Concurrent hierarchical linear regression analyses with insomnia symptoms as the dependent variable, and age, sex, parental criticism, anxiety and depression as predictors at baseline.

<p>Notes</p><p>*Significant for p-level < .05.</p><p>** Significant for p-level < .01.</p><p>Concurrent hierarchical linear regression analyses with insomnia symptoms as the dependent variable, and age, sex, parental criticism, anxiety and depression as predictors at baseline.</p

Concurrent hierarchical linear regression analyses with insomnia symptoms as the dependent variable, and age, sex, doubts about action, anxiety and depression as predictors at baseline.

<p>Notes</p><p>*Significant for p-level < .05.</p><p>** Significant for p-level < .01.</p><p>Concurrent hierarchical linear regression analyses with insomnia symptoms as the dependent variable, and age, sex, doubts about action, anxiety and depression as predictors at baseline.</p

Participant characteristics concerning ethnicity, work status and education level.

<p>Notes</p><p>N, Number of Participants; %, Percentage of Participants; Education, Highest Qualification Attained; GCSE, General Certificate of Secondary Education; HND, Higher National Diploma.</p><p>Participant characteristics concerning ethnicity, work status and education level.</p

Concurrent correlations between insomnia symptoms, anxiety, depression and perfectionism at baseline and follow-up.

<p>Notes</p><p>Baseline (n = 76) correlations are displayed below the diagonal; follow-up (n = 57) correlations are displayed above the diagonal.</p><p>ISI, Insomnia Severity Index; CM, Concern Over Mistakes; D, Doubts About Action; PE, Parental Expectations; PC, Parental Criticism; ORG, Organization; PS, Personal Standards, SOP, Self Oriented Perfectionism; OOP, Other Oriented Perfectionism; SPP, Socially Prescribed Perfectionism.</p><p>*Significant for p-level < .05.</p><p>** Significant for p-level < .01.</p><p>Concurrent correlations between insomnia symptoms, anxiety, depression and perfectionism at baseline and follow-up.</p

Longitudinal linear regression analyses with follow-up perfectionism as the dependent variables, and age, sex, baseline and follow-up insomnia severity, baseline anxiety and baseline depression as predictors.

<p>Notes</p><p>ISI, Insomnia Severity Index</p><p>*Significant for p-level < .05.</p><p>** Significant for p-level < .01.</p><p>Longitudinal linear regression analyses with follow-up perfectionism as the dependent variables, and age, sex, baseline and follow-up insomnia severity, baseline anxiety and baseline depression as predictors.</p

Mean scores and standard deviations (SD) for insomnia symptoms, anxiety, depression and perfectionism.

<p>Notes</p><p>Range: Min–Max; Insomnia Severity Index: Possible Range 0–28; Perfectionism: Concern Over Mistakes, Possible Range 9–45; Doubts About Action, 4–20; Parental Expectations, 5–25; Parental Criticism, 4–20; Organisation, 6–30; Personal Standards, 7–35; Self Oriented Perfectionism, 15–105; Other Oriented Perfectionism, 15–105; Socially Prescribed Perfectionism, 15–105; Hospital Anxiety & Depression Scale: Anxiety, Possible Range 0–21; Depression; 0–21.</p><p>Mean scores and standard deviations (SD) for insomnia symptoms, anxiety, depression and perfectionism.</p