Insomnia Flashcards
Hyper-arousal explanation
Insomniacs are more likely to experience hyperarousal (high physiological arousal) characterised by an increase in certain somatic symptoms i.e body temperature, heart rate and metabolic rate. The person suffering from hyperarousal is in constant state of fight or flight response. Many Insomniacs feel less sleepy during the day than NI, even though they may sleep less at night, and at night this continued higher arousal means that they have difficulty sleeping. Thus it is reasonable to speculate that primary insomnia is caused by a malfunction in our sophisticated sleep control system most likely of a biochemical nature. This may be genetic as there is evidence that primary insomnia runs in families.
Primary insomnia
Primary Insomnia is the inability to go to sleep or to remain asleep which occurs in the absence of any psychological, physical or environmental cause. Thus the insomnia is the persons primary problem.
Vgontzas et al: ^ ACTH & Cortisol
The theory of hyperarousal is supported by Vgonstaz who found that Insomniacs have increased levels of ACTH and cortisol, both of which are associated with stress and arousal. These findings appear to be consistent with the idea that people with insomnia are in a state of hyperarousal during sleep. It has even been suggested that hyperarousal is the key defining element of insomnia, rather than sleep loss and sleep deprivation.
Winkleman et al: reduced GABA
Further support for the hyperarousal explanation comes from Winkleman et al who found that people who had been suffering with insomnia for more than six months had reduced levels of the neurotransmitter GABA (a brain activity reducing NT). A reduction in GABA means that the brain is not being quietened down at night, this might account for the common complaint amongst insomniacs that they are sometimes unable to sleep because they can’t switch off their thoughts at night.
Watson et al: MZ 0.47/DZ 0.15
It is also argued there is a genetic vulnerability to insomnia as exemplified by Watson et al who studied 1870 twin pairs (MZ & DZ). They found that MZ twin insomnia was highly correlated, at 0.47. DZ insomnia on the other hand was poorly at 0.15. This suggests that whilst genes do not absolutely predict insomnia they have a strong influence on the disorder. Particularly due to the significant difference between the two correlations.
Bonneau et al: 35% first degree relative
Further to this Bonneau et al reported that 35% of Insomniacs surveyed had a first degree relative with a current or recent problem with insomnia. This indicates there is a strong foundation of support for a biological explanation for primary insomnia.
Bonneaua: behavioural insomnia
However Bonneau et al research brings to light an alternative explanation whereby insomnia is a learned response, conditioned via expose to insomniac family or stress. exp suggests periods of insomnia at times of extreme streets /anxiety. in some people the insomnia persists even in the absence of stress and anxiety. original stress goes, but bc of association sleep related anxiety leads to a persistent learned primary insomnia. This suggest that insomnia occurs due to a learned response rather than a biological predisposition.
Biological determinism
Much of this discussed research suggests that physiological factors i.e imbalanced biochemistry predispose a person to develop primary insomnia, thus suggesting insomnia is biologically determined. However it is argued that we can exercise free will over our sleeping pattern by exercising or by reducing our exposure to blue light which proves successful in alleviating insomnia.
Secondary insomnia
In secondary insomnia there is a single underlying medical, psychological or environmental cause. In such cases insomnia is a symptom of the main disorder i.e. It is secondary.
Symptom of illness explanation
2nd insomnia is a symptom of many illnesses such as depression or heart disease. It is also typical of people who have circadian rhythm disorder i.e phase delay syndrome. 2nd insomnia may also be the result of environmental factors such as too much caffeine (coffee, tea or chocolate) or alcohol. Another common cause of 2nd insomnia is sleep apnoea, the cessation of airflow during sleep, preventing air from entering the lungs. The pauses where a person stops breathing while asleep may last from a few seconds to minutes and may occur 5-30 times an hour. When people experience an episode of apnoea during sleep the brain automatically wakes the person up in order to breathe again. This consistent disruption manifests as secondary insomnia.
Katz et al: insomnia as a symptom of medical illness
There is empirical support for the suggestion that insomnia is a symptom of a medical illness. Katz et al conducted a study involving 3455 patients with a diagnosis of one or more of five chronic medical conditions. Self report measure showed that 50% of them reported symptoms indicative of insomnia. The insomnia was rated mild in 34% of the patients and severe in 16%. The findings also suggested that insomnia had a significant negative effect on the QOL of the patients, beyond the effects of their other illnesses. This supports the theory that insomnia is a secondary symptom associated with physical and psychological illness.
Mercer et al: self report measures lack objectivity
However it is argued that self report measure lack objectivity as Insomniacs tend to over estimate their sleep problems. This is exemplified by Mercer et al who found that some individuals greatly overestimate the time it takes to fall asleep and underestimate how long they have slept for, when in fact EEG scans show they sleep more than reported. Resultantly self report measures should not be overly relied on as they challenge the reliability and validity of the research and undermine the theory that insomnia is caused by other illnesses.
Kamerow: problems with differential diagnosis
There is also the problem of differential diagnosis of insomnia, as its is a well known secondary symptom of many mental health disorders i.e depression. Kamerow states that insomnia is 10x more likely to be a result of a mental health problem than it is a physical one. And as the tradition in psychiatry is to treat the underlying condition it becomes difficult to do so when insomnia is co-morbid with the majority of psychological conditions as we cannot establish which causes the other.
