Every year, on the third Monday of January, the term Blue Monday reappears in the media and on social networks, often described as “the most depressing day of the year”. After the festive period, with colder weather, shorter days and a return to daily routines, many people can relate to feeling low during this time of year.
However, when we talk about mental health, it is important to separate scientific evidence from popular myths, and to approach wellbeing in a thoughtful and responsible way.
The concept of Blue Monday was first introduced in 2005 as part of a marketing campaign. It was based on a so-called formula that claimed to calculate the most depressing day of the year using factors such as weather, debt, motivation and time since Christmas.
Crucially, this formula has no scientific basis. It has never been peer-reviewed, published in a reputable scientific journal, or validated by independent research. Mental health organisations and researchers have repeatedly confirmed that there is no evidence to support the idea of a single day being the “most depressing” for everyone.
While Blue Monday itself is not supported by science, research does show that seasonal factors can influence mood and wellbeing for some people.
Reduced exposure to natural daylight during winter can affect circadian rhythms and the regulation of hormones such as serotonin and melatonin, which play an important role in mood, sleep and energy levels.
Some individuals experience Seasonal Affective Disorder (SAD), a clinically recognised form of depression linked to seasonal changes, particularly during autumn and winter.
Other winter-related pressures, such as financial concerns, social isolation, physical illness, or disrupted routines, may also contribute to feeling low or fatigued.
Importantly, these experiences do not affect everyone in the same way, and they do not peak on one specific day. Mental health is shaped by a complex interaction of biological, psychological and social factors over time.
Describing Blue Monday as “the most depressing day of the year” can unintentionally oversimplify or trivialise mental health difficulties, particularly conditions such as clinical depression or anxiety, which are serious, ongoing health issues that require understanding, compassion and appropriate support.
At the same time, it is completely valid to acknowledge that winter can feel challenging. Feeling low, tired or less motivated at times does not mean something is “wrong”, nor does it always indicate a mental health condition. Emotional wellbeing naturally fluctuates.
Using accurate, evidence-based language helps reduce stigma and encourages people to seek support when they need it, not just on one day of the year, but whenever difficulties arise.
Rather than focusing on a single date, it is far more helpful to think about ongoing ways to support mental health, especially during the winter months:
Maintaining regular sleep and daily routines
Staying physically active, even gently
Spending time outdoors and in daylight where possible
Staying connected with others and seeking support when needed
At Sisters Hospitallers, we believe in caring for the whole person (with dignity, compassion and respect) and in promoting mental wellbeing as an essential part of overall health, every day of the year.
If you or someone you care about is struggling with their mental health, reaching out for professional support is a positive and important step.