Insomnia risk factors

Disturbances of sleep are typical of mood disorders, and belong to the core symptoms of major depression. More than 90% of depressed patients complain of impaired sleep quality [60], Typically, patients suffer from difficulties in falling asleep, frequent nocturnal awakenings, and early morning awakening. Not only is insomnia a typical symptom of depression but, studies suggest, conversely, insomnia may be an independent risk factor for depression. In bipolar disorders sleep loss may also be a risk factor for the development of mania. Hypersomnia is less typical for depression [61] and, in contrast to insomnia, may be related to certain subtypes of depression, such as seasonal affective disorder (SAD). 

Assessing the effectiveness of a new drug candidate can be complex and often difficult. This is because some diseases or symptoms do not follow a predictable path. For example, acute conditions such as influenza or insomnia may resolve without intervention, while chronic conditions such as multiple sclerosis or arthritis follow a varying course of progression. Depending on age, treatment, and other risk factors, heart attacks and strokes may produce variable mortality rates. Additional difficulty is introduced by subjective evaluation, which can be influenced by the expectations of patients and physicians. Some of these issues can be addressed in controlled clinical trials. 

In this discussion, we will present a reanalysis of the CPSII data, to further explore the influence of comorbid risk factors on the mortality associated with sleep duration. The risks associated with insomnia, shift work, and sleeping pills will also be examined. 

Taylor DJ, Lichstein KL, Durrence HH (2003) Insomnia as a health risk factor. Behav Sleep Med 1 227-247... 

Klink M, Quan S, Kaltenborn W, Lobowitz M (1992) Risk factors associated with complaints of insomnia in a general adult population. Arch Intern Med 152 1634-1637... 

Some of the most common risk factors for development of insomnia are as follows ... 

Neckelmann, D., Mykletun, A., and Dahl, A.A., Chronic insomnia as a risk factor for developing anxiety and depression. Sleep, 30, pp. 873-880,2007. 

Abrupt alcohol withdrawal leads to a characteristic syndrome of motor agitation, anxiety, insomnia, and reduction of seizure threshold. The severity of the syndrome is usually proportionate to the degree and duration of alcohol abuse. However, this can be greatly modified by the use of other sedatives as well as by associated factors (eg, diabetes, injury). In its mildest form, the alcohol withdrawal syndrome of tremor, anxiety, and insomnia occurs 6-8 hours after alcohol consumption is stopped (Figure 23-2). These effects usually abate in 1-2 days. In some patients, more severe withdrawal reactions occur, with patients at risk of hallucinations or generalized seizures during the first 1-3 days of withdrawal. Alcohol withdrawal is one of the most common causes of seizures in adults. Several days later, individuals can develop the syndrome of delirium tremens, which is characterized by total disorientation, hallucinations, and marked abnormalities of vital signs. 

In CPSII, in the 32-covariate models, reported insomnia was associated with risk ratios slightly but significantly less than 1.0, after controlling for sleep duration (3). A similar result was found in another study (52). This might imply a protective effect of insomnia. Similarly, insomnia did not predict total mortality when depression and other comorbidities were controlled in major Swedish studies (13,53). In general, studies that control well for comorbid factors do not find that insomnia predicts increased mortality independent of sleep duration and hypnotic drug use. 

Indeed, in a survey of Japanese white-collar male daytime workers, psychological job stress factors, job satisfaction, and social support were independently associated with a modestly increased risk of insomnia [41], Furthermore, in a population of employees with no reported sleeping problems, 14.3 % developed a sleeping problem during the following year. Stress in the form of a poor psychosocial work environment doubled the risk of developing a sleep problem [42],... 

Insomnia is characterized as being primary where there is no obvious medical or psychiatric cause. It is a common clinical problan wherein 10-20% of people have chronic insomnia, characterized by trouble sleeping more than three nights a week. It has been directly linked to numerous impacts on individuals such as daytime fatigue, inattention, irritability, poor mood, and reduced energy levels. Consequently, they have reduced productivity, higher woik absenteeism, and an increased risk of depression or substance abuse. There is also a greater risk of traffic and woik-related accidents. Furthermore, studies have shown direct links between circadian rhythm disturbance and an increased risk in health problems, such as diabetes, metabolic disorders and depression. Insomnia is considered secondary if it is caused by external factors such as health conditions, for example, cancer, heart problems, depression, asthma, arthritis, or pain, or as a side effect of medication, or a substance, such as alcohol. 

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