Seasonal affective disorder, a well-documented syndrome in northern latitudes, has limited credibility in Australia.
Seasonal affective disorder (SAD), also known as “winter depression,” refers to the recurrence of major depressive episodes (for a minimum of 2 consecutive years) during a given season, usually winter.1 Although the construct is widely recognized, 1, 2,3 the condition is not recognized as an autonomous mental disorder by current classification systems. Rather, the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes the “seasonal pattern” as a specifier of recurrent major depressive disorder4, and the International Classification of Diseases, 11th revision (ICD-11) has included “Seasonal depressive disorder” under the category of “recurrent depressive disorder” .5 As such, the validity of the construct as an individual mental disorder remains debatable, 6,7 and some suggest that the syndrome is a “temporary expression of a mood disorder rather than a specific disorder. ”8 However, the potential for the condition as a stand-alone disorder remains both due to its continued identification2,3,9,10 and the continuous inclusion of seasonal pattern specifiers in diagnostic classification systems.
Regardless of nomenclature, seasonal variations in mood and behavior have important clinical and management considerations, as reflected in the guide, especially in the northern hemisphere. For example, information on the prevention, detection, and treatment of SAD is available from the U.S. National Institute of Mental Health (NIMH), which also supports the need for research on SAD, including trials. clinicians to increase and strengthen the SAD evidence base. .11 The NIMH states that SAD can be treated with the use of light therapy, psychotherapy, antidepressants and vitamin D, either alone or in combination. In the United Kingdom, according to the National Institute for Health and Care Excellence, SAD should be treated in the same way as other types of depression.12 In Scandinavian countries, light therapy is considered the first treatment option, which can be combined with pharmacological and psychological treatment.13 In Finland, a non-governmental organization dedicated to mental health has also encouraged physical training to address SAD in addition to these methods of treatment.14
Whether seasonal mood and behavioral changes are considered clinically necessary in the Australian context is open to debate. The Royal Australian and New Zealand College of Psychiatress offers some guidance in the 2020 Clinical Practice Guidelines for Mood Disorders.15 In the “Treatments” section, the College recommends bright light therapy as to “first-line treatment for winter depression” .15 Information on SAD is also available to the public16, and some consider it a serious illness.17 However, SAD is considered rare or very rare.18, 19.
Internationally, it has been reported that the prevalence of SAD is between 1% and 10% of the population and is apparently related to latitude2. The finding on latitude agrees with the hypothesis that the appearance of SAD depends on the amount of light radiation (duration and brightness), which implies the geographical location and the length of the day are important considerations in the etiology of SAD.20 However, the “phase change hypothesis” has become the most prominent hypothesis in the etiology of SAD, with the presence of depressive symptoms in winter related to a delay in circadian rhythms in relation to with the sleep / wake cycle.21 According to these two hypotheses, which have different levels of support, the prevalence of SAD could vary between Hobart, the southernmost capital of Australia at a latitude of 42.88 ° S, with a minimum of 9:01 p.m. during the winter, and for example Melbourne and Brisbane, with 9:32 and 10:24 hours of daylight, respectively.22 However, only limited research has been conducted on S AD in Australia, with the most recent study conducted in Canberra in 2004.23 The study examined levels of seasonality and reported that 5.3% of participants (n = 398) met the criteria for the diagnosis of SAD. However, the authors acknowledged that the number of participants is likely to be overestimated due to the use of the Seasonal Pattern Assessment Questionnaire (SPAQ). In a study conducted in a suburban district of Melbourne, a more rigorous study design was used (i.e., conducted over a 2-year period, using the Beck Depression Inventory and the SPAQ), in which the actual prevalence of winter SAD was estimated at 0.3% .24 Meanwhile, the only identified study that assessed the prevalence of the disorder in Hobart, Tasmania25, reported that up to 9% of participants had experienced SAD in Hobart, Tasmania. clinical level and 24% at the subsyndromic level through the SPAQ. . In addition, the sample used in the research was made up of university psychology students25 and it is therefore unclear to what extent the findings can be generalized to the wider population.
Given the limited research on variable robustness, we consider that there is no solid basis for whether seasonal variation in mood is rare in Australia or not. Furthermore, because Tasmania, where the risk is expected to be highest in Australian jurisdictions, is only a small state, we wonder if the needs of Tasmanians may be overshadowed by voices from larger jurisdictions, with the consequent implications of equity. In turn, we argue that, given its geography, Australia has the potential to inform the SAD debate through systematic analysis and comparison of proposed theories for the pathogenesis of SAD from samples from around the world. country. In particular, can a prospective longitudinal study confirm the existence of SAD and contribute to the identification of criteria for diagnosis? Given the concerns mentioned with the SPAQ26, the study should necessarily include a structured interview and / or additional tools for the assessment of major depressive disorder (e.g., the Beck Depression Inventory). Assessment of biopsychosocial factors that may be contributing to the syndrome should also be considered to address the likely multifactorial nature of the disease, as is the case with most mental disorders.
SAD can be a major public health problem with limited recognition in Australia, but this cannot be confirmed or denied, given the inadequacies of available data, including robustness and geographic dissemination. Without data, providers and the public in turn are at the whim of popular thought leaders and / or beliefs, with people potentially not getting the attention they need. Addressing these concerns and ensuring that the needs of at least all Australians are identified, requires high-quality research on the scope of seasonal mood swings and behavior in different jurisdictions. ‘Australia, especially in high-risk locations (box). The study’s findings also have the potential to identify appropriate management practices and treatments and provide new insights.
Caixa – Research Priorities for Seasonal Affective Disorder (SAD) in Australia
Establish the existence of SAD in Australia through a series of suspicious cases
The study would include adults in Tasmania with suspected seasonal mood and / or behavioral changes, with Tasmania with a higher probability of winter SAD according to current hypotheses. In addition, the study would seek to broaden our understanding of the causal hypotheses and impacts of the disease. For each study participant, assessments will be conducted each season for 3 years and include:
- • Reference line:
- ▶ sociodemographic characteristics (including ancestry);
- ▶ Family history of mood disorders; i
- ▶ personality traits
- • Storm:
- ▶ location;
- ▶ Typical and atypical symptoms of depression assessed during a clinical interview;
- ▶ sound patterns;
- ▶ degree of exposure to daylight;
- ▶ physical activity;
- ▶ climatic conditions (eg temperature, humidity, atmospheric pressure);
- ▶ treatment used (pharmacotherapy, psychotherapy, light therapy, vitamin D, head);
- ▶ levels of absenteeism and presentism;
- ▶ melatonin level; i
- ▶ Vitamin D level
Subject to the findings of the Tasmanian study described above, establish the prevalence of seasonal mood and / or behavioral changes that meet the diagnostic criteria for a major depressive episode using a representative longitudinal study (minimum 2 consecutive years) adults from all over Australia, from Tasmania to Darwin, by local season