Sleep architecture parameters as a putative biomarker of suicidal ideation in treatment-resistant depression.
Disturbed sleep may confer risk for suicidal behaviors. Polysomnographic (PSG) sleep parameters have not been systematically evaluated in association with suicidal ideation (SI) among individuals with treatment-resistant depression (TRD).



This secondary data analysis included 54 TRD individuals (N=30 with major depressive disorder (MDD) and N=24 with bipolar depression (BD)). PSG sleep parameters included Sleep Efficiency (SE), Total Sleep Time (TST), Wakefulness After Sleep Onset (WASO), REM percent/latency, and non-REM (NREM) Sleep Stages 1-4. The Hamilton Depression Rating Scale (HAM-D) was used to group participants according to presence or absence of SI. Sleep abnormalities were hypothesized among those with current SI. ANOVA analyses were conducted before (Model 1) and after adjusting for depression (Model 2) and diagnostic variables (Model 3).



Significant differences in PSG parameters were observed in Model 1; those with SI had less NREM Stage 4 sleep (p<.05). After adjusting for central covariates, Models 2 and 3 revealed significantly less NREM Stage 4 sleep, lower SE (P<.05), and higher WASO (P<.05) among those with SI. BD participants with SI also had less NREM Stage 4 and more NREM Stage 1 sleep.



1) a predominantly white sample; 2) exclusion of imminent suicide risk; 3) concomitant mood stabilizer use among BD patients; and 4) single-item SI assessment.



Independent of depression severity, SI was associated with less NREM Stage 4 sleep, and higher nocturnal wakefulness across diagnostic groups. Sleep may warrant further investigation in the pathogenesis of suicide risk, particularly in TRD, where risk may be heightened.
Suicide Prevention Research Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA. Electronic address: rbernert@stanford.edu.
Rebecca A
RA
Bernert
Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
David A
DA
Luckenbaugh
Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Wallace C
WC
Duncan
Suicide Prevention Research Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.
Naomi G
NG
Iwata
Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Elizabeth D
ED
Ballard
Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Carlos A
CA
Zarate
D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000150:complications / Q000523:psychology*; D003865:Major Depressive Disorder / Q000150:complications / Q000175:diagnosis; D061218:Depressive Disorder, Treatment-Resistant / Q000150:complications / Q000523:psychology*; D058068:Endophenotypes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications / Q000523:psychology*; D012894:Sleep Stages; D059020:Suicidal Ideation; D055815:Young Adult
Bipolar disorder; Depression; Sleep architecture; Suicide risk; Treatment-resistance