Beat the winter blues: tackling seasonal affective disorder

Brace yourselves, winter is coming. Oh wait, it’s already here. For some this merely means warm jackets, ski tour (!) and an even better reason not to show up to a 9 a.m. lecture on a Monday morning (it was too cold to get out of bed – honest!). But for others, the shortening of the days brings about a change in mood and behaviour that is much more than just a case of the ‘winter blues’.

Seasonal affective disorder (SAD) is a subtype of major depression that occurs at the same time every year in people with otherwise normal mental health; it affects approximately 7% of the UK population. The majority of people with SAD have ‘winter depression’ i.e. they go through a depressive period in fall/winter but recover in spring/summer. The reverse is true for a small minority of people with ‘summer depression’.

The symptoms of winter-onset SAD are manifold. You feel depressed, hopeless and anxious. You lack energy, oversleep or have insomnia, lose interest in the activities you once enjoyed, and distance yourself from friends. It becomes even harder to concentrate in lectures, no matter how fascinating. To make matters worse, you experience changes in appetite that make you crave carbohydrate-packed foods (and in a crazed midnight binge you discover that Vialli’s delivers). So naturally you put on weight faster than a bear preparing for hibernation. Even your once rampant sex drive seems to have deflated. In severe cases, thoughts of death/suicide may cloud your mind, or you may turn to alcohol and/or drugs to escape reality.

Since these symptoms are common to many mental health disorders, such as clinical depression or bipolar disorder (or just first year university students), diagnosing SAD is not straightforward. To be diagnosed with SAD, you must have a) have a (family) history of major affective disorder, b) have experienced seasonal periods of depression followed by normal periods for the past two years at least (with no non-seasonal depression in-between), c) no other psychiatric disorders and d) no other stress factors that could explain these seasonal mood changes.

But what is causing this rollercoaster of emotions? Answer: nobody knows. But there are a number of good explanations. Significant evidence has been gathered that a deficiency in environmental light is a major factor causing SAD. Studies have shown that the severity of SAD symptoms increases as the days grow shorter.

Rosenthal and his colleagues, who first defined the disorder in 1984, also showed that moving to an equatorial latitude i.e. to where day-length remains constant, prevents SAD. Recent research has shown a connection between melanopsin photoreceptor cells – light-sensitive cells in your eye – and SAD; these cells are involved in mediating the effects of light on the body’s internal clock (circadian rhythms), melatonin secretion and alertness. Changes in environmental light therefore result in altered signaling from these photoreceptors, which in turn could affect these systems.

The ‘phase shift’ hypothesis, for instance, states that SAD is due to uncharacteristic delays in circadian rhythms caused by changes in day length. Abnormal secretion and sensitivity to melatonin – the hormone regulating the sleep-wake cycle – has also been implicated in causing SAD, though this has been disputed. Strong evidence, however, exists to suggest that disruptions in serotonin function – a neurotransmitter involved in mood, appetite and sleep regulation – leads to the development of SAD. This is because many SAD symptoms, such as the overeating, carb-cravings and oversleeping are related to decreases in serotonin.

Sadly the NHS doesn’t cover your move to the Maldives, no matter how severe your symptoms. Less extravagant treatments for SAD include light therapy, cognitive behavioral therapy (CBT) and/or antidepressants. Light therapy involves exposure to a dosage of 5,000 lux per day from a specialized light box and is most effective when administered in the morning. It counteracts the effects of decreasing environmental light in winter. CBT i.e. psychotherapy aims to improve a patient’s underlying thoughts and attitudes to combat depression.

Finally, certain antidepressants such as sertraline hydrochloride (Zoloft) or fluoxetine (Prozac) – which both work by inhibiting serotonin reuptake into neurons, thereby increasing the level of free serotonin available for signaling – have been shown to alleviate SAD symptoms. Of course, getting out of the house (to catch those last few rays of sun) and regular exercise are lifestyle adjustments you yourself can make to combat the apathy and depression associated with SAD.

Experiencing various symptoms named above at some point during winter is a common occurrence and not necessarily a sign of an underlying mental health problem (even if the internet is telling you that you definitely have bipolar disorder. And schizophrenia). However, if these feelings of depression don’t go away and even worsen, you should consult a doctor or mental health practitioner. Do not suffer in silence. Winter does not have to be a period of self-pity and –loathing, and getting help is not a sign of weakness. For more information on seasonal affective disorder, visit nhs.uk/conditions/Seasonal-affective-disorder.