Table 1.
Descriptive statistics and attrition analyses.
| Initial sample (N = 10,533) | Sample used in the profile analysis (n = 2860) | Sample used in the COVID analysis (n = 904) | Attrition analysis |
||||
|---|---|---|---|---|---|---|---|
| Profile |
COVID sample |
||||||
| t / χ2 | ES | t / χ2 | ES | ||||
| Sex (% female) | 50.2 | 54.51 | 70.8 | 28.89⁎⁎ | 0.05 | 0.01 | 0 |
| Ethnicity (% non-White Caucasian) | 15.6 | 3.3 | 2.44 | 430.12⁎⁎ | 0.20 | 103.10⁎⁎ | 0.07 |
| Baseline age (years) | 17.18 (0.34) | 17.18 (0.32) | 17.17 (0.32) | 1.05 | 0.02 | −1.12 | −0.05 |
| Distal factors | |||||||
| Heavy drinking (% yes) | 16.05 | 15.82 | 20.10⁎⁎ | 0.03 | |||
| Regular smoking (% yes) | 6.71 | 4.98 | 0.12 | 0 | |||
| Cannabis use | 131.78⁎⁎ | 0.08 | |||||
| No use | 64.2 | 66.04 | |||||
| Sporadic | 28.92 | 29.54 | |||||
| Regular | 6.89 | 4.42 | |||||
| Other drugs (% yes) | 6.29 | 4.31 | 13.86⁎⁎ | 0.03 | |||
| Being arrested (% yes) | 1.57 | 0.55 | 0.32 | 0.01 | |||
| Problematic video gaming (% yes) | 16.64 | 10.95 | 0.02 | 0 | |||
| Gambling (% yes) | 16.61 | 12.83 | 17.26⁎⁎ | 0.03 | |||
| Sleep quality (% bad) | 33.46 | 33.74 | 6.52⁎ | 0.02 | |||
| Self-harm (% yes) | 28.5 | 33.74 | 24 | 0.03 | |||
| Suicide attempt (% yes) | 8.53 | 8.85 | 9.96⁎⁎ | 0.02 | |||
| Mental health difficulties1 (% over 75th percentile) | 26.22 | 25.66 | 0.1 | 0 | |||
| Proximal factors | |||||||
| Outdoor spaces in house (% no) | 3.44 | 0.52 | 0.01 | ||||
| Change in household members (% yes) | 29.24 | 6.25⁎ | 0.02 | ||||
| Financial management (% worse management) | 26.75 | 0.01 | 0 | ||||
| Change in conflict level (% more conflict around) | 23.19 | 2.52 | 0.01 | ||||
| Change in perceived stress (% more feelings of stress) | 44.1 | 1.3 | 0.01 | ||||
| Change in sleep time2 | 1.34 (0.83) | −0.13 | −0.01 | ||||
| Change in smoking pattern3 | −0.5 (3.67) | 1.93 | 0.23 | ||||
| Change in drinking pattern4 | 0.08 (0.27) | −1.32 | −0.07 | ||||
| Social provisions5 | 8.41 (1.02) | 0.02 | 0 | ||||
| Loneliness6 | 7.14 (2.26) | −0.88 | −0.04 | ||||
| Mental wellbeing7 | 22.99 (4.82) | 0.95 | 0.04 | ||||
| Mental distress8 | 8.62 (5.03) | −1.61 | −0.07 | ||||
| Anxiety symptoms9 | 3.94 (1.81) | −1.58 | −0.07 | ||||
| Depressive symptoms10 | 3.98 (1.69) | −1.7 | −0.07 | ||||
Note. Percentage of cases are displayed for dichotomous and categorical variables. Mean and standard deviation (between brackets) are displayed for continuous variables. Attrition analysis involves comparing the variables of interest between: 1) the sample of profile analysis (n = 2860) and the sample dropped out (n = 7673) from the initial sample (Profile attrition analysis); 2) the sample used in the COVID impact analysis (n = 904) with the sample dropped out (n = 1956) from the psychopathology profile analysis (COVID sample attrition analysis). The t -based tests (continuous variables) and χ2 tests (dichotomous/categorical variables) were used as contrast test statistics. Effect size (ES) estimates were the Cohen's d for continuous variables and Cramer's V for non-continuous ones.
The distal factor data were collected when participants were 17 years old (in 2018). The proximal factor data were collected on May 2020 (in times of the COVID-19 pandemic) when the participants were 19 years old.
Derived from the Strength and Difficulties Questionnaire total scores.
Differences between sleep hours before and during the COVID-19 lockdown.
Difference in the number of cigarettes smoked per day before and during the COVID-19 lockdown.
Difference in the number of alcohol drinks before and during the COVID-19 lockdown.
Measured using the Social Provisions Scale.
Measured using the UCLA Loneliness Scale.
Measured using the Warwick-Edinburgh Mental Health and Wellbeing Scale.
Measured using the Kessler K6 Scale.
Measured using the 2-item Generalised Anxiety Disorder Scale.
Measured using the 2-item Patient Health Questionnaire.
p < .05.
p < .01.