This site is intended for health professionals only

Shedding light on winter depression

John M Eagles
MB ChB MPhil FRCPsych
Consultant Psychiatrist
Royal Cornhill Hospital
Aberdeen

In temperate countries such as the UK, the most common type of seasonal affective disorder (SAD) is "winter depression".
The most striking feature of winter depression is the regular recurrence of symptoms in autumn or winter with remission in the spring. It is estimated to affect over 3% of the adult population in the UK. The symptomatology and epidemiology have been described in more detail elsewhere,(1,2) but the most characteristic features can be summarised as follows:

  • A depressed mood.
  • Fatigue with daytime sleepiness.
  • Hypersomnia.
  • Increased appetite (often with carbohydrate and chocolate craving).
  • Increased weight.
  • Most commonly occurs in women in their ­reproductive years.

Factors specific to primary care

Presentation
While winter depression is increasingly recognised, most sufferers probably do not know they have it. This was certainly the case in our study among patients we diagnosed with SAD, using fairly stringent criteria, who were waiting to see their GPs during the month of January in Aberdeen.(3) Few of these patients with winter depression had self-diagnosed, and only for a very small number had consideration of the diagnosis been recorded in the primary care records. Compared with controls over a five-year period, the 123 patients we identified with winter depression had significantly more consultations, many more prescriptions, increased numbers of tests and investigations, and  more hospital referrals. Depression was often identified and treated, but patients presented with, and were treated for, a wide variety of symptoms. Compared with controls, they had more cardiovascular, gastro-intestinal and gynaecological presentations and were treated more often with analgesics and antibiotics. In short, it seems that the presentation of winter depression may often have been a somatic one.

Treatment
Light therapy involves a bright light source, without an ultraviolet component, from a lightbox or visor. While its efficacy has been demonstrated in several trials, it is noteworthy that these trials have been conducted in specialist tertiary centres in North America, where self-diagnosed and knowledgeable patients may come to see the experts, expecting to be treated with bright light. Our own small study of 59 patients with winter depression identified in primary care did not find that bright white light was superior to dim red light;(4) both groups of patients got much better with treatment. While light therapy is still likely to be effective among patients in primary care settings, it is no magic bullet, and treatment requires pragmatism, subtlety and trial and error.

Recognition and management
The recognition and management of patients with ­winter depression will be described through three ­representative case studies.

Case 1 (mild)
A 20-year-old female student presents in early December with a four-week history of fatigue and slightly lowered mood. She has impaired motivation and concentration, which is resulting in difficulty studying for her pre-Christmas examinations. She is irritable, notably with her boyfriend. Her sleep is prolonged, with difficulty wakening and getting to morning lectures. She is eating more comfort food and has put on some weight. She has ceased taking regular exercise.
She identifies a similar pattern over the two preceding academic years with remission in spring. In the summer, she functions well and regards herself as a normal, outgoing, fun-loving student.
The diagnosis of mild winter depression is clear from the symptoms and their recurrent seasonal pattern. Discussion might first usefully focus upon the precipitating and maintaining interactive factors shown in Figure 1.

[[NIP02_fig1_128]]

The emphasis, certainly initially, would be on developing "self-help mastery" over these symptoms of winter depression, which fall around the border between normality and mild SAD.
Exposure to daylight and exercise (which can be combined by walking outside regularly) are cornerstones. It is often helpful to identify the shortest day (21 December) as a "psychological winning post", after which daylight hours lengthen and natural remission approaches. If this is ineffective, light therapy would be the next logical step.(2)

Case 2 (moderate to severe)
A lady in her 40s has had previous treatment for depression and attends in January with a three-month history. She is depressed and anergic, and feels too tired to go to work. She is eating voraciously and has gained over a stone in weight. She is spending a lot of time in bed, but says she is sleeping poorly with early-morning wakening around 6am. She reports that she has felt like this over the last several winters. Practice records show that she has taken antidepressants during winter, and also twice during the summer. She reports that a sunny winter holiday last year had an uplifting effect on her mood.
This woman has many typical features of winter depression, and while the "self-help mastery" approach is again relevant to her, she needs additional treatment. She is atypical of classical SAD with respect to her early-morning wakening and the occurrence of episodes during the summer months. In general terms, the more a patient has the classical features of winter depression (hypersomnia, carbohydrate craving, weight gain, low mood only in autumn and winter), the more one would tend to advise light therapy as the first choice of treatment. On the other hand, the more symptoms of non-seasonal depression prevail (early morning wakening, weight loss and summer depressions), the more readily one would prescribe antidepressants. For this woman, either treatment would be appropriate, adding the other if response is incomplete. Patient preference, past effectiveness of antidepressants, previous antidepressant side-effects and availability of light therapy may well determine which is tried first. Since hypersomnia and fatigue are usually prominent, non-sedative antidepressants are preferred. Selective serotonin-reuptake inhibitors (SSRIs) are the most appropriate first choice. Venlafaxine is often helpful, and there are reported successes with the specific noradrenergic reuptake inhibitor reboxetine. If tricyclics are to be used, less sedative preparations such as imipramine are preferred.

Case three (somatised)
A 35-year-old woman is a very frequent surgery attender. Her records indicate that she presents with a wide variety of different symptoms including premenstrual syndrome, urinary tract infections, head and back pain, fatigue and weight gain. Her presentations often remain medically unexplained. She has had many investigations and many prescriptions, notably for antibiotics and analgesics. She has also had antidepressants. While she is a frequent attender at surgeries across the months of the year, her attendances peak between October and April. On questioning, she acknowledges feeling low, lethargic and generally ill in winter, at which time she gains weight and oversleeps.
As with many somatised presentations, this woman might not readily accept that some of her morbidity may be attributable to depression, and for the same reason adherence to prescribed treatment may not be good.
On the other hand, the clear biological aetiology of winter depression (light deprivation) can make the diagnosis and treatment more acceptable.
Furthermore, if light therapy is used as a first-choice treatment, patients often find this attractive and, in terms of optimising placebo responses, few management strategies can be better than sitting for 30 minutes or more each morning in front of a bright light.
For somatised winter depression, self-help strategies are particularly important as they can help to move the patient to a model of ameliorating their own ailments rather than relying on the medical profession to do so. Any partial response to light therapy and/or self-help technique can be built upon by prescribing ­antidepressants.

[[NIP02_pp_128]]

References

  1. Lam RW. Seasonal affective disorder: diagnosis and management. Primary Care Psychiatry 1998;4:63-74.
  2. Eagles JM. Seasonal affective ­disorder. In: Royal College of General Practitioners Members' Reference Book, 2000/01. London: Campden Publishing; 2000. p. 337-40.
  3. Eagles JM, Wileman SM, Cameron IM, et al. Seasonal affective disorder among primary care attenders and a community sample in Aberdeen. Br J Psychiatry 1999;175:472-5.
  4. Wileman SM, Eagles JM, Andrew JE, et al. Light therapy for seasonal affective disorder in primary care: randomised controlled trial. Br J Psychiatry 2001;178:311-16.

Resource
SAD Association
PO Box 989
Steyning BN44 3HG
W:www.sada.org.uk

Further reading
Rosenthal NE. Winter blues. New York: Guilford Press; 1993.