Objective: The purpose was to examine the psychometric properties of the Pre-Sleep Arousal Scale.

Methods: From a randomly selected sample of the general population (N = 5000), 2327 participants completed a survey on nighttime symptoms, daytime symptoms, health outcomes, and psychological processes. The study sample consisted of 1890 participants who did not fulfill criteria for a sleep disorder other than insomnia.

Results: Findings indicated that the PSAS did not produce an adequate factorial solution. When three problematic items were removed, the solution, accounting for 48.5% of the variance, improved (PSAS-13). One subscale, cognitive arousal (alpha = .88), consisted of five items (37.1%), and one subscale, somatic arousal (alpha = .72), of eight items (11.4%). The two factors were significantly inter-correlated (rho = .51) and associated with the PSAS-13 (rho = .91, rho = .80). Among those with insomnia, a shortened PSAS (PSAS-14) was established, which consisted of a cognitive and a somatic subscale (48.6% of the variance). The PSAS-13 and the two subscales showed discriminant validity between three sleep groups (normal sleep, poor sleep, and insomnia disorder) (R-2 = .24-.34). The PSAS-13 and the subscales demonstrated convergent validity with measures on sleep-related worry, sleep-related beliefs, anxiety, and depression. The PSAS-13 and the two subscales were significantly correlated with sleep parameters and daytime impairment.

Conclusion: Though acceptable psychometric properties were established for the PSAS, the cognitive sub-scale's focus upon general pre-sleep arousal and the relatively low variance accounted for calls for further work on and a possible re-conceptualization of the PSAS.

Objective: Worldwide there are frequent reports on increasing psychosomatic problems, anxiety, emotional distress, conduct problems, and depression among adolescents. Recently, it was contended that secular studies on such aspects of adolescent mental health can only be evaluated adequately when data on symptom prevalence are analyzed together with data on functional impairment Still, this has not yet been done in epidemiological time-trend studies on any aspect of adolescent mental health. Therefore, this study aims to investigate if, and to what extent, changes in adolescents' symptoms of psychosomatic problems are affected when data on functional impairment are taken into account simultaneously. Methods: A repeated cross-sectional population study relating self-reported symptoms of psychosomatic problems to functional impairment; covering the time-period 1988-2011 and including 19.823 adolescents 15-16 years old in eight cohorts in one geographically defined population (Varmland, Sweden). Results: The proportion of adolescents with psychosomatic problems had increased significantly from 1988 to 2005/2008. In all cohorts the proportion of girls with psychosomatic problems was significantly higher than the proportion of boys reporting symptoms. Over the same period, there was a corresponding significant increase of the proportion of participants with symptoms of psychosomatic problems in combination with functional impairment Adding functional impairment to the measure of psychosomatic problems decreased the prevalence rates, while the shapes of the trend-curves stayed congruent in form. Conclusion: The long-term pattern of increasing psychosomatic problems among adolescents remains evident, even when taking functional impairment data into account. Previously observed trends of a deteriorating adolescent mental health are thus consistent with this study. 

Objective: DSM-5 somatic symptom disorder (SSD) constitutes a major change for psychosomaticmedicine and psychiatry, as well as for epidemiological research in these fields. This studyinvestigates somatic symptoms and psychological concerns among adolescents in order tosystematically explore the relevance of SSD for general adolescent populations.

Methods: A crosssectionalpopulation-based design, with a symptoms-based strategy and a symptom-andpsychological-concerns-based strategy, was used to estimate the prevalence of somatic symptomsand psychological concerns in a general adolescent population (n=2476, mean age=16 years, 49%boys, 51% girls). Somatic symptoms and psychological concerns in relation to gender, and selfreportedmedical and psychiatric conditions were investigated. The association between somaticsymptoms, psychological concerns, and functional impairment in school-, family-, peer- and physicalactivities was studied.

Results: Reporting 3+ persistent distressing somatic symptoms wassignificantly more common than reporting one or more persistent distressing somatic symptom(s)combined with serious psychological concern. The prevalence of such complaints was significantlyhigher in girls. The proportion of medical and psychiatric conditions was highest in the groupreporting 3+ persistent distressing somatic symptoms combined with serious psychological concern.Belonging to this group most significantly increased odds ratios for functional impairment.

Conclusion: For large-scale studies on SSD, results suggest the use of measures based on multiplesomatic items in combination with psychological concerns, and a methodologically soundstandardized measure of functional impairment. To further enhance clinical decision-making, therelation of symptoms to functional impairment, and the substantial overlap of SSD with medical andpsychiatric conditions during adolescence should be addressed.

Objective: Adolescence is a time of change during which several health problems, such as pain problems, increase. Psychosocial mechanisms involved in this development, such as interpersonal stressors and worry, are still understudied, especially longitudinally. The first aim of this study was to investigate the prevalence of musculoskeletal pain in Swedish adolescents between the ages 13 and 15 using pain grades. The second aim was to study the role of peer-related stress, worry, and gender in the development of musculoskeletal pain problems over time. Methods: Adolescents in 18 public schools were followed from 7th to 9th grade (N = 1181) and answered self-report questionnaires at three time points. Prevalence was assessed at all three time points and a moderated mediation analysis investigated if peer-related stress in 7th grade predicted musculoskeletal pain two years later and if this relationship was mediated by worry in 8th grade. Gender was entered as a moderator. Results: In 7th grade, 8.4% of adolescents reported musculoskeletal pain with some functional impairment. In 8th and 9th grade around 10% of adolescents reported musculoskeletal pain problems, with girls reporting a higher prevalence than boys. Peer-related stress in 7th grade predicted musculoskeletal pain problems in 9th grade, mediated by worry in 8th grade. The mediation was moderated by gender: peer-related stress predicted worry for girls, but not for boys. Conclusion: Peer-related stress and worry seem to be involved in the development of pain over time. These factors should therefore be targeted in preventative interventions and during treatment.