They concluded that ADHD may be one of the consequence of nightmares but is not an outcome of it. This study is valuable to my study in that it teaches me to be skeptical regarding differentiating between outcome and cause.

4.

StRanjbaran, Z., Keefer, L., Farhadi, a., Stepanski, E., Sedghi, S. And Keshavarzian, a. (2007), Impact of sleep disturbances in inflammatory bowel disease. Journal of Gastroenterology and Hepatology, 22: 1748 -- 1753.

Study showed that inflammatory bowel disease (IBD) patients have significant sleep disturbance even when their disease is not active. This problem might affect quality of life, gastrointestinal symptoms and coping ability, and might potentially increase or decrease disease severity. A self-administered, mail-in questionnaire package was sent to 205 subjects using the Pittsburgh Sleep Quality Index (PSQI), a measure of disease severity and the IBD-Quality of Life Questionnaire. Interestingly enough, both IBD and irritable bowel syndrome (IBS) subjects thought that sleep and their disease status were correlated.

The tools are reliable although questionnaires are always riddled with problems. Sleep disturbances too may come from another cause or may be an outcome rather than determinant of IBD. Either way, sleep disturbances certainly impact QOL and therefore, it is argued, may have impact on body. In this way, this study coheres with the other studies used for my report and is helpful.

5.

Smith M.T., Haythornthwaite J.A. (2004). How do sleep disturbance and chronic pain inter-relate? Insights from the longitudinal and cognitive-behavioral clinical trials literature Sleep Medicine Reviews, 8 (2), pp....

One of the elements of sleep disturbances -- in fact an integral part o if it -- is nightmares. This literature review suggests that the relationship between nightmares / sleep disturbances and chronic illness is reciprocal in that nightmares aggravate chronic illness, whereas chronic illness frequently eventuates in nightmares.
This literature review is a welcome addition to previous mentioned studies bringing clarification on the point.

6.Pilowsky I., Crettenden I., Townley M. (1985) Sleep disturbance in pain clinic patients Pain, 23 (1), pp. 27-33.

Reported sleep disturbances seem to significantly account for psychological differences of QOL in chronically ill patients. One hundred out-patients, referred to a multidisciplinary pain clinic for the management of chronic pain, were questioned regarding their sleeping habits and were grouped according to whether they reported 'good,' 'fair' or 'poor' sleep. All patients were administered questionnaires to measure illness behavior, depression and anxiety. 'Good' and 'poor' sleepers differed on most measures, particularly depression, pain intensity, activity levels and hypochondriasis.

Researchers concluded that sleep impairments (including nightmares) could serve as an index on impairment and psychological performance.

This study has the same criteria as most of the previous studies, namely reliability of instruments but unrealistically of self-report. Nonetheless, it is helpful in that it adds to previous studies and distinguishes between psychological and physical impediment.