Insomnia is classed as a sleep disorder which can be separated into: Primary insomnia which shows no obvious of psychological cause, secondary insomnia resulting of existence of psychological or physical problems. Insomnia can be categorised by sleepiness, fatigue, drop in alertness, difficulty concentrating, depression, and an over emotional state.

The ideas surrounding the, suggesting fact that personality contributed to being a core factor to influence insomnia was studies by Kales et al (1976). They found that 85% of insomniacs had abnormal personality’s categorised by psychasthenia, elevated levels of depression and conversion hysteria. Sufferers tended to internalise psychological disturbances, producing constant emotional arousal, suggesting that a psychophysiological mechanism underpins insomnia. However, Kales et al (1976) study fails to establish whether one factor causes the other, such as the possibility that personality causes insomnia and Vis versa. Significantly, this means that we cannot conclude that Personality has a direct influence on Insomnia. However, although there isn’t an established relationship between insomnia and personality, the study has provided practical applications. As nowadays, personality profiling is stressed more this is beneficial as personality types will be able to identify those who are possibly at risk of suffering from insomnia. This will allow people to get diagnosed earlier thus allowing possible treatment at an earlier stage of insomnia therefore minimising the future consequences of the disorder. Furthermore, the Study fails to take into account environmental factors such as the frequency of stressors encountered by patients on a daily basis. Surely, stressors such as work load, children, and education have an influencing factor of some of the symptoms of insomnia. This suggests that insomnia can be affected by the other factors such as the role of the environment on patients’ lives.

Furthermore, Terzano et al (1990) investigated the effect noise has on the ultradian rhythms in sleep. The study used six healthy volunteers they made five recordings of sleep under different noise conditions of increasing noise levels which was measured in dBA. This was attained by playing white noise (all different frequencies like the buzz of an out-of-tune TV) 45, 55, 65 and 75dBA as well as a bassline control. With increasing volumes they found changes in several aspects of sleep such as the fact that participants spent more time awake after falling asleep the first time, as well as more stage 2 and nREM sleep. Additionally the study found that participants were experiencing less stage 4 and REM sleep also less total sleep. Although noise is clearly associated with poor quality of sleep, part of the problem is caused by the way the sleep feels towards the noise. For example, if the noise is associated with annoyance they are more likely to have lower quality of sleep. This suggests that noise itself isn’t a core isolated factor in causing insomnia, but can influence sleep depending on how people associate certain noises. Furthermore, the study produces strong scientific evidence suggesting that noise has a significant impact on quality of sleep which has the possibility of causing sleeping disorders such as insomnia. The biological method of measuring sleep waves using electrodes to measure frequency of sleep waves provides objective and empirical data. This has resulted in more reliable data suggesting that there is a possible relation between noise and sleep.

Furthermore, Brezinova (1974) compared the effects of pre-sleep decaffeinated coffee compared with decaf with added caffeine. Even though the participants were unaware which coffee they received, those drinking coffee with caffeine experienced, on average, two hours less total sleep, took 66 minutes longer to fall asleep and their sleep was more broken. However, these results may have possibly been influenced by the fact that sleep being monitored may have nervous effects on participants’ sleep not the caffeine. This suggests that nerve may possibly have a greater effect than the caffeine on sleep, thus reducing the study’s validity. Although this, the study provides practical applications as the study suggests that if people are wanting to obtain an early nights’ sleep, they should not drink coffee including caffeine as it will delay sleep.