Delayed Sleep Phase

Diagnosis

Delayed sleep phase (DSP) must be distinguished from normal sleep variations and from other sleep disorders. In addition to taking a medical history, doctors may use a variety of tools to gather information about a patient's sleep patterns in order to arrive at an accurate diagnosis:

• Epworth sleepiness questionnaire: Gauges levels of tiredness and effects on daily life
  
• Actigraphy: Tracks activity cycles in the home environment with a small device worn like a wristwatch
  
• Sleep diary: Logs daily sleep and wake times — used in conjunction with actigraphy
  
• Horne-Östberg questionnaire: Determines whether a patient is more of an "evening type" or "morning type"

If another sleep disorder is suspected, an overnight stay at a Mayo Clinic Sleep Center for polysomnogram testing may be recommended.