Rising rates of mental health problems and nonsuicidal self-injury (NSSI) among adolescents highlight the need for preventive interventions and the lack of evidence regarding such measures. To date, few studies have investigated school-based prevention programs targeting NSSI. In this study, a whole-school preventive intervention was carried out at Swedish lower secondary schools and evaluated in a cluster-randomized controlled trial. The whole-school intervention included classroom-based modules focusing on mental health and NSSI directed at students, psychoeducational webinars on NSSI directed at parents and teachers, and a two-day workshop on NSSI and suicidality for school health staff. Data were collected from students (N = 183, age M = 14.17, SD = 0.55, 58% female) at baseline and three- and six-month post-intervention follow-ups. Analyses revealed a significant decrease in three-month NSSI frequency and a significant difference in mental health-related stigma awareness in the intervention group compared to controls. Regarding other outcomes (NSSI onset, attitudes toward help-seeking, perceived social support, health-related quality of life, emotion regulation and self-criticism), no significant effects were found. Effects moderated by gender and history of NSSI were found, underscoring that the outcomes of universal prevention are not always uniformly distributed. Main conclusions were that whole-school prevention can be effective in reducing NSSI frequency as well as affecting the awareness of mental health-related stigma.

Adolescent mental health is today a topic raising great concern, and reports of rising rates of mental health problems have led some to call the situation a mental health crisis. In parallel with this, there has been a realization that nonsuicidal self-injury (NSSI) is something affecting an increasingly large share of adolescents. The fact that resources are limited together with the knowledge of the burden of mental health problems have spurred a great interest in prevention. Schools are seen as arenas with great potential for deploying preventive interventions targeting adolescents. The available evidence for such interventions is, however, limited and there is a need to better understand how they could be more effective. The present thesis aims to contribute to the scientific knowledge about school-based mental health prevention by investigating the effects of a whole-school prevention program, to explore adolescents’ experiences of taking part in such a program and to shed light on heterogeneity among adolescents with a history of NSSI as well as mechanisms underlying engagement in NSSI.

In Study I, the aim was to investigate emotion regulation and trauma symptoms as potential mediators of the association between childhood abuse and NSSI. In a sample (N = 3,169) of data from community adolescents, mediation was investigated using structural equation modeling. Both emotion regulation and trauma symptoms were found to partly mediate the relationship between childhood abuse and NSSI, and together to mediate this association completely. Study conclusions were that emotion regulation and trauma symptoms seem to be what drives NSSI rather than experiences of childhood abuse themselves.

Study II aimed to investigate characteristics of the subgroups of adolescents acknowledging NSSI when answering a dichotomous yes/no question versus a checklist with NSSI behaviors, in a sample (N = 266) of community adolescents. These groups were found to be large and to differ from each other in several respects, with implications both in clinical and research settings. Further, cluster analysis was employed in order to identify subgroups among adolescents with NSSI and, finding such subgroups to be different from each other, it was concluded that there was a need for greater awareness of the heterogeneity within NSSI.

In Study III, the effects of a whole-school preventive intervention were evaluated in longitudinal data from the same sample as in Study II (N = 183 with complete data from three points of measurement), harnessing the cluster-randomized, controlled design of the overall project. Effects were found on NSSI frequency, which decreased at post-intervention, and on Stigma Awareness, which increased. Conclusions of Study III was that a whole-school preventive intervention can be effective in reducing NSSI frequency and in increasing adolescents’ awareness of mental health stigma.

Study IV was a qualitative group interview study employing thematic analysis in order to explore adolescents’ experiences of taking part in the whole-school preventive intervention as well as their perspectives on mental health. Key findings were the identification of a autonomy/help-seeking dilemma, and the perceived need of interventions targeting mental health among adolescents.

In conclusion, the present thesis adds to the knowledge about prevention targeting NSSI and mental health among adolescents by documenting effects of a whole-school prevention program. Further, the thesis provides insights related to school-based prevention, including adolescents’ experiences, information on NSSI measurement and subgroups among individuals with a history of NSSI.

Ungdomars psykiska hälsa är idag ett ämne som väcker stor oro, och rapporter om stigande förekomst av psykiska problem har fått somliga att kalla situationen för en psykisk hälsokris. Parallellt med detta har det vuxit fram en insikt om att icke-suicidalt självskadebeteende (eng. nonsuicidal self-injury; NSSI) är något som drabbar en allt större andel ungdomar. De begränsade resurserna tillsammans med kunskapen om bördan av psykiska problem har lett till ett stort intresse för förebyggande åtgärder. Skolor ses som arenor med stor potential för förebyggande insatser riktade till ungdomar. Evidensen för sådana insatser är dock begränsad och det finns ett behov av att bättre förstå hur de kan bli mer effektiva. Denna avhandling syftar till att bidra till den vetenskapliga kunskapen om skolbaserad psykisk hälsoprevention genom att undersöka effekterna av ett skolövergripande preventionsprogram (eng. whole-school prevention program), utforska ungdomars erfarenheter av att delta i ett sådant program och att belysa heterogenitet bland ungdomar med en historia av självskadebeteende samt mekanismer bakom självskadebeteende.

I Studie I var syftet att undersöka emotionsreglering och traumasymptom som potentiella mediatorer av sambandet mellan övergrepp i barndomen och självskadebeteende. I ett urval (N = 3169) av data från ungdomar undersöktes mediation med hjälp av strukturell ekvationsmodellering. Både emotionsreglering och traumasymptom visade sig delvis mediera sambandet mellan barndomsmisshandel och självskadebeteende, och tillsammans mediera de båda faktorerna detta samband fullständigt. Studiens slutsatser var att emotionsreglering och traumasymptom verkar vara det som driver självskadebeteende snarare än själva erfarenheterna av övergrepp.

Studie II syftade till att undersöka egenskaper hos de undergrupper av ungdomar som indikerar självskadebeteende genom svar på en dikotom ja/nej-fråga jämfört med en checklista med självskadebeteenden, i ett urval (N = 266) av ungdomar. Dessa grupper visade sig vara stora och skilja sig från varandra i flera avseenden, med implikationer både i kliniska och forskningssammanhang. Vidare användes klusteranalys för att identifiera undergrupper bland ungdomar med självskadebeteende, och eftersom det visade sig att sådana undergrupper skilde sig från varandra var en slutsats att det finns ett behov av större medvetenhet om heterogeniteten inom självskadebeteende.

I Studie III utvärderades effekterna av den skolövergripande preventiva insatsen med hjälp av longitudinella data från samma urval som i studie II (N = 183 med fullständiga data från tre mätpunkter) och genom den klusterrandomiserade, kontrollerade designen hos det övergripande projektet. Effekter observerades på frekvens av självskadebeteende, som minskade efter interventionen, och på medvetenhet om stigma, som ökade. Viktiga slutsatser från Studie III var att en skolövergripande preventiv intervention kan vara effektiv för att minska frekvensen av självskadebeteende och öka ungdomars medvetenhet om stigma kopplat till psykisk hälsa.

Studie IV var en kvalitativ gruppintervjustudie vari tematisk analys användes för att utforska ungdomars erfarenheter av att delta i den skolövergripande preventiva interventionen, samt deras perspektiv på psykisk hälsa. Viktiga resultat var noteringen av ett dilemma mellan autonomi och hjälpsökande, och det upplevda behovet av interventioner riktade mot psykisk hälsa bland ungdomar.

Sammanfattningsvis bidrar denna avhandling till kunskapen om förebyggande insatser med fokus på självskadebeteende och psykisk hälsa bland ungdomar genom att dokumentera effekterna av ett skolövergripande preventivt program. Vidare innehåller avhandlingen insikter relaterade till skolbaserad prevention, inklusive ungdomars erfarenheter, information om mätning av självskadebeteende samt subgrupper inom individer med självskadebeteende.

Background Programs for mental health promotion and prevention of nonsuicidal self-injury (NSSI) in schools have gained increased focus during the last decades, but less is known about adolescents’ experiences of such interventions.

Methods A whole-school preventive intervention targeting mental health and NSSI was delivered to six secondary schools. Adolescents participated in the Youth Aware of Mental Health program combined with an NSSI-focused psychoeducation module. Caregivers and teachers were given online psychoeducation on NSSI, and school health care staff were given a workshop on self-injury. Eleven group interviews (n = 65 participants) were conducted with adolescents (ages 13–15 years, 65% females) exploring participant experiences. Interviews were analyzed using thematic analysis and interpreted in light of a biopsychosocial understanding of adolescence.

Results The analysis generated two main themes. The first theme, Mental health in the context of adolescence, centered around adolescents’ conception of mental health, after having taken part in the intervention, framed in a context of coping with external stressors. The dilemma of autonomy versus help-seeking was also identified as part of the first main theme. The second theme, The who, when, what, and how of the intervention, described adolescents’ experiences of the intervention. This theme included increased awareness and knowledge of mental ill-health. The participants generally agreed that the topics included are important to adolescents and emphasized that the content needs to be relatable. Several factors that influence how a school-based program is received by adolescents were identified, such as who should be targeted and when. Adolescents also identified challenges and gave recommendations for future similar projects.

Conclusions Adolescents generally perceived addressing mental health and NSSI in schools as important. Help-seeking initiatives need to be balanced against adolescents’ need for autonomy when planning mental health prevention and intervention.

BackgroundNonsuicidal self-injury (NSSI) is highly prevalent in adolescents. In survey and interview studies assessing NSSI, methods of assessment have been shown to influence prevalence estimates. However, knowledge of which groups of adolescents that are identified with different measurement methods is lacking, and the characteristics of identified groups are yet to be investigated. Further, only a handful of studies have been carried out using exploratory methods to identify subgroups among adolescents with NSSI.MethodsThe performance of two prevalence measures (single-item vs. behavioral checklist) in the same cross-sectional community sample (n = 266, age M = 14.21, 58.3% female) of adolescents was compared regarding prevalence estimates and also characterization of the identified groups with lifetime NSSI prevalence. A cluster analysis was carried out in the same sample. Identified clusters were compared to the two groups defined using the prevalence measures.ResultsA total of 118 (44.4%) participants acknowledged having engaged in NSSI at least once. Of these, a group of 55 (20.7%) adolescents confirmed NSSI on a single item and 63 (23.7%) adolescents confirmed NSSI only on a behavioral checklist, while denying NSSI on the single item. Groups differed significantly, with the single-item group being more severely affected and having higher mean scores on difficulties in emotion regulation, self-criticism, number of methods, higher frequency of NSSI, higher rates of suicidal ideation and suicidal behavior and lower mean score on health-related quality of life. All cases with higher severity were not identified by the single-item question. Cluster analysis identified three clusters, two of which fit well with the groups identified by single-item and behavioral checklist measures.ConclusionsWhen investigating NSSI prevalence in adolescents, findings are influenced by the researchers' choice of measures. The present study provides some directions toward what kind of influence to expect given the type of measure used, both with regards to the size of the identified group and its composition. Implications for future research as well as clinical and preventive work are discussed.