Assessment of Excessive Sleepiness and Insomnia as They Relate to Circadian Rhythm Sleep Disorders

Sleep disturbances are associated with a number of psychiatric disorders, including depression,anxiety disorders, and substance use disorders, and many psychiatric patients report symptoms suchas insomnia, tiredness, fatigue, and excessive sleepiness. Despite their known negative impact on daytimefunctioning and quality of life, less than 10% of individuals with these symptoms visit physiciansspecifically for their sleeping problems. Although there are many explanations for this lack of reporting,one possibility is that individuals are often unaware of the impact of sleepiness on their daytimefunctioning. Therefore, the burden of identifying sleepiness and its consequences often resides withphysicians and other health care professionals. This process of detection is assisted by rating scalesand subjective and objective tests. Although prior discussions on these topics have focused on the understandingand identification of either excessive sleepiness or insomnia, these symptoms often coexist,introducing a clinical challenge in that it becomes unclear which of these two should become theinitial focus of clinical attention. When both excessive sleepiness and insomnia coexist, a circadianrhythm sleep disorder may be present, such as jet lag type, delayed and advanced sleep phase types,and shift work type.