Table 1 Selection criteria

Inclusion criteria (combination of criteria from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), Insomnia Research Diagnostic Criteria, and International Classification of Sleep Disorders, 2nd edition

▪ Males and females age ≥ 21 years

▪ Complaint of persistent (that is, > 1 month) difficulties initiating or maintaining sleep despite adequate opportunity for sleep

▪ Sleep onset latency or wake time after sleep onset ≥ 30 minutes for three or more nights per week during 2 weeks of sleep diary monitoring

▪ Insomnia Severity Index (ISI) total score > 10, indicating at least “mild” insomnia

▪ Score ≥ 2 on either the interference or distress item of the screening ISI, indicating the insomnia causes significant distress or impairment in social, occupational, or other areas of functioning

Exclusion criteria

▪ Untreated psychiatric disorder (for example, major depression), as these conditions have specific treatments and it would be inappropriate not to offer those treatments

▪ Lifetime diagnosis of any psychotic or bipolar disorder, as sleep restriction and medications for insomnia may precipitate mania and hallucinations

▪ Imminent risk for suicide

▪ Alcohol or drug abuse within the past year

▪ Terminal or progressive physical illness (for example, cancer or COPD) or neurological degenerative disease (for example, dementia)

▪ Current use of medications known to cause insomnia (for example, steroids)

▪ Sleep apnea (apnea/hypopnea index > 15), restless legs syndrome, periodic limb movement during sleep (PLMS with arousal > 15 per hour), or a circadian rhythm sleep disorder (for example, advanced sleep phase syndrome)

▪ Personal or familial (first-degree relatives) history of sleepwalking

▪ Women being pregnant or expecting to become pregnant during treatment