The impact of adolescent sleep disorders upon neurocognitive function and the development of chronic pain conditions.

Childhood and adolescence is a critical period for developing homeostatic sleep-wake patterns. There is a growing body of evidence to suggest that childhood sleep problems may precipitate difficulties in later life. For example, sleep restriction in children can result in memory and verbal function deficits (Randazzo et al, 1998). Objective actigraphy monitoring also indicates that children (between ages 9 and 12) with higher levels of sleep fragmentation show diminished neurocognitive function on tests such as the continuous performance test and symbol digit substitution (Sadeh, Gruber and Raviv, 2002). Furthermore, Gregory et al (2009) found that sleep problems at ages 5 and 9 could predict neuropsychological deficits at age 13; specifically, tasks requiring a high demand of mental flexibility and working memory. Similar deficits in attentional capacity, memory and cognitive function have also been found in children with sleep-related breathing disorders (Blunden, Lushington and Kennedy, 2001; Beebe, 2006; Lewin et al, 2002). Overall, these studies highlight the importance of managing sleep disorders in childhood.

Pain is an interruptive but adaptive stimulus alerting us to potential threat or danger. Chronic pain patients, however, find it difficult to disengage from the constant threat of pain. Therefore, it is common for pain-related cognitive biases to develop as patients become increasingly vigilant to pain stimuli. Such maladaptive attention processes can unfortunately, prolong pain states. Neuropsychological complaints are common amongst chronic pain patients (Hart et al, 2001) and are assumed to stem from the attention-demanding interference of pain. It may be that pre-existing neuropsychological impairments can precipitate the transition from acute to chronic pain disorders however. If childhood sleep disorders can result in diminished neurocognitive capacity, this may induce a cognitive vulnerability wherein attention towards pain will already be enhanced due to problems with distraction and inhibition.

Psychosocial measures such as depression and negative beliefs about pain have been shown to increase one's probability of transitioning from an acute to a chronic pain condition (Casey, Greenburg et al, 2008; Pincus, Burton, Vogel and Field, 2002). Whether neuropsychological factors pose a risk for the development of chronic pain has yet to be addressed. If such risk factors are identified, early psychological interventions could be critical in preventing the development of certain pain conditions.

Aim and Objectives

To consider whether sleep problems in childhood and adolescence impact upon neurocognitive function and the subsequent development of chronic pain disorders. Using regression methods, results from the study will highlight whether poor sleep in adolescence will contribute increased rates of chronic pain conditions in later life.

It is expected that those with higher incidences of sleep problems will show reduced neurocognitive function. Links between these diminished functions and the development of chronic pain conditions will then be explored.

Hypotheses

Poor sleep will be associated with an increased level of chronic pain reports. Poor sleep will also result in diminished neurocognitive function. The association between sleep and chronic pain will attenuate after the control of neurocognitive function.

Exposure Variables

Early life/adolescent sleep problems

Outcome Variables

Chronic pain condition (y/n)?

Confounding Variables

Gender, socio-economic status, depression, neurocognitive function.