A lot of 2020 has been spent either staring at, or climbing up, the walls (depending on how lockdown has gone for you). We’ve all been hidden away for so much of the year that it’s easy to forget how closely connected we are to the world around us – how it can affect our physical and mental selves. A beautiful example is shinrin yoku (‘forest bathing’), the Japanese phrase for the deep relaxation you experience in the dappled green light and cool air of a forest. A less positive example is Seasonal Affective Disorder, also called ‘winter depression’ or ‘winter blues’.
DSM-IV, the taxonomy of psychiatric conditions, lists it as “a specifier of major depression” – in other words it’s not a mood disorder per se. Instead it’s a doorway that opens up for some people at certain times of the year, and leads them to depression: mild in some cases, much worse in others (about 1 in 16 people get it really badly). 27 is the average age of SAD onset, and it disproportionately affects younger women: 80% of sufferers are women, reducing to 50% in later years. (As an aside, I always wondered if Vashti Bunyan suffered from SAD. If she did, she managed to create something hauntingly lovely from it).
Even though it’s a “specifier”, it does have some atypical symptoms. Instead of decreased sleep and poor appetite, SAD can cause increased sleep, increased appetite (especially carbohydrate craving), weight gain (unsurprisingly), irritability, interpersonal difficulties (especially rejection sensitivity), and leaden paralysis (a heavy, leaden feeling in the arms or legs). It’s not a lot of fun.
As many of you will know, depression has no single cause. Possible factors can include “faulty mood regulation by the brain, genetic vulnerability, stressful life events, medications, and medical problems”, according to Harvard Medical School). Similarly, not a great deal is known about the biological processes driving SAD. The leading theory, says the NHS, is that reduced exposure to sunlight stops the Hypothalamus from working effectively. This increases production of melatonin (the hormone which makes you sleepy), affects your body clock (which tells you when to wake and sleep) and inhibits serotonin, which regulates mood, appetite and sleep and is closely linked to feelings of depression.
Ever wondered what ‘body clock’ actually means? Well we all have time-regulating molecule interactions throughout our bodies, but we also have a master clock: the Suprachiasmatic Nucleus (SCN), a group of cells in the Hypothalamus that is directly linked to our optic nerves. It responds to light and dark, and so regulates our Circadian rhythms. Also in the Hypothalamus (the Paraventricular Nucleus, since you asked) are corticotropin-releasing hormone (CRH)-containing cells which are triggered by serotonin and regulate the hypothalamic-pituitary-adrenal axis. This is important because, as Hanley et al at the University of Chicago revealed, “the intimate relationship between serotonin and the hypothalamic-pituitary-adrenal axis is of great importance in normal physiology such as circadian rhythm and stress, as well as pathophysiological disorders such as depression, anxiety, eating disorders, and chronic fatigue.”
This delicate biological system, like so many others, can easily be pushed out of whack – especially when SAD is shown to have such a specific effect on the Hypothalamus. We also know that CBD regulates Seratonin levels and so affects anxiety levels, and directly plugs into the body’s ECS: the signalling system that regulates so many of our natural processes, including the hypothalamic-pituitary-adrenal axis.
If you are susceptible to SAD, there are many ways to treat it: antidepressants, counselling, CBT, vitamin D and light therapy among them. As part of a holistic lifestyle, CBD can play a huge role in homeostasis – the natural balancing of the body’s finely tuned processes. Don’t forget, if you are taking medication for SAD, to speak to your doctor before taking CBD.
So as the nights get longer, please do take care of yourself and hopefully you can banish the winter blues.