Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light
ABSTRACT— “Midwinter insomnia” (MI), mainly characterized by difficulties in falling asleep at night, is a common complaint during the period of obscuration or “dark period” north of the arctic circle. We hypothesize that MI is a result of a phase delay of the sleep‐wake cycle due to insufficient ex...
Published in: | Acta Psychiatrica Scandinavica |
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1987
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crwiley:10.1111/j.1600-0447.1987.tb02811.x 2023-12-03T10:18:11+01:00 Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light Hansen, T. Bratlid, T. Lingjärde, O. Brenn, T. 1987 http://dx.doi.org/10.1111/j.1600-0447.1987.tb02811.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0447.1987.tb02811.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0447.1987.tb02811.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Acta Psychiatrica Scandinavica volume 75, issue 4, page 428-434 ISSN 0001-690X 1600-0447 Psychiatry and Mental health journal-article 1987 crwiley https://doi.org/10.1111/j.1600-0447.1987.tb02811.x 2023-11-09T13:19:34Z ABSTRACT— “Midwinter insomnia” (MI), mainly characterized by difficulties in falling asleep at night, is a common complaint during the period of obscuration or “dark period” north of the arctic circle. We hypothesize that MI is a result of a phase delay of the sleep‐wake cycle due to insufficient exposure to daylight. In the present study based on this hypothesis, we wanted to find out whether otherwise healthy subjects with MI show abnormalities in the endocrine markers melatonin and cortisol late in the the evening, and whether exposure to intensive light for one half hour in the morning for 5 days has any effect on the insomnia and on the endocrine variables. Nine subjects with typical MI were compared to eight controls. Before light exposure, the MI group had a significantly lower level of plasma melatonin in the evening than the controls, and a nonsignificant increase of plasma cortisol. After light exposure, the following results were seen in the MI group: sleep latency was moderately but significantly shortened, plasma melatonin increased to the same level as in the controls, and there was a nonsignificant increase of plasma cortisol. These results are largely in accordance with the predictions made from the phase delay hypothesis. However, other explanations cannot be ruled out. Article in Journal/Newspaper Arctic Subarctic Wiley Online Library (via Crossref) Arctic Midwinter ENVELOPE(139.931,139.931,-66.690,-66.690) Acta Psychiatrica Scandinavica 75 4 428 434 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Psychiatry and Mental health |
spellingShingle |
Psychiatry and Mental health Hansen, T. Bratlid, T. Lingjärde, O. Brenn, T. Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
topic_facet |
Psychiatry and Mental health |
description |
ABSTRACT— “Midwinter insomnia” (MI), mainly characterized by difficulties in falling asleep at night, is a common complaint during the period of obscuration or “dark period” north of the arctic circle. We hypothesize that MI is a result of a phase delay of the sleep‐wake cycle due to insufficient exposure to daylight. In the present study based on this hypothesis, we wanted to find out whether otherwise healthy subjects with MI show abnormalities in the endocrine markers melatonin and cortisol late in the the evening, and whether exposure to intensive light for one half hour in the morning for 5 days has any effect on the insomnia and on the endocrine variables. Nine subjects with typical MI were compared to eight controls. Before light exposure, the MI group had a significantly lower level of plasma melatonin in the evening than the controls, and a nonsignificant increase of plasma cortisol. After light exposure, the following results were seen in the MI group: sleep latency was moderately but significantly shortened, plasma melatonin increased to the same level as in the controls, and there was a nonsignificant increase of plasma cortisol. These results are largely in accordance with the predictions made from the phase delay hypothesis. However, other explanations cannot be ruled out. |
format |
Article in Journal/Newspaper |
author |
Hansen, T. Bratlid, T. Lingjärde, O. Brenn, T. |
author_facet |
Hansen, T. Bratlid, T. Lingjärde, O. Brenn, T. |
author_sort |
Hansen, T. |
title |
Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
title_short |
Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
title_full |
Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
title_fullStr |
Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
title_full_unstemmed |
Midwinter insomnia in the subarctic region: Evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
title_sort |
midwinter insomnia in the subarctic region: evening levels of serum melatonin and cortisol before and after treatment with bright artificial light |
publisher |
Wiley |
publishDate |
1987 |
url |
http://dx.doi.org/10.1111/j.1600-0447.1987.tb02811.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0447.1987.tb02811.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0447.1987.tb02811.x |
long_lat |
ENVELOPE(139.931,139.931,-66.690,-66.690) |
geographic |
Arctic Midwinter |
geographic_facet |
Arctic Midwinter |
genre |
Arctic Subarctic |
genre_facet |
Arctic Subarctic |
op_source |
Acta Psychiatrica Scandinavica volume 75, issue 4, page 428-434 ISSN 0001-690X 1600-0447 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1600-0447.1987.tb02811.x |
container_title |
Acta Psychiatrica Scandinavica |
container_volume |
75 |
container_issue |
4 |
container_start_page |
428 |
op_container_end_page |
434 |
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1784265172899069952 |