• 'Blue Monday' supposedly marks the date that people feel their lowest

  • Therapist Larissa Walker debunks this marketing myth and explores how Seasonal Affective Disorder works

  • If you are struggling this winter, we have therapists and counsellors available here 

Sudden ‘Blue Monday’ blues? This is very unlikely, and here is why. Blue Monday is a date of purely commercial nature, invented to encourage holidays sales by a now defunct holiday company and TV channel Sky Travel. Its existence has not been scientifically proven. A large study conducted in the Netherlands even concluded that there was no difference in peoples' moods from season to season, which makes a sudden deep low of one January Monday even more unlikely. Other research showed that the seasonal component may lead to existing depression or other mental health conditions worsening.

General winter blues, however, is not a myth. It is a condition called Seasonal Affective Disorder or SAD – a form of depression that can be quite overwhelming for some people. It is not very widespread and affects around 5-10% of the population. SAD is more common in the Northern Hemisphere where the body clock is disrupted by the lack of daylight in winter. It is also more prominent in women and young adults.

SAD is caused by a lack of sunlight, which leads to a lower level of serotonin (a hormone responsible for mood and appetite), a higher level of melatonin (a hormone that promotes sleep), and a lower level of vitamin D which some studies found to be correlated with depression.

SAD is not a standalone diagnosis and is missing from some standard diagnostic manuals used around the world. One of them – ICD-10 – only mentions ‘seasonal depression'. SAD symptoms are:

  • Fatigue
  • Difficulty concentrating
  • Lack of interest in various activities and feeling hopeless
  • Irritability
  • Lethargy and general tiredness
  • Lower libido
  • Feeling low and unhappy
  • Weight gain
  • Hypersomnia (sleeping too much)
  • Carbohydrates craving

As much as I like scientific evidence, I also prefer to find practical solutions that can make one’s life a bit easier right now, in addition to any medium and long-term therapeutic work. So, the questions I will explore here are: am I experiencing SAD, and what can I do about it?

Is it SAD?

Long symptom lists are a great starting point, but it is even more important to establish how many of those you are experiencing, whether they are recent or not, and how much they are affecting your quality of life.

Is it recent?

If you are feeling down for a couple of weeks and tick most (but not all) the boxes – you might be experiencing SAD. Or, if you have been diagnosed with depression before and feel worse during the winter months, SAD is likely making your depression worse. Some studies suggested that SAD is a component of major depression, not a type of depression on its own. 

A longer history of feeling low, from the time before January, might indicate that you are experiencing general depression. In that case, whether there is or is not a SAD element to it might not be that important. What’s important is to address the underlying feelings.

How bad is it?

You should be on a particularly high alert if your life is noticeably affected: you can’t perform your daily tasks, your sleeping and appetite are poor, or your work, relationships, and social life are affected. This is dangerous because it may lead to an accelerating negative impact on your physical health, making your depression worse at the same time. In this case, it’s advisable to talk to your GP. And if you are having dark suicidal thoughts – call your GP or 111 right away.

I’m not affected too badly. What can I do?

If your symptoms do not affect your quality of life, there are a few things you can do yourself to manage them. First, ask yourself what’s changed in your life and routine recently. Have you been less active and didn’t go out of the house as much? Cold weather might have made you reluctant to go out and exercise. Staying at home and not having much exposure to daylight may enhance seasonal depression.

Have you been continuing some Christmas holiday habits such as indulging in food and - particularly - drink? Alcohol is a strong ‘depressant’ and can make you feel both anxious and depressed, as well as disrupt sleeping patterns. Poor sleep combined with alcohol indulgence may lead to an even lower mood.

Have you seen less of friends and family? Lack of connection with others may also enhance low mood.

Now that you’ve done this quick assessment, explore what you can do about what you’ve discovered. If you haven’t been out much – make it a habit to get out for half an hour while it’s still bright outside. If you haven’t been talking to others like before – try to reconnect. If you have been overindulging in drinks – cut on alcohol by cutting its amount and frequency. But don’t make too drastic changes – the most comfortable (and feasible) process of change happens in little steps and starts with heightened awareness.

Finally, there are a few other well-known general ways of tackling SAD. One is a light therapy using a light box emitting 10,000 lux of light, for 20-30 minutes a day. There is also a less costly alternative – a daylight bulb that emits a full spectrum of light. You can buy it in a supermarket and sit under it for 45 minutes daily. Ideally, start light therapy before dark months as a preventative measure.

Another useful remedy is vitamin D that is found to be low in those with depression. The causal relationship is not clear but mental health specialists increasingly recommend it in conjunction with other methods of treating depression. It's worth asking your GP to test your vitamin D and explore the potential benefits of taking supplements.

In summary, like in any therapy, try to understand what is going on for you, how you are impacted, and experiment with making small changes when you are ready to do so.

Larissa Walker is a verified welldoing.org integrative psychotherapist in North West London and online

Further reading

How to manage feeling sad

6 common coping strategies that often make things worse

Breathing techniques for depression

5 things that helped me cope with depression

Why being outside is so good for mental health


Partonen, T. et al. (1996) ‘Effects of bright light on sleepiness, melatonin, and 25-hydroxyvitamin D₃ in winter seasonal affective disorder’, Biological Psychiatry, 39(10), pp. 865–872. doi: 10.1016/0006-3223(95)00294-4.

Parrish, E. (2018) ‘Winter blues, spring fever and major depression: Are they the same or different’, Perspectives in Psychiatric Care, 54(1), p. 5. doi: 10.1111/ppc.12256