(Original post by nash_4_lyf)
This is my essay plan for the topic :
Causes of insomnia: secondary insomnia – insomnia is a symptom and there is another underlying medical, psychiatric or environmental cause.
Primary insomnia: occurs on its own with no known cause, for more than a month.
Risk factors influencing insomnia
Age and gender – older people are more likely to suffer from insomnia. In older people, increasing physical problems = arthritis or diabetes may disrupt sleep and lead to insomnia. Increased incidence of insomnia in women is due to age-related hormonal fluctuations – menopause.
Sleep apnoea or other parasomnias (snoring, sleepwalking, teeth grinding) have a major disruptive effect on sleep.
Personality may be a factor in insomnia. Insomniacs were more likely to internalise psychological disturbance rather than acting out problems or being aggressive. The researchers proposed that internalisation leads to higher levels of emotional arousal and increased likelihood of feeling anxious, and that this is a risk factor for insomnia.
Explanations for narcolepsy
REM – 1960s = view that it was linked to a malfunction in the system that regulates REM sleep. Also explained classic symptoms of narcolepsy = lack of muscle tone (cataplexy).
Hypocretin – link between the neurotransmitter Hypocretin and narcolepsy. Hypocretins play an important role in maintaining wakefulness. Evidence = narcoleptic dogs had a mutation in a gene on chromosome 12 (disputes the processing of Hypocretin).
Causes of insomnia
Recent research casts doubt on whether insomnia is just an effect. It may be the cause. A study of almost 15,000 Europeans found that insomnia more often preceded than followed cases of mood disorder. This means that in some cases it is important to treat insomnia regardless of whether it is a primary or secondary effect.
Risk factors influencing insomnia
Spielman and Glovinsky propose a distinction between predisposing, precipitating and perpetuating components. Predisposing factors include genetic vulnerability for insomnia. Evidence = twin studies, Watson et al. = 50% of the variance in the risk for insomnia could be attributed to genetic factors. Research also suggests that physiological factors may predispose a person to develop insomnia. E.G. = it’s been found that insomniacs are more likely to experience hyper arousal (would make it more difficult to get to sleep) both when awake and asleep. This explains why only some people develop insomnia in response to stress, jet lag etc. However predisposing factors = not enough to develop chronic insomnia. The diathesis-stress model = vulnerability alone is not enough for a disorder to develop; environmental stressors are needed to trigger the disorder to develop (stress or environmental change).
Perpetuating factors are important (factors which maintain insomnia when the original cause have disappeared or been treated).
Treatment of insomnia
Treatments include relaxation techniques and improving sleep hygiene. Phototherapy can be used for circadian disruption. Sedatives, anti anxiety drugs and melatonin can be used. More psychological techniques can also be used, including attribution theory, sleep restriction theory and reconditioning.
The REM hypothesis: Vogel observed REM sleep in a narcoleptic patient. Supported by neuron activity in the brainstem of narcoleptic dogs that showed that cataplexy is linked to the activation of cells that in normal animals are active only in REM sleep.
Hypocretins: Findings from narcoleptic dogs have been confirmed in human studies = they had lower levels of Hypocretin in their cerebrospinal fluid. Low levels of Hypocretins are unlikely to be due to inherited factors = human narcolepsy doesn’t run in families and is not concurrent in twins. The reduction of Hypocretin may be due to brain injury, infection, diet or stress or the result of an auto immune attack. This could explain the HLA link with narcolepsy because of the role of HLA in the immune response.
Chronic insomnia – it is unlikely to be explained by one single factor. This makes it difficult to conduct research because studies only find small effects.
Individual differences – insomnia affects individuals in different ways, therefore research can not be generalised.
I have to learn it though.