Table 2. Insomnia and cognitive arousal predicting depression one and two years later.
| b | ES | 95% CI | sig. | |
|---|---|---|---|---|
| Model 1: Depressive Symptoms at 1y | β | |||
| Age | -.02 | -.08 | −.03–−.01 | < .01 |
| Female Gender | .36 | .06 | .04–.68 | .03 |
| Major Life Events | .22 | .13 | .12–.32 | < .001 |
| Nocturnal Wakefulness | .01 | .10 | .01–.02 | < .001 |
| Cognitive Arousal | .09 | .19 | .06–.12 | < .001 |
| Model 2: Depression Status at 1y | OR | |||
| Age | -.02 | .98 | .96–1.01 | .13 |
| Female Gender | .80 | 2.22 | 1.06–4.64 | .03 |
| Major Life Events | .26 | 1.30 | 1.12–1.50 | < .001 |
| Non-perseverators with insomnia | .24 | 1.27 | .40–4.06 | .69 |
| Perseverators with good sleep | .61 | 1.85 | .87–3.92 | .11 |
| Perseverators with insomnia | .82 | 2.27 | .94–5.49 | .07 |
| Model 3: Depressive Symptoms at 2y | β | |||
| Age | −.00 | −.01 | −.02–.01 | .69 |
| Female Gender | −.02 | −.12 | −.39–.34 | .91 |
| Major Life Events | .14 | .08 | .02–.25 | .02 |
| Nocturnal Wakefulness | .02 | .13 | .01–.02 | < .001 |
| Cognitive Arousal | .09 | .20 | .06–.12 | < .001 |
| Model 4: Depression Status at 2y | OR | |||
| Age | -.02 | .99 | .96–1.01 | .27 |
| Female Gender | -.32 | .73 | .33–1.60 | .55 |
| Major Life Events | .07 | 1.07 | .85–1.35 | .55 |
| Non-perseverators with insomnia | -.61 | .54 | .07–4.43 | .57 |
| Perseverators with good sleep | .87 | 2.38 | .94–5.98 | .07 |
| Perseverators with insomnia | 1.23 | 3.43 | 1.15–10.21 | .03 |
| Model 5: Depression Status at 1y or 2y | OR | |||
| Age | -.01 | .99 | .97–1.01 | .28 |
| Female Gender | .11 | 1.12 | .59–2.12 | .74 |
| Major Life Events | .18 | 1.19 | 1.01–1.41 | .04 |
| Non-erseverators with insomnia | .04 | 1.04 | .28–3.80 | .96 |
| Perseverators with good sleep | .87 | 2.38 | 1.13–5.00 | .02 |
| Perseverators with insomnia | 1.28 | 3.61 | 1.54–8.48 | < .01 |
Notes: Models 2, 4, and 5 employ dummy coding to compare groups of perseverators and poor sleepers to the reference group consistent of non-perseverating good sleepers. Depressive Symptoms measured by the Quick Inventory of Depressive Symptomatology (QIDS) 16-item version. Depression Status also measured by the QIDS with scores < 10 conferring a negative screen, and scores ≥ 10 indicating a positive depression screen. 1y = one year after baseline. 2y = two years after baseline. b = beta, i.e., unstandardized regression coefficient. ES = effect size, referring to β (standardized regression coefficients) for linear regression models and OR (Odds-Ratio) for logistic regression, as denoted in the column. CI = confidence interval, which represents the 95% CI around b (linear models) and OR (logistic models). sig. = p-value indicating statistical significance.