1. PRIMARY INSOMNIA

2. Theory -predisposing, precipitating and perpetuating factors explain primary insomnia -Predisposing factors = genetic vulnerability to insomnia and the physiological state of hyperarousal. -Hyperarousal = high physiological arousal when awake or asleep, makes it more difficult to fall asleep -Precipitating factors = stress or environmental change, such as changing time zones. Females and older people suffer more from primary insomnia, these facts count as precipitating factors -Perpetuating factors = maintain insomnia when the precipitating factors are gone. E.g. being tense before sleep or the expectation of poor sleep. KEY TO CHRONIC PRIMARY INSOMNIA

3. Research. Nofzinger et al (2004) found that the transition from being awake to being asleep is usually associated with a decrease in activity in the brain stem, thalamus and prefrontal cortex. Using pet scans, Nolfzinger et al showed that insomniacs experienced a smaller decline in such activity when going to sleep. In fact, they found elevated level of activity in the brains of insomniacs. This suggests that people who suffer from insomnia do so due to high Psychological arousal which supports the biological element of the explanation for insomnia

4. Bastien et al. (2004) found that 60% of patients with insomnia could identify a trigger for their sleep disturbance, and these tended to be around family, work/school and health. This study supports the idea that precipitating factors have an effect on insomnia because the stress of external factors such family problems (divorce) may have and effect on their health resulting in them not being able to sleep

5. Ohayon and Roth (2003) interviewed 14195 participants representative of the population of the UK, Italy Portugal and Germany over the phone about their psychiatric history and their sleep patterns. They found that people with insomnia were six times more likely to report a mental health issue, such as depression or anxiety than people without insomnia. This suggests that there are also psychological factors that can be linked to suffering from insomnia.

6. IDA – nature/nurture Predisposing part of the theory emphasises nature, while the precipitating part focuses on nurture (environmental factors). An advantage of looking at both is the practical applications that arise; biological factors can be treated in a scientific and experimental way, which makes it likely that treatments for insomnia can be developed. Additionally, if we know which environmental factors lead to a likelihood of insomnia, we can inform sufferers.

7. Wider Evaluation -Has led to the use of new treatments, such as drugs or CBT which targets the psychological causes of insomnia -Holistic explanation, states that there can be multiple explanations for insomnia. However, this can make it hard to study each factor seperately.