Acute insomnia lasts up to 3 months. It is often referred to as adjustment insomnia because it most often occurs in the context of an acute situational
Insomnia is defined as repeated difficulty with the initiation, duration, maintenance or quality of sleep that occurs despite adequate time and opportunity for sleep and results in some form of daytime impairment. Approximately one-third of adults report some difficulty in falling asleep and staying asleep during the past 12 months, with 17 per cent reporting this problem as a significant one. Insomnia is usually a transient or short-term condition. In some cases, however, insomnia can become chronic.
Acute insomnia lasts up to three months. It is often referred to as adjustment insomnia because it most often occurs in the context of an acute situational stress, such as a new job or an upcoming deadline or examination. The insomnia typically resolves when the stressor is no longer present or the individual adapts to the stressor. However, transient insomnia often recurs when new or similar stresses arise in the patient’s life.
Chronic insomnia lasting longer than one month can be associated with a wide variety of medical and psychiatric conditions and typically involves conditioned sleep difficulty, but it is believed to occur primarily in patients with an underlying predisposition to insomnia. The different subtypes of chronic insomnia are described in Etiology.
Despite inadequate sleep, many patients with insomnia do not complain of excessive daytime sleepiness, such as involuntary episodes of drowsiness in boring, monotonous, non-stimulating situations. However, they do complain of feeling tired and fatigued, with poor concentration. This may be related to a physiological state of hyper-arousal. In fact, despite not getting adequate sleep, patients with insomnia often have difficulty in falling asleep even for daytime naps.
Chronic insomnia also has numerous health consequences. For example, patients with insomnia demonstrate slower response to challenging reaction-time tasks. Moreover, patients with chronic insomnia report reduced quality of life, comparable to that experienced by patients with such conditions as diabetes, arthritis and heart disease. Quality of life improves with treatment but still does not reach the level seen in the general population.In addition, chronic insomnia is associated with impaired occupational and social performance and an elevated absenteeism rate that is 10-fold greater than controls. Furthermore, insomnia is associated with higher health care use, including a 2-fold increase in hospitalisations and office visits.
In fact, insomnia often persists despite treatment of the underlying medical or psychiatric condition, and, in certain cases, the persistence of insomnia can increase the risk of relapse of the primary condition. In this regard, the clinician needs to understand that insomnia is a condition in its own right that requires prompt recognition and treatment to prevent morbidity and improve quality of life for their patients.