Night noise guidelines for Europe - WHO/Europe - World Health ...

EFFECTS ON HEALTH
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4.8.12 INSOMNIA AS A MENTAL HEALTH SYMPTOM
Insomnia is a symptom of many psychiatric disorders, especially depression and
anxiety. In studies of depressed patients compared to control subjects, there was
prolonged latency to sleep, increased wakefulness during sleep, early morning
wakening, decreased sleep efficiency and reduced total sleep time. There is also
evidence that insomnia may be a risk factor for developing depression (Riemann,
Berger and Voderholzer, 2001; Roberts, Roberts and Chen, 2002). This raises
the question as to whether prolonged noise exposure leading to insomnia provokes
the onset of depression in susceptible people? This seems theoretically
possible, but there is little evidence to support it. In a longitudinal study of adolescents,
it was the other way round – that depressive symptoms preceded the
onset of insomnia (Patton et al, 2000). Delayed sleep latency in children has
been linked to increased externalizing symptoms including aggressive behaviour,
and impaired attention and social problems (Aronen et al., 2000). In this crosssectional
study, the direction of association was uncertain, but it seems most
plausible that the sleep disturbance is a feature of the behavioural disturbance
rather than a cause of it. Three criteria have been suggested for sleep disturbance
to be environmentally determined: (1) the sleep problem is temporally associated
with the introduction of a physically measurable stimulus or definable set of
environmental circumstances; (2) the physical rather than the psychological
properties of the environmental factors are the critical causative elements; and
(3) removal of the responsible factors results in an immediate or gradual return
to normal sleep and wakefulness (Kraenz et al., 2004). Most studies do not fulfil
these criteria. In a German school-based study of 5–6-year-old children, sleep
disturbance by noise, largely from road traffic, was reported “sometimes” in
10% by parents of children and 2% “often”. Children’s reports were slightly
higher: “sometimes” in 12% and 3% “often” (Kraenz et al., 2004). Further longitudinal
research is needed to ascertain whether noise-induced insomnia leads
on to overt psychiatric disorder.
In summary, population as well as clinic-based studies have demonstrated a high
rate of psychiatric morbidities in patients with chronic insomnia. It has traditionally
been assumed that insomnia is secondary to the psychiatric disorders;
however, it is possible that in some cases the insomnia preceded the psychiatric
disorder.
4.8.13 DEPRESSIVE EPISODE AND ANXIETY DISORDERS
A mild depressive episode is diagnosed by clinical interview. The criteria for a
mild depressive episode include two or more symptoms of depressed mood, loss
of interest or fatigue lasting at least two weeks, with two or three symptoms such
as reduced concentration, reduced self-esteem, ideas of guilt, pessimism about the
future, suicidal ideas or acts, disturbed sleep, diminished appetite and social
impairment, and fewer than four symptoms including lack of normal pleasure/interest,
loss of normal emotional reactivity, waking =>2 hours early, loss of
libido, diurnal variation in mood, diminished appetite, loss of =>5% body
weight, psychomotor agitation or psychomotor retardation.
Anxiety disorders are similarly diagnosed by clinical interview. The criteria for
“generalized anxiety disorders” include duration of at least six months of freefloating
anxiety and autonomic overactivity.
NIGHT NOISE GUIDELINES FOR EUROPE