[Do we need polysomnography in insomnia?]

The elimination of insurance coverage for polysomnography (PSG) in insomnia raised the question about the diagnostic value of this sole objective assessment of sleep. The methodology of PSG is described including the significant criteria for evaluating the recuperative value of sleep. Comparing clinical symptomatology and PSG shows, that the dominating symptoms are neither consistent nor specific, that the subjective evaluation of sleep by the patient is uncertain, and that extreme deviations may occur, especially in sleep state misperception. In the field of differential diagnosis, overlapping of insomnia with other disturbances within and outside the range of sleep medicine is frequent. Special problems arise in chronic non-organic pain. It is clear from all these aspects that PSG is indispensable in insomnia.