Introduction
Cognitive style
Dissociation
Psychotic-like experiences
Behavioural patterns
The current study
Method
Participants
Measures
Demographics
Procedure
Statistical analysis
Results
Demographics
Nightmares (n = 381) | Control group (n = 465) |
χ
2
|
df
|
p
| |
---|---|---|---|---|---|
Sex, n
| |||||
Male | 39 | 55 | 0.5 | 1 | 0.464 |
Female | 342 | 410 | |||
Ethnicity, n
| |||||
White | 358 | 450 | 3.8 | 1 | 0.050 |
Any other | 23 | 15 | |||
Cocaine, n
| |||||
Yes | 22 | 15 | 3.24 | 1 | 0.071 |
No | 359 | 450 | |||
Cannabis, n
| |||||
Yes | 70 | 47 | 12.00 | 1 | 0.001** |
No | 311 | 418 | |||
Insomnia, n
| |||||
Not clinically significant | 66 | 185 | 50.64 | 1 | <0.001*** |
Clinically significant | 315 | 280 |
Nightmares (n = 381) | Control group (n = 465) | Odds ratio |
p
| 95% CI | |
---|---|---|---|---|---|
Marital status | |||||
Single | 129 | 125 | Reference | ||
Cohabiting | 60 | 46 | 1.264 | 0.314 | 0.801, 1.994 |
Married | 155 | 221 | 0.680 | 0.018* | 0.493, 0.936 |
Divorced | 32 | 55 | 0.564 | 0.025* | 0.342, 0.930 |
Widowed | 5 | 18 | 0.269 | 0.012* | 0.097, 0.747 |
Employment status, n
| |||||
Employed | 231 | 294 | Reference | ||
Retired | 43 | 75 | 0.730 | 0.134 | 0.483, 1.102 |
Student | 80 | 67 | 1.520 | 0.026* | 1.052, 2.195 |
Housewife/husband | 16 | 13 | 1.566 | 0.242 | 0.739, 3.322 |
Unemployed | 11 | 16 | 0.875 | 0.739 | 0.398, 1.922 |
Unadjusted associates of nightmares
Variable | Nightmares (n = 381) Mean (SD) | Control group (n = 465) Mean (SD) |
t
| ES (d) |
df
|
p
|
---|---|---|---|---|---|---|
Age | 41.4 (16.1) | 46.8 (15.3) | 5.4 | 0.3 | 844 | <0.001*** |
Negative affect | 48.1 (16.5) | 39.4 (11.9) | −8.9 | 0.6 | 844 | <0.001*** |
Worry | 52.8 (13.9) | 44.4 (14.1) | −8.3 | 0.6 | 844 | <0.001*** |
Depersonalisation | 46.4 (16.6) | 38.4 (12.4) | −8.0 | 0.5 | 844 | <0.001*** |
Hallucination | 15.3 (8.1) | 12.1 (5.2) | −3.6 | 0.5 | 844 | <0.001*** |
Paranoia | 31.2 (17.6) | 23.7 (12.3) | −7.5 | 0.5 | 844 | <0.001*** |
Alcohol use | 20.0 (9.2) | 20.1 (8.5) | 0.2 | <0.1 | 844 | 0.832 |
Activity level | 15.5 (4.3) | 15.6 (4.1) | 0.1 | <0.1 | 844 | 0.806 |
Sleep duration | 7.6 (1.3) | 7.3 (1.2) | −0.3 | 0.2 | 844 | 0.002** |
PTSD | 1.3 (1.5) | 0.7 (1.1) | −0.6 | 0.7 | 844 | <0.001*** |
Life events | 223.6 (151.5) | 163.1 (122.3) | −60.5 | 0.4 | 844 | <0.001*** |
Variable | Nightmare severity |
---|---|
Negative affect | 0.56, p < 0.001*** |
Worry | 0.45, p < 0.001*** |
Depersonalisation | 0.58, p < 0.001*** |
Hallucination | 0.49, p < 0.001*** |
Paranoia | 0.52, p < 0.001*** |
Alcohol use | 0.01, p = 0.810 |
Sleep duration | −0.14, p = 0.005** |
Activity level | −0.06, p = 0.280 |
PTSD | 0.50, p < 0.001*** |
Life events | 0.26, p < 0.001*** |
Adjusted analysis controlling for negative affect, PTSD symptoms and stressful life events
Worry
Adjusted for negative affect | Adjusted for negative affect and PTSD symptoms | Adjusted for negative affect, PTSD symptoms, and life events | |||||||
---|---|---|---|---|---|---|---|---|---|
Odds ratio |
p
| 95% CI | Odds ratio |
p
| 95% CI | Odds ratio |
p
| 95% CI | |
Worry | 1.45 | <0.001*** | 1.21, 1.73 | 1.40 | <0.001*** | 1.16, 1.17 | 1.38 | 0.001** | 1.15, 1.66 |
Depersonalisation | 1.33 | 0.006** | 1.08, 1.63 | 1.25 | 0.037* | 1.01, 1.54 | 1.21 | 0.073 | 0.98, 1.50 |
Hallucination | 1.40 | <0.001*** | 1.17, 1.67 | 1.34 | 0.001** | 1.12, 1.61 | 1.30 | 0.004** | 1.09, 1.56 |
Paranoia | 1.25 | 0.020* | 1.04, 1.51 | 1.18 | 0.100 | 0.97, 1.43 | 1.14 | 0.185 | 0.94, 1.39 |
Alcohol use | 0.99 | 0.370 | 0.98, 1.01 | 0.99 | 0.450 | 0.98, 1.01 | 0.99 | 0.510 | 0.98, 1.01 |
Sleep duration | 1.34 | <0.001*** | 1.15, 1.55 | 1.35 | <0.001*** | 1.16, 1.57 | 1.35 | <0.001*** | 1.16, 1.58 |
Activity level | 1.05 | 0.550 | 0.91, 1.21 | 1.04 | 0.600 | 0.90, 1.20 | 1.02 | 0.730 | 0.89, 1.19 |
Adjusted for negative affect | Adjusted for negative affect and PTSD symptoms | Adjusted for negative affect, PTSD symptoms, and life events | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
b
| SE |
p
|
R
2
| 95% CI |
b
| SE |
p
|
R
2
| 95% CI |
b
| SE |
p
|
R
2
| 95% CI | |
Worry | 0.07 | 0.018 | <0.001*** | 0.33 | 0.03, 0.10 | 0.06 | 0.018 | 0.004** | 0.41 | 0.02, 0.09 | 0.06 | 0.017 | 0.004** | 0.41 | 0.02, 0.09 |
Depersonalisation | 0.12 | 0.016 | <0.001*** | 0.39 | 0.08, 0.15 | 0.10 | 0.016 | <0.001*** | 0.45 | 0.06, 0.13 | 0.09 | 0.016 | <0.001*** | 0.45 | 0.06, 0.13 |
Hallucination | 0.09 | 0.013 | <0.001*** | 0.39 | 0.06, 0.11 | 0.08 | 0.012 | 0.001** | 0.45 | 0.05, 0.10 | 0.08 | 0.012 | 0.001** | 0.45 | 0.05, 0.10 |
Paranoia | 0.09 | 0.015 | <0.001*** | 0.36 | 0.06, 0.11 | 0.06 | 0.015 | <0.001*** | 0.42 | 0.03, 0.09 | 0.06 | 0.015 | <0.001*** | 0.42 | 0.03, 0.09 |