Table 1.
RCTs investigating cognitive effects of treating insomnia or sleep-disordered breathing
| Treatment (Publication Year) | Sample Characteristics | Sleep measure | Cognitive outcomes | Results |
|---|---|---|---|---|
| Insomnia | ||||
| BBTI (4 weeks) [47] (2016) | Community-dwelling older adults with insomnia (N = 79; mean age = 71.7; 68.3% female; 91.1% white) | Chronic insomnia (DSM-IV-TR) or general insomnia disorder (ICSD-2), verified by questionnaires and clinician interviews. | Episodic memory: Logical Memory Working memory: Letter-Number Sequencing Abstract reasoning: Test of Non-Verbal Intelligence |
No effect on cognition. |
| Adapted CBT-I (six, 1-hour sessions) [45] (2018) | Older adults with mild cognitive impairment and insomnia in two residential facilities (N = 28; mean age = 89.4; 85.7% female) | DSM-5 criteria for insomnia disorder. | Verbal memory: Hopkins Verbal Learning Test Executive function: Trail Making Test A and B Inhibition/switching: Delis Kaplan Executive Function System |
Improved inhibition, a subdomain of executive function. |
| BBTI (4 weeks) [46] (2018) | Community-dwelling older adults with insomnia (N = 62; mean age = 69.5 ± 7.7; 67.7% female; 82.3% white) | Insomnia complaints ≥3 nights/week for >6 months; sleep onset or awake time during night >30 min ≥ 6 nights during 2-week baseline period per sleep diary. | Overall cognitive functioning: Mini-Mental Status Exam, Wechsler Adult Intelligence Scale-III (vocabulary, digit symbol) Attention and Processing speed: Trail Making Test A Language: COWA (semantic verbal fluency), Boston Naming Test Memory: California Verbal Learning Test, Rey-Osterreith Complex Figure Test, Wechsler Memory Scale (logical memory) Executive function: COWA (phonemic fluency), Trail Making Test B |
No effect on cognition. |
| Sleep-Disordered Breathing | ||||
| CPAP (3 months) [48] (2015) | Older adults with newly diagnosed severe OSA syndrome (N = 33; mean age = 71.3 ± 5.5; 30.3% female) | Polysomnography | Memory: Rey Auditory Verbal Learning Test Attention: digit span forward Executive function: digit span backward, digit symbol substitution test, Trail Making Test A and B, verbal fluency |
Improved episodic and short-term memory, and processing speed. |
| CPAP (3 months) [49] (2019) | Older adults with moderate OSA (N = 145; mean age = 74.9 ± 4.6; 34.5% female) | PSG or respiratory polygraphy. | Executive function: Trail Making Test A and B Working memory: digit symbol substitution test, digit span backward |
No effect on cognition. |
Notes. BBTI = Brief Behavioral Treatment for Insomnia; CBT-I = Cognitive Behavioral Therapy for Insomnia; COWA = Controlled Oral Word Association; CPAP = continuous positive airway pressure; DSM-IV-TR = Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; DSM-5 = Diagnostic and Statistical Manual of Mental Disorders, 5th Edition; ICSD-2 = International Classification of Sleep Disorders, 2nd Edition; OSA = Obstructive Sleep Apnea; PSG = polysomnography.