Psychological Aspects of Sleep Disorders Research Paper

2. Background

Historically, sleep has not been an area of concern in psychology. Aside from psychoanalytic theory, which placed a good deal of emphasis on the role of unconscious motivation in explaining behavior, most psychological theory was based on behavior that was objectively observable. With the discovery in the early 1950s of rapid eye movement (REM) sleep, and its close association with the distinctive mental activity, dreaming, a good deal of work was undertaken to explore whether and how this interacted with waking behavior. The question of whether dreaming has some unique psychological function was driven by the observation that this phenomenon was universal, regularly recurring, and persistent when experimentally suppressed.

Initially it was speculated that the study of dreaming might lead to better understanding of the psychoses. Was the hallucination of mental illness a misplaced dream? Was the high degree of brain activation in REM sleep conducive to memory consolidation of new learning? Did dreaming play a role in emotional adaptation? When, after some 25 years of experimentation, no clear consequences for waking behavior could be attributed to the suppression of REM sleep, interest in this area faded. Loss of REM sleep did not appear to interfere with memory consolidation, nor did it promote waking hallucinations. Its role in emotional adaptation remained speculative. Foulkes’s (1982) study of children’s dream development concluded that dream construction was not something special. It could be explained by the periodic internal activation of the brain stimulating bits of sensory memory material represented at the same level of cognitive sophistication as the child was capable of achieving in waking thought. Adult dreams were further diminished in importance by the Activation-Synthesis hypothesis of Hobson and McCarley (1977), whose work pinpointed the area of the brain where REM sleep turns on as, not where the higher mental processes take place, but in the lower brain stem. In this theory dreams only acquire meaning after the fact, by association to what are initially, unplanned, random sensory stimuli.

3. Current Research

Interest in the 24-hour mind, the interaction of waking–sleeping–waking behavior came back into focus with the development of the field of sleep disorder medicine. The impact of disordered sleep on psychological functioning is documented most convincingly through large epidemiological studies of insomnia and hypersomnia that involved extensive follow up. The findings of Ford and Kamerow (1989) that both insomnia and hypersomnia are significant risk factors for new psychiatric disorders have now been replicated in several large studies. Further work has established that the onset of a new episode of waking major depression can be predicted from the presence of two weeks of persistent insomnia (Perlis et al. 1997). These findings have sparked the development of psychological interventions for the control of insomnia in an effort to prevent the development of these psychiatric disorders. Some of these are behavioral programs that work directly to manipulate sleep to improve its continuity, others are psychotherapeutic in nature such as interpersonal therapy and cognitive behavioral therapy which address the interaction patterns, emotional and cognitive styles that are dysfunctional in depressed persons.

Again, it was the observation that morning mood on awakening in major depression was frequently low, that suggested an investigation of the REM sleep and dreaming of the depressed person to test whether defects in this system prevented overnight mood regulation or emotional adaptation. The work of Kupfer and his colleagues (Reynolds and Kupfer 1987) established that there are several REM sleep deviations associated with major depression not seen in normal individuals. This leads to a variety of manipulations in an attempt to correct these. Vogel’s (Vogel et al. 1975) studies of extensive REM deprivation interspersed with recovery nights were most successful in improving waking mood and in bringing about remission without further treatment. Cartwright’s work (Cartwright et al. 1998) on the effect on morning mood of various within-night dream affect patterns, showed that a ‘working through’ pattern, from dreams expressing negative mood to those with predominantly positive affect, predicted later remission from depression.

The recurring nightmares characteristic of posttraumatic stress disorder (PTSD) has stimulated renewed interest in addressing dreams directly in treatment programs, especially for those with long-lasting symptoms of this disorder. These methods typically involve active rehearsal of mastery strategies for the control of the disturbing dream scenario.

A good deal of effort is now being addressed to discovering those attitudes, beliefs, and habitual behaviors that are implicated in maintaining poor sleep patterns since the correction of these may help to restore normal sleep and abort the development of a major psychiatric disorder.

Studies of the psychological profiles of those exhibiting various sleep disorders have most often employed the Minnesota Multiphasic Personality Inventory (MMPI). These show insomnia patients have more scale elevations above the norms especially of those indicating neurotic personality characteristic, such as phobias and obsessive compulsive disorders, than do matched controls. Generally, insomnia patients appear to internalize tensions rather than express them and may often somaticize these and express them as pain syndromes. In terms of demographic variables most studies report more women than men complain of insomnia. Rates are higher in those who are separated or widowed rather than single or married, and among the unemployed. In addition, insomnia is more common in those of middle to lower socioeconomic status than in the highest class. This picture suggests that a loss of the time structure of work and of a love relationship may be precipitating psychological factors in disrupting sleep wake rhythms.

Other sleep disorders, such as periodic limb movements of sleep, and sleep-related breathing disorders, are not related to personality, but do have an impact on relationships, due to an inability to share the bed at night, and on waking performance. Severe levels of any sleep disorder, whether insomnia or hypersomnia, limits work efficiency, cognitive clarity, and emotional stability.

4. Methodological Issues

Technological problems still hamper the progress in this field. Sleep laboratory studies are expensive and in many ways unnatural. Home studies while possible are unable to make repairs or adjustments as needed. Subjects must be awakened to obtain reports of their ongoing mental activity to investigate dream content. This aborts the end of each REM period, thus truncating the dream story. Dream reports are also limited by the subject’s ability to translate his/her sensory experience during sleep into waking verbal terms.

Recent studies using positive emission tomography (PET) to image the brain activity during REM sleep have established that dreaming sleep differs from waking and from non-REM in the activation of the limbic and paralimbic systems in the presence of lower activity in the dorsal–lateral frontal areas (Maquet et al. 1996, Nofzinger et al. 1997). This is interpreted as confirming that dreaming engages the emotional and drive-related memory systems in the absence of higher systems of planning and executive control. This gives new impetus to the study of dreams as a unique mental activity whose place in the 24-hour psychology may now move ahead on firmer ground.

5. Probable Future Directions

Work initiated by Solms (1997) on the effect of localized brain lesions on dream characteristics suggests a new line of investigation in mapping how the brain constructs dreams. This strategy may give more power to understand some of the dream disorders currently less well understood; perhaps even the hallucinations of psychoses.

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