Kaamos Timo Partonen MD, research professor, adjunct professor of psychiatry National Institute for Health and Welfare (THL) University of Helsinki

> 50 000 < 2 000 < 1

Helsinki on Tuesday 7 January 2014 At 8:30 <3 lx At 9:30 34–42 lx At 10:30 176–186 lx At 11:30 390–420 lx At 12:30 240–280 lx At 13:30 299–320 lx At 14:30 180–205 lx At 15:30 32–35 lx At 16:30 <5 lx Helsinki on Tuesday 7 January 2014

Intrinsic pacemakers generate the rhythms Master circadian clock gives the pace. CRY1,2 J Endocrinol 2007; 195: 187-98. Ann Neurol 2015; 78: 317-22.

Light and darkness provide time cues Human key pacemaker entrains to morning light exposure. CRY1,2 Curr Biol 2007; 17: R44-5.

Master clock tends to delay Delays are greater during the puberty and winter months. Human intrinsic day is 23 h 41 min to 24 h 35 min (on average 24 h 5 min for women, 24 h 11 min for men). Science 1999;284:2177-81. Proc Natl Acad Sci U S A 2011;108 Suppl 3:15602-8.

Seasons challenge the master clock Morning-active in winter, evening-active in summer. Cell 2007;129:207-19.

immediate effect → alertness scheduled effect → mood and sleep Nat Neurosci 2010; 13: 239-45.

Hum Neurobiol 1982; 1: 195-204. J Theor Biol 1982; 98: 369-92.

Timing is essential Light at night makes the delays greater. Curr Biol 2013; 23: 1554-8.

Behavioral trait tells about the master clock Health hazards are greater in “night owls”. Owls Larks Sleep deprivation, unhealthy diet, emotional eating, smoking, alcohol use, sedentary activity, screen time, etc. Insomnia, nightmares, depression, winter blues, hypertension, type 2 diabetes, bronchial asthma, spinal disease, backache, long menstrual bleeding, etc. Mortality. FINRISK studies 2007 and 2012. Former elite athlete cohort.

You may advance or delay your master clock Lancet 1997; 350: 1611-6.

Light therapy Bright light via the eyes is the first option. Indications Winter depression, winter blues. All depressive episodes? Contraindications Relative: eye diseases, mood swings. Adverse events Temporary: headache, eye irritation, nausea.

Winter depression: what is it Winter depression: what is it? Of the depressed, 1 out of 10 has winter depression. Of the those aged 30 years or more in Finland: Winter blues at large → 20% of women, 12% of men Severe winter blues → 2.5% Winter depression → 0.9%

Winter depression Symptoms are a mixture. Kaamos symptoms: - prolonged sleep 76% - weight gain 74% - carbohydrate craving 70% Depressive symptoms: - loss of energy 96% - sadness 96% - social withdrawal 92% - irritability 86% - self-harm 35%

Light via the eyes is the treatment of choice Bright light therapy has a dosage and a schedule. 1. intensity: 2 500–10 000 lx, start with 3 000 lx (Distance from the lamps!) 2. duration: 15–120 min, start with 30 min. B. Schedule 1. clock time: at 6–9 a.m. 2. regularity: each morning (at least 5 times a week), the winter (or periods of 1–2 weeks).

How to take the light Eyes open in a light therapy room, at home, or at work.

How to take the light Eyes open in a light therapy room, at home, or at work.

How to take the light Eyes open in a light therapy room, at home, or at work.