Sleep efficiency is defined as the percentage of time in bed spent asleep. Stage one sleep duration is significantly increased, resulting in the subjective experience of not sleeping. The increase in stage one sleep is frequently found alongside a decrease in delta sleep resulting in additional complaints of sleeplessness. There may also be increased electromyographic activity and increased alpha activity in the electroencephalograph. Finally, psychophysiological insomnia may coexist with other sleep disorders.
Psychophysiological insomnia can be a very distressing disorder.
It is considered a chronic condition when its duration is in excess of six months, sub acute when its duration is more than four weeks and less than six months, and acute when its duration is less than four weeks. The disorder usually begins during a period of acute stress in young adulthood and gradually worsens until the insomniac seeks treatment during middle adulthood. People suffering from insomnia usually describe themselves as light sleepers. Although a predisposition toward light sleep may have a genetic component it appears that the over concern with sleep and health behaviours is more strongly influenced by learned behaviours emphasized in some families. Females report more insomnia than males.