAD effects an estimated 5-10% of the general population, research indicates that risk of SAD is higher for more northern latitudes as it is observed more frequently in the northernmost countries and becomes more sporadic closer to the equator and in southern latitudes (Nevarez-Flores et al., 2023).

The pathophysiology is still largely unknown, although it is believed to correlate with circadian rhythms and light exposure as well as...

Theory and research explains SAD as...

Key points: The difference between SAD and depression or bipolar is the relationship between the time of the year/season and the onset and remission of symptoms. SAD is a common disorder, evidence suggests that geographical location contributes to the prevalence of the disorder, a positive relationship between higher latitudes and rates of SAD has been observed globally. While the actual physiology of the disorder is unknown, it’s theorised that one of the causes is a daylight exposure, most non-medicinal SAD treatments aim to combat this deficiency.

Focus questions: What is SAD? What causes SAD? How can SAD be treated?

What are the signs and symptoms of SAD?

Because the DSM5 considers SAD to by a specifier of depression and bipolar I and II, the symptoms have been clinically defined as depressive, manic or hypo-manic episodes. The difference between depression without a seasonal pattern is that these episodes are experienced at the same time each year, and either full remission or transformation of the episode happens at another time each year. The essential defining feature of SAD is the temporal correlation between the time of year and when/how symptoms manifest. To be diagnosed with SAD or a mood disorder with a seasonal pattern, symptoms must manifest recurrently for at least two years (APA, 2013).

In conjunction with the clinical symptoms of depressive, manic and/or hypo-manic episodes, individuals experiencing SAD can also experience symptoms of hypersomnia, increased appetite, carbohydrate cravings, and profound fatigue (Chen, 2024)

Key points: 1 2 3

What is the psychological explanation of SAD?

Psychological theories try to ascertain the causes of SAD to help negate or reduce its effect. These theories informed treatment methods used to combat the symptoms of SAD. The most prominent explanation/theory for SAD is the change in the amount of available sunlight at different times of the year is the root cause of SAD.

Daylight and circadian rhythms

It is theorised that the amount of available sunlight in a season affects the brain's ability to produce and regulate neurotransmitters and hormones. Specifically, SAD is related to transmission of serotonin and overproduction of melatonin.

Behavioural changes and routine interruptions

Some evidence has been found that suggests that the changes in routine and daily experiences and comfort levels change with the seasons. With this is mind for Autumn/Winter SAD, weather events like snow and rain can happen more frequently, which can make commuting and spending time outdoors less comfortable for some. In more extreme cases, weather like this can also effect transport and other aspects of day-to-day life. Lower temperatures also call for more or warmer clothes, and extra financial expenses (e.g., heating a home) can increase stress and initiate SAD symptoms. Similarly in Spring/Summer SAD, weather events like droughts and bushfires, cause extra stress.

Key points: The most commonly accepted theory explains the etiology of SAD to be a lack of sunlight in colder months, this thoery explains why phototherapy and bright light therapy works as a treatment but doesn't explain why some people experience Spring/Summer SAD, and get the same symptoms at the times of year with the most available sunlight. another possible explanation for SAD is that changes in season bring on changes in behaviour and routine which can make people uncomfortable or stressed. However when considering the diagnostic criteria in the DSM5 there is a note that specifies that the symptoms experienced can't be due to "seasonally related psychosocial stressors" which puts this theory into question. While some understanding about the biological processes involved in SAD exists, it's largely speculative or anecdotal, which means it's all largely theory-based.

How is SAD treated or managed?

Today, there are currently multiple different ways that SAD is treated. treatment differs based on the symptoms exhibited by the individual being treated and the type of SAD they they have (Autumn/Winter or Spring/Summer)

the most common and effective treatments are as follows

Phototherapy/bright light therapy

Bright light therapy is an effective treatment of SAD and has been used for over 30 years (Pjrek et al., 2020). The treatment involves exposing a subject with SAD to a bright light and is used mostly in Autumn/Winter SAD in an attempt to negate the effects of a lack of natural sunlight.

Cognitive behavioural therapy

Cognitive behavioural therapy (CBT) is a form of psychological treatment that is based on the principles that psychological disorders and problems are rooted in learned behaviour and maladaptive thought patterns and that symptoms can be relieved by relearning helpful and healthy ways of thinking and behaving. The approach is applied liberally across most psychological disorders, and has been found to be especially effective at negating symptoms of depression and anxiety (Gaudiano, 2008).

Medication / antidepressants

Psychiatric medications are a common treatment option for depression and bipolar I and II, and therefore also for SAD. Medications are mostly prescribed in combination with other forms of therapy...

Key points: Phototherapy and bright light therapy is used to treat Autumn/Winter SAD by increasing the amount of light that a person is exposed to during seasons where there is available sunlight. CBT is utilised to help individuals with SAD to relearn patterns of thoughts and behaviours to support a more helpful and healthy outlook and reduce the effects of their SAD symptoms. Psychiatric medications are also often utilised in combination with other forms of therapy to support them by changing chemicals in the brain to either make them more susceptible to treatment or reduce the effects of depression, mania or hypo-mania.

Test yourself

1 What does SAD stand for?

	Super Addictive Drugs
	Seasonal Affective Disorder
	Season Alert Disorder
	Sense Aversion Depression

2 Where does research suggest that SAD is most common?

	northern latitudes
	southern latitudes
	on the equator

Conclusion

SAD is a mood disorder characterised by depressive, manic and/or hypo-manic episodes that recur in a cyclical pattern at specific times each year. These symptoms are triggered by changes in seasons. The DSM5 considers SAD to be a specifier of major depressive disorder or bipolar I or II as opposed it's own disease, but some scholars and clinicians disagree. An estimated 5-10% of the general population experience SAD, evidence suggests that the risk of developing SAD is greater the further North a person lives. Research on SAD in the southern hemisphere is severely lacking compared to that of the Northern hemisphere, however SAD is still experienced, observed and studied in Australia, New Zealand and South America and other places situated below the equator. According to the DSM5, the symptoms of SAD are that of depression or bipolar, and theories suggest that possible causes of the disorder could be a lack of available sunlight in colder months a change in routine or behaviour, or another unknown that is yet to be uncovered. Treatment for SAD mainly takes the form phototherapy or bright light therapy, which combats Autumn/Winter SAD by providing exposure to light to combat the effects of light deficiency in colder months. SAD is also treated with CBT, and with psychiatric medications typically prescribed for depression and/or bipolar I or II.

Key takeaways SAD manifests in a similar way to other disorders, its main identifying feature is that symptoms occur at the same time each year, and regress or change between each of the recurrences. Most of the relevant literature calls for more longitudinal research, and on larger sample sizes to account for differences in age, ethnicity, etc. There is also lacking research about SAD in the southern hempisphere.

See also

alphabetical:

• Light therapy (Wikipedia)
• Vitamin D and emotion regulation (Wikiversity)

References

American Psychiatric Association (2023). Specifiers for bipolar and related disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596

Brazienė, A., Venclovienė, J., Vaičiulis, V., Lukšienė, D., Tamošiūnas, A., Milvidaitė, I., Radišauskas, R. & Bobak, M. (2022). Relationship between depressive symptoms and weather conditions. Environmental Research and Public Health, 19(9). https://doi.org/10.3390/ijerph19095069

Chen, Z. W., Zhang, X. F. & Tu, Z. M. (2024). Treatment measures for seasonal affective disorder: A network meta-analysis. Journal for Affective Disorders, 350(1) 531-536. https://doi.org/10.1016/j.jad.2024.01.028

Gaudiano, B. (2008). Cognitive-behavioural therapies: achievements and challenges. BMJ Mental Health, 11(1) 5-7. https://doi.org/10.1136/ebmh.11.1.5

Melrose, S. (2015). Seasonal affective disorder: an overview of assessment and treatment approaches. Depression Research and Treatment, https://doi.org/10.1155/2015/178564

Nevarez-Flores A. G., Bostock, E. C. S. & Neil, A. (2023). The underexplored presence of seasonal affective disorder in the southern hemisphere: a narrative review of the Australian literature, Journal of Psychiatric Research, 162(1) 170-179. https://doi.org/10.1016/j.jpsychires.2023.05.003

Pjrek, E., Friedrich, M. E., Cambioli, L., Dold, M., Jäger, F., Komorowski, A., Lanzenberger, R., Kasper, S. & Winkler, D. (2020). The efficacy of light therapy in the treatment of seasonal affective disorder: a meta-analysis of randomized controlled trials. Psychiatry and Psychology, 89(1) 17-24. https://doi.org/10.1159/000502891

External links

• International directory of mental health helplines (Helpguide.org)

• DSM5 (American Psychiatric Associatuon)