This can create a vicious circle where worry leads to insomnia, which creates more worry about the effects of sleeplessness, which leads to more sleep disturbance. Secondary insomnia refers to sleep problems that are a symptom of an underlying medical or psychiatric condition. Physical health problems which result in pain such as angina, rheumatic disorders or gastric ulcers may lead to insomnia. Psychological problems such as anxiety disorders, scfhizophrenia and por-traumatic stress disorder may lead to sleep onset insomnia or waking as a result of vivid, frightening dreams. Terminal insomnia appears more commonly in those aged over 50.
Early morning waking is a particularly common feature in depression.
A wide range of drugs have an impact on sleep including steroids and medication for respiratory problems and high blood pressure. Alcohol and caffeine have long been known to have a negative effect on sleep. Unfortunately some medicines prescribed to combat insomnia can actually lead to insomnia or cause day-time drowsiness. Stressful life events such as divorce, death of a spouse or impending surgery can often trigger sleep disturbances which may persist beyond adjustment to the event itself. In addition, our own habits and behaviour patterns may contribute to insomnia.