Blue Monday: myth, media narrative, and clinical relevance

Every January, Blue Monday is described as “the most depressing day of the year.” But while the concept lacks scientific basis, winter-related changes in mood are real.

From media myth to clinical relevance

Each year, usually in mid-January, the term Blue Monday reappears in public discourse, widely described as “the most depressing day of the year.” The concept is typically linked to a combination of factors such as cold weather, reduced daylight, post-holiday financial strain, and declining motivation after New Year’s resolutions fail. Its appeal lies in its apparent simplicity: a single date that seems to capture a widespread sense of winter-related emotional fatigue.

However, Blue Monday is not rooted in psychological or epidemiological research. The idea originated from a marketing initiative and was later popularized by the media, despite the absence of empirical data supporting the existence of a specific day associated with a peak in depressive symptoms. Over time, experts have repeatedly questioned its validity, pointing out that reducing emotional distress to a calendar event oversimplifies the complex and multifactorial nature of mood regulation.

The recurring attention given to Blue Monday nevertheless reflects a broader and more relevant issue. Winter is a period during which many individuals report changes in mood, energy levels, sleep patterns, and motivation. While these experiences are common, they do not follow a fixed temporal pattern and cannot be confined to a single day. For clinicians, the challenge is not to legitimize the myth itself, but to use its popularity as an entry point to clarify the difference between normal seasonal emotional fluctuations and clinically significant mood disorders.

Seasonality and mood: what does the evidence show?

Unlike the Blue Monday claim, the concept of seasonality in mood and behavior is well established in clinical literature, dating back to the landmark descriptions by Rosenthal et al. (1984). Numerous studies have shown that depressive symptoms, fatigue, sleep disturbances, and reduced motivation tend to increase during the winter months in a subset of the population.

Reduced exposure to natural light, changes in circadian rhythms, decreased physical activity, and social factors all play a role. Recent meta-analyses confirm that the prevalence of these symptoms is strictly correlated with latitude, reinforcing that the primary trigger is the objective availability of natural light rather than a specific calendar date (Kim et al., 2025).

However, evidence from large-scale cohort studies, such as the Netherlands Study of Depression and Anxiety (Winthorst et al., 2017), suggests that the magnitude of seasonal effects is often modest and highly variable across the population. Not everyone experiences a winter-related decline in mood, and for most individuals, these changes remain within the range of normal emotional fluctuations (Øverland et al., 2019). Importantly, longitudinal research has consistently failed to identify a specific “peak day” for depressive symptoms, further undermining the idea of Blue Monday as a biologically or psychologically meaningful event.

From winter blues to depressive disorders

From a clinical perspective, it is essential to distinguish between transient low mood and diagnosable mental health conditions. Many people experience what is commonly referred to as “winter blues,” characterized by mild sadness, reduced energy, and increased sleep. These symptoms are usually self-limiting and do not significantly impair daily functioning.

Seasonal affective disorder (SAD), on the other hand, represents a recurrent form of major depressive disorder with a clear seasonal pattern, most commonly with onset in autumn or winter and remission in spring. SAD is associated with more pronounced symptoms, including marked anhedonia, hypersomnia, carbohydrate craving, weight gain, and functional impairment. While SAD affects only a minority of individuals, it is a well-defined clinical entity and should not be conflated with generic winter discomfort or media-driven concepts such as Blue Monday.

The risks of oversimplification

One of the main problems with the Blue Monday narrative is that it oversimplifies mental health and may inadvertently trivialize depression. Presenting sadness as something that is expected, or even inevitable, on a specific day can blur the line between normal emotional responses and clinically relevant conditions. In some cases, it may also reinforce a nocebo effect, encouraging people to interpret normal fluctuations in mood as signs of pathology.

For clinicians, this oversimplification can complicate patient encounters. Patients may present with concerns triggered by media exposure, asking whether they are “supposed” to feel depressed or whether their symptoms are abnormal. Addressing these concerns requires a careful balance: validating emotional distress without medicalizing normal experiences, while remaining vigilant for warning signs of true depressive disorders.

Clinical implications: what should physicians do?

Blue Monday itself does not warrant specific clinical action, but the period it highlights can serve as a useful reminder to pay attention to mental health. In everyday practice, clinicians across specialties should be aware of red flags such as persistent low mood lasting more than two weeks, loss of interest or pleasure, significant functional impairment, suicidal ideation, or marked changes in sleep and appetite.

Simple screening tools, such as brief depression questionnaires, can be helpful when symptoms raise concern. When Seasonal Affective Disorder (SAD) or major depression is suspected, evidence-based interventions should be prioritized according to established guidelines (Munir et al., 2024).

Among these, light therapy has proven to be a cornerstone of treatment. Meta-analyses (Golden et al., 2005; Chen et al., 2024) support the efficacy of daily exposure to bright white light - specifically 10.000 lux for 30 minutes in the early morning. This intervention, which targets circadian rhythm resynchronization, has efficacy comparable to pharmacological treatments in selected patient populations, often with a faster onset of action and a favorable safety profile.

References
  1. Rosenthal NE, Sack DA, Gillin JC, Lewy AJ, Goodwin FK, Davenport Y, Mueller PS, Newsome DA, Wehr TA. Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy. Arch Gen Psychiatry. 1984 Jan;41(1):72-80. doi: 10.1001/archpsyc.1984.01790120076010. PMID: 6581756.
  2. Melrose S. Seasonal Affective Disorder: An Overview of Assessment and Treatment Approaches. Depress Res Treat. 2015;2015:178564. doi: 10.1155/2015/178564. Epub 2015 Nov 25. PMID: 26688752; PMCID: PMC4673349.
  3. Galima SV, Vogel SR, Kowalski AW. Seasonal Affective Disorder: Common Questions and Answers. Am Fam Physician. 2020 Dec 1;102(11):668-672. PMID: 33252911.
  4. Munir S, Gunturu S, Abbas M. Seasonal Affective Disorder. [Updated 2024 Apr 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK568745/
  5. Øverland S, Woicik W, Sikora L, Whittaker K, Heli H, Skjelkvåle FS, Sivertsen B, Colman I. Seasonality and symptoms of depression: A systematic review of the literature. Epidemiol Psychiatr Sci. 2019 Apr 22;29:e31. doi: 10.1017/S2045796019000209. PMID: 31006406; PMCID: PMC8061295.
  6. Winthorst WH, Roest AM, Bos EH, Meesters Y, Penninx BWJH, Nolen WA, de Jonge P. Seasonal affective disorder and non-seasonal affective disorders: results from the NESDA study. BJPsych Open. 2017 Aug 30;3(4):196-203. doi: 10.1192/bjpo.bp.116.004960. PMID: 28904813; PMCID: PMC5572284.
  7. Kim K, Kim J, Jung S, Kim HW, Kim HS, Son E, Ko DS, Yoon S, Kim BS, Kim WK, Lim C, Kim K, Lee D, Kim YH. Global prevalence of seasonal affective disorder by latitude: A systematic review and meta-analysis. J Affect Disord. 2025 Dec 1;390:119807. doi: 10.1016/j.jad.2025.119807. Epub 2025 Jul 3. PMID: 40614973.
  8. Zhang H, Khan A, Chen Q, Larsson H, Rzhetsky A. Do psychiatric diseases follow annual cyclic seasonality? PLoS Biol. 2021 Jul 19;19(7):e3001347. doi: 10.1371/journal.pbio.3001347. PMID: 34280189; PMCID: PMC8345894.
  9. Golden RN, Gaynes BN, Ekstrom RD, Hamer RM, Jacobsen FM, Suppes T, Wisner KL, Nemeroff CB. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry. 2005 Apr;162(4):656-62. doi: 10.1176/appi.ajp.162.4.656. PMID: 15800134.
  10. Chen ZW, Zhang XF, Tu ZM. Treatment measures for seasonal affective disorder: A network meta-analysis. J Affect Disord. 2024 Apr 1;350:531-536. doi: 10.1016/j.jad.2024.01.028. Epub 2024 Jan 12. PMID: 38220102.