Sleep is so important to our general well being and affects our ability to cope with day to day life, stress levels, immunity etc. therefore sleep deprivation or disturbed sleep can lead to all sorts of issues. Hypnosis, through supporting clients to better relaxation states, effectively improves the quality of sleep. Several studies were made to assess the effect of hypnosis in sleep. In one study, Swiss researchers monitored the brain activity of a group of healthy, young women as they took a 90-minute nap after listening to a hypnotic suggestion tape. They found that women who were deemed the most susceptible to hypnosis spent 80 per cent more time in slow-wave sleep (the deep, restorative phase of our shut-eye) after listening to the hypnosis tape than they did after listening to a neutral spoken text.