Structure of sleep disturbances and its relation to symptoms of psychopathology: evidence for specificity

A large body of research has demonstrated general relations of sleep complaints with psychological disorders, including anxiety, depression, and dissociation/schizotypy. In contrast, very few studies have focused on the specificity of sleep complaints to daytime symptoms. Identifying sleep disturbances that show evidence of specificity is important for differential diagnosis and assessment. This study used the structure of selfreported sleep complaints as a framework for examining specificity. Comprehensive questionnaire and interview measures of sleep disturbance were submitted to factor analyses in students and psychiatric patients. These analyses revealed the presence of three well defined higher order factors: Lassitude, Insomnia, and Unusual Sleep Experiences. These factors were then correlated with interview and questionnaire measures of daytime symptoms. Lassitude was specific to dysphoria, whereas Insomnia had weaker, nonspecific relations with daytime symptoms. Fatigue, a component of Lassitude, showed the strongest evidence of specificity. Unusual Sleep Experiences was specific to symptoms of posttraumatic stress disorder (PTSD) and dissociation. In particular, the Nightmares component of Unusual Sleep Experiences was strongly related to PTSD and the Sleep Hallucinations component of Unusual Sleep Experiences was strongly related to dissociation. Abstract Approved: ____________________________________ Thesis Supervisor ____________________________________ Title and Department ____________________________________ DateApproved: ____________________________________ Thesis Supervisor ____________________________________ Title and Department ____________________________________ Date STRUCTURE OF SLEEP DISTURBANCES AND ITS RELATION TO SYMPTOMS OF PSYCHOPATHOLOGY: EVIDENCE FOR SPECIFICITY