• M M Ohayon and P Lemoine.
• Stanford Sleep Epidemiology Research Center, School of Medicine, Stanford University, Stanford, California 94303, USA. mohayon@stanford.edu
• Encephale. 2004 May 1;30(3):222-7.

AbstractInsomnia is a frequent symptom in the general population; numerous studies have proven this. In the past years, classifications have gradually given more emphasis to daytime repercussions of insomnia and to their consequences on social and cognitive functioning. They are now integrated in the definition of insomnia and are used to quantify its severity. If the daytime consequences of insomnia are well known at the clinical level, there are few epidemiological data on this matter. The aim of this study was to assess the daytime repercussions of insomnia complaints in the general population of France. A representative sample (n=5,622) aged 15 or older was surveyed by telephone with the help of the sleep-EVAL expert system, a computer program specially designed to evaluate sleep disorders and to manage epidemiological investigations. Interviews have been completed for 80.8% of the solicited subjects (n=5,622). The variables considered comprised insomnia and its daytime repercussions on cognitive functioning, affective tone, daytime sleepiness and diurnal fatigue. Insomnia was found in 18.6% of the sample. The prevalence was higher in women (22.4%) than in men (14.5%, p<0.001) with a relative risk of 1.7 (95% confidence interval 1.5 to 2) and was twice more frequent for subjects 65 years of age or older compared to subjects younger than 45 years. Approximately 30% of subjects reporting insomnia had difficulties initiating sleep. Nearly 75% of insomnia complainers reported having a disrupted sleep or waking up too early in the morning and about 40% said they had a non-restorative sleep. Repercussions on daytime functioning were reported by most insomnia subjects (67%). Repercussions on cognitive functioning changed according age, number of insomnia symptoms and the use of a psychotropic medication. A decreased efficiency was more likely to be reported by subjects between 15 and 44 years of age (OR: 2.9), those using a psychotropic (OR: 1.5), those reporting at least three insomnia symptoms (OR: 1.4) and women (OR: 1.4). The highest probability of the appearance of concentration difficulties was found in subjects younger than 65 Years, having a depressive disorder and using a psychotropic (15-44 years: OR 19.1; 45-64 years: OR 46.6). Difficulties maintaining attention were 15 times higher in subjects aged between 45 and 64 who were using a psychotropic and had also a depressive disorder. Memory difficulties were three times more likely to be reported by subjects using a psychotropic. At the affective level, irritability was 10 times more likely to be reported by subjects younger than 65 Years who were also using a psychotropic and had a depressive disorder. Independent of the presence of a mental disorder and the use of a psychotropic, subjects between 15 and 44 Years were five times more likely to be irritable following a bad sleep. Feeling depressed after a bad night's sleep was 18 times more likely to occur in subjects aged between 45 and 64 who were using a psychotropic and had a depressive disorder. Feeling anxious after a bad night's sleep was seven times more likely to occur in subjects with a depressive disorder. Daytime sleepiness was reported by approximately 20% of insomnia subjects. This rate was relatively comparable among gender, age groups, presence/absence of a mental disorder and use or not of a psychotropic. However, taking into account the interaction between age, use of a psychotropic and the presence of a mental disorder, subjects younger than 65 years, using a psychotropic and having a depressive disorder were at least 10 times more likely to report daytime sleepiness. Subjects who were suffering the most diurnal symptoms of insomnia were those younger than 65 years. Several factors can be evoked to explain this fact. These subjects were, for the most part, likelier to have a stricter sleep/wake schedule because of constraints imposed by work, studies, child care, etc. Subjects older than 65 Years were generally retired and therefore less prone to sleepiness and to cognitive difficulties. Insomnia consequences were limited due to their inactivity. Complementary studies should be undertaken to describe the daytime repercussions of insomnia for this specific age group of the general population and to measure these repercussions.

17 keywords...

hide…