Insomnia

Periods of sleep disturbance due to acute stress or environmental change are common human experiences. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classification of insomnia disorder is differentiated from an acute occurrence of sleep disturbance, requiring the disorder to be a major health complaint, presenting with more than three months of persistent problems (more than three nights per week) in initiating or maintaining sleep, or early morning wakening. Furthermore, for this diagnosis to be met the sleep disturbance must: cause significant distress or impairment in social or occupational functioning; be exclusive of other disorders (e.g. other sleep or psychiatric disorders); and not be due to medications, drugs, alcoholism or a general medical condition. Insomnia may be secondary—that is, caused by: another medical condition; medicines, recreational drugs or alcohol consumption; or environmental factors such as altitude, jet lag, poor bedding, excess light or noise. Due to this a thorough assessment is required to establish particulars of the causation. It is estimated that 25% of chronic insomnia can be classified as ‘primary’, with approximately 75% due to other aforementioned causations. Interestingly, people who experience ‘transient’ insomnia (less than one month), usually from an environmental change, acute social stressors or the loss of a loved one, usually experience daytime sleepiness during this period. A person with chronic insomnia usually does not feel sleepy but instead may feel ‘hyperstimulated’, even after only four to six hours’ sleep