Sebastian Hökby

Mr. Sebastian Hökby

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 July 2016 in JMIR Mental Health
Verified
Journal Article
Open access
SHSebastian Hökby
Sebastian Hökby
GHGergö Hadlaczky
Gergö Hadlaczky
JWJoakim Westerlund
Joakim Westerlund
DWDanuta Wasserman
Danuta Wasserman
JBJudit Balazs
Judit Balazs
VCVladimir Carli
Vladimir Carli
Background: Adolescents and young adults are among the most frequent Internet users, and accumulating evidence suggests that their Internet behaviors might affect their mental health. Internet use may impact mental health because certain Web-based content could be distressing. It is also possible that excessive use, regardless of content, produces negative consequences, such as neglect of protective offline activities. Objective: The objective of this study was to assess how mental health is associated with (1) the time spent on the Internet, (2) the time spent on different Web-based activities (social media use, gaming, gambling, pornography use, school work, newsreading, and targeted information searches), and (3) the perceived consequences of engaging in those activities. Methods: A random sample of 2286 adolescents was recruited from state schools in Estonia, Hungary, Italy, Lithuania, Spain, Sweden, and the United Kingdom. Questionnaire data comprising Internet behaviors and mental health variables were collected and analyzed cross-sectionally and were followed up after 4 months. Results: Cross-sectionally, both the time spent on the Internet and the relative time spent on various activities predicted mental health (P<.001), explaining 1.4% and 2.8% variance, respectively. However, the consequences of engaging in those activities were more important predictors, explaining 11.1% variance. Only Web-based gaming, gambling, and targeted searches had mental health effects that were not fully accounted for by perceived consequences. The longitudinal analyses showed that sleep loss due to Internet use (ß=.12, 95% CI=0.05-0.19, P=.001) and withdrawal (negative mood) when Internet could not be accessed (ß=.09, 95% CI=0.03-0.16, P<.01) were the only consequences that had a direct effect on mental health in the long term. Perceived positive consequences of Internet use did not seem to be associated with mental health at all. Conclusions: The magnitude of Internet use is negatively associated with mental health in general, but specific Web-based activities differ in how consistently, how much, and in what direction they affect mental health. Consequences of Internet use (especially sleep loss and withdrawal when Internet cannot be accessed) seem to predict mental health outcomes to a greater extent than the specific activities themselves. Interventions aimed at reducing the negative mental health effects of Internet use could target its negative consequences instead of the Internet use itself. Trial Registration: International Standard Randomized Controlled Trial Number (ISRCTN): 65120704; http://www.isrctn.com/ISRCTN65120704?q=&filters=recruitmentCountry:Lithuania&sort=&offset= 5&totalResults=32&page=1&pageSize=10&searchType=basic-search (Archived by WebCite at http://www.webcitation/abcdefg)

2 April 2025 in PLOS Global Public Health
Verified
Journal Article
Open access
SHSebastian Hökby
Sebastian Hökby
JAJesper Alvarsson
Jesper Alvarsson
JWJoakim Westerlund
Joakim Westerlund
VCVladimir Carli
Vladimir Carli
GHGergö Hadlaczky
Gergö Hadlaczky
Recently the Swedish Public Health Agency published recommendations of a maximum of two-to-three hours of daily leisure screen time for adolescents aged 13–18, partly to promote better sleep (2024-Sep-02). Biologically and socially, adolescence is characterized by belated sleep times, and depressive effects of screen time can arise through sleep displacements. Theorized links between screen time, sleep, and depression, merited examination of four sleep mediators to determine their relative importance and determine which of them mediate future depression. Hypotheses were preregistered. Three-wave psychometric health data were collected from healthy Swedish students (N = 4810; 51% Boys; ages 12–16; N = 55 schools; n = 20 of 26 Stockholm municipalities). Multiple imputation bias-corrected missing data. Gender-wise Structural Equation Modelling tested four sleep facets as competing mediators (quality, duration, chronotype, social jetlag). The primary model result included the three first mediators to achieve acceptable fit indices (RMSEA = 0.02; SRMR = 0.03; CFI = 0.95; TLI = 0.94). Screen time deteriorated sleep within three months and effect sizes varied between mediators (Beta weights ranged: 0.14–0.30) but less between genders. Among boys, screen time at baseline had a direct adverse effect on depression after twelve months (Beta = 0.02; p <0.038). Among girls, the depressive effect was mediated through sleep quality, duration, and chronotype (57, 38, 45% mediation). Social jetlag remained non-significant. This study supports a modernized ‘screen-sleep-displacement theory’. It empirically demonstrates that screen-sleep displacements impact several aspects of sleep simultaneously. Displacements led to elevated depressive symptoms among girls but not boys. Boys may be more prone to externalizing symptoms due to sleep loss. Results could mirror potentially beneficial public health effects of national screen time recommendations.

2 November 2023 in PLOS ONE
Verified
Journal Article
Open access
PDF file
TLTheresa Lemke
Theresa Lemke
SHSebastian Hökby
Sebastian Hökby
DWDanuta Wasserman
Danuta Wasserman
VCVladimir Carli
Vladimir Carli
GHGergö Hadlaczky
Gergö Hadlaczky
Objective: To investigate behavioral sleep habits, self-perceived quality of sleep, and chronotype, and to examine their association with clinically relevant levels of depression in Swedish adolescents.Method: Questionnaire data were obtained from a representative sample of Swedish adolescents (n = 8449; 50.8% girls; aged 12–16). Depression was defined as >13 BDI-II scores. Logistic regression modelling estimated the effects of sleep duration, sleep quality, and chronotype on depression, adjusted for socio-demographic factors.Results: On weekdays, approximately 46% of adolescents slept less than the recommended length of eight hours per night (depressed: 68%, non-depressed: 40%). On weekends, however, only 17% slept shorter than recommended. Short weekday sleep duration was more common among girls than boys (53% vs. 38%) and girls reported worse sleep quality. The regression model showed that depression was predicted by weekday sleep duration (OR = 0.773, p < .0001), sleep quality (OR = 0.327, p < .0001), and late chronotype (OR = 1.126, p = .0017), but not by weekend sleep duration. A 30-minute increase in weekday sleep duration was associated with about 10% lower odds of depression.Conclusions: A substantial proportion of Swedish adolescents do not seem to meet the sleep recommendations of eight hours per night. Short sleep duration on weekdays, poor sleep quality, and late chronotype were associated with increased risk of depression. Interventions promoting longer weekday sleep duration (e.g., later school start times) seem relevant in this context, but further research is needed to investigate the directionality and underlying mechanisms of these associations.

SHSebastian Hökby
Sebastian Hökby
JWJoakim Westerlund
Joakim Westerlund
JAJesper Alvarsson
Jesper Alvarsson
VCVladimir Carli
Vladimir Carli
GHGergö Hadlaczky
Gergö Hadlaczky
Studies suggest that hourly digital screen time increases adolescents’ depressive symptoms and emotional regulation difficulties. However, causal mechanisms behind such associations remain unclear. We hypothesized that problem-focused and/or emotion-focused engagement coping moderates and possibly mediates this association over time. Questionnaire data were collected in three waves from a representative sample of Swedish adolescents (0, 3 and 12 months; n = 4793; 51% boys; 99% aged 13–15). Generalized Estimating Equations estimated the main effects and moderation effects, and structural regression estimated the mediation pathways. The results showed that problem-focused coping had a main effect on future depression (b = 0.030; p < 0.001) and moderated the effect of screen time (b = 0.009; p < 0.01). The effect size of this moderation was maximum 3.4 BDI-II scores. The mediation results corroborated the finding that future depression was only indirectly correlated with baseline screen time, conditional upon intermittent problem-coping interference (C’-path: Std. beta = 0.001; p = 0.018). The data did not support direct effects, emotion-focused coping effects, or reversed causality. We conclude that hourly screen time can increase depressive symptoms in adolescent populations through interferences with problem-focused coping and other emotional regulation behaviors. Preventive programs could target coping interferences to improve public health. We discuss psychological models of why screen time may interfere with coping, including displacement effects and echo chamber phenomena.

25 January 2025 in Journal of Adolescence
Verified
Journal Article
Open access
TLTheresa Lemke
Theresa Lemke
SHSebastian Hökby
Sebastian Hökby
VCVladimir Carli
Vladimir Carli
GHGergö Hadlaczky
Gergö Hadlaczky
Introduction: Inadequate sleep duration and sleep‐related problems are highly prevalent among adolescents and pose a significant health risk during a critical development stage. This study seeks to explore associations between sleep and suicidal ideation among adolescents.Methods: Cross‐sectional questionnaire data from the baseline wave (2016‐2018) of a cohort of 12‐ to 16‐year‐old Swedish adolescents (n = 4433, 50.39% girls) were analyzed. A split‐sample approach was used for exploratory analyses and model selection. Logistic regression was used to estimate the associations between suicidal ideation and self‐reported sleep parameters (weekday sleep duration, sleep quality), both adjusted and unadjusted for depression.Results: Adolescents with suicidal ideation slept on average 60 min less on weekdays and reported worse sleep quality compared to those without suicidal ideation. Suicidal ideation was significantly associated with weekday sleep duration (p = 0.0267) and self‐perceived sleep quality (p = 0.0003). Associations remained after controlling for depression.Conclusions: Sleep problems in adolescents are associated with suicidal ideation, beyond the effect of depression. Findings may have implications for screening and suicide prevention among clinical populations of adolescents, as well as for public health interventions aimed at promoting sleep and mental health in adolescents.

12 July 2023 in Nordic Journal of Psychiatry
Verified
Journal Article
Closed access
HOHögni Oskarsson
Högni Oskarsson
LMLars Mehlum
Lars Mehlum
DTDavid Titelman
David Titelman
EIErkki Isometsä
Erkki Isometsä
AEAnnette Erlangsen
Annette Erlangsen
SPSigurdur Páll Palsson
Sigurdur Páll Palsson
Overall, suicide rates in the Nordic region, Denmark, Finland, Iceland, Norway and Sweden, have declined in the past 40 years. The aim of this study was to determine trends in suicide mortality from 2000 to 2018. Data were obtained from official suicide statistics for men and women, 15 years and older. Gender and age groups in four calendar periods were analyzed using Joinpoint Estimated Regression Coefficient. The crude regional suicide rate was 17.1, 2000-2004, decreased to 14.1 per 100,000 inhabitants in 2015-2018. Age-standardized rates are 13.6-11.3. The crude rate decreased by 19.5% (16.3% age-standardized), 19.3% for males and 20.5% for females. The largest decrease was found in Finland (34.9%), the smallest in Norway (1.4%). In males, the exception was an increased suicide rate among all Icelandic except 15-24-year olds, and in 45-64 year-old Norwegians. Among females, an increase was seen among 15-24-year olds in all countries except Iceland, in all age groups in Norway, and in 25-44-year olds in Sweden. In males, a decline of the suicide rated lower than 10% was noted in 25-44 olds in Norway and in 15-64 year-olds in Sweden. A robust decrease was observed in the overall regional suicide rate in recent years. Exceptions are rising rates in Icelandic males, in Norwegian females, and the youngest female groups in all except Iceland. The small decline among middle-aged males in Norway and Sweden is of concern.