As a result of this, individuals with this disorder will usually experience a gradual yet predictable delay of sleep onset and waking times. Patients with DSPD may develop this disorder if their condition is untreated. Extrinsic
Shift work sleep disorder (SWSD): Approximately 9% of Americans who work night or irregular work shifts are believed to experience shift work sleep disorder. Night shift work directly opposes the environmental cues that entrain our biological clock, so this disorder arises when an individuals clock is unable to adjust to the socially imposed work schedule. Shift work sleep disorder can lead to severe cases of insomnia as well as excessive daytime sleepiness. Jet lag: Jet lag is best characterized by difficulty falling asleep or staying asleep as a result of misalignment between ones internal circadian system and external, or environmental cues. It is typically associated with rapid travel across multiple time zones. Alzheimers disease
CRSD has been frequently associated with excessive daytime sleepiness and nighttime insomnia in patients diagnosed with Alzheimers disease (AD), representing a common characteristic among AD patients as well as a risk factor of progressive functional impairments. On one hand, it has been stated that people with AD have melatonin alteration and high irregularity in their circadian rhythm that lead to a disrupted sleep-wake cycle, probably due to damage on hypothalamic SCN regions typically observed in AD. On the other hand, disturbed sleep and wakefulness states have been related to worsening of an AD patients cognitive abilities, emotional state and quality of life.
Patients diagnosed with circadian rhythm sleep disorders typically express a pattern of disturbed sleep, whether that be excessive sleep that intrudes on working schedules and daily functions, or insomnia at desired times of sleep. Note that having a preference for extreme early or late wake times are not related to a circadian rhythm sleep disorder diagnosis. There must be distinct impairment of biological rhythms that affects the persons desired work and daily behavior. For a CRSD diagnosis, a sleep specialist gathers the history of a patients sleep and wake habits, body temperature patterns, and dim-light melatonin onset (DLMO). Gathering this data gives insight into the patients current schedule, as well as the physiological phase markers of the patients biological clock.The start of the CRSD diagnostic process is a thorough sleep history assessment. A standard questionnaire is used to record the sleep habits of the patient, including typical bedtime, sleep duration, sleep latency, and instances of waking up. The professional will further inquire about other external factors that may impact sleep. Prescription drugs that treat mood disorders like tricyclic antidepressants, selective serotonin reuptake inhibitors and other antidepressants are associated with abnormal sleep behaviors. Other daily habits like work schedule and timing of exercise are also recorded—because they may impact an individuals sleep and wake patterns. To measure sleep variables candidly, patients wear actigraphy watches that record sleep onset, wake time, and many other physiological variables.