Background: Mental health problems (MHPs) have been seen to be associated with crime involvement among adolescents, especially externalising problems. Previous studies have often been made internationally and less research has been conducted within the Nordic countries, especially using self-reported data. Aims: To explore how differences in MHPs are associated with differences in crime involvement between adolescents, and how an individual’s change in mental health is associated with a change in crime involvement over time.

Methods: Data were drawn from the research project Malmö Individual and Neighborhood Development study (MINDS) and include 386 adolescents (53% girls; 47% boys). Longitudinal multilevel analysis was applied to assess the association between MHP and crime involvement.

Result: Overall, MHPs, particularly externalising problems, were associated with crime involvement. Also, changes in MHPs were related to changes in crime involvement over time. Fitting separate models for girls and boys yielded partly different results.

Conclusion: The results support previous findings that externalising problems are associated with crime involvement and show that an increase in externalising MHPs over time is associated with increased crime involvement. This underscores the importance of identifying and addressing externalising MHPs at an early stage to prevent a negative development.

BACKGROUND: Mental health problems (MHPs) are associated with youth offending, but research on MHPs among specifically offending girls, particularly in community settings, is limited.

AIMS: To explore if MHPs were more common among adolescent girls who reported committing crimes compared to those who did not, as well as to investigate how different MHPs were associated with offending, and examine the potential effects of parental relationships, parental monitoring, and association with deviant peers.

METHODS: Data were drawn from the Malmö Individual and Neighbourhood Development Study (MINDS), a longitudinal study which comprises a random sample of 525 adolescents (~ 20%) born in 1995 and living in Malmö, Sweden, in 2007. The current study included the 240 girls that participated in wave two (age 16) and three (age 17) of data collection. Data were collected using a self-reported questionnaire. Independent samples T-tests analysed differences in MHPs between offending and non-offending girls. Pearson's correlation test and logistic regressions examined the association between MHPs and offending and how these associations were affected by parental relationship, parental monitoring, and deviant peers.

RESULTS: Offending girls had higher levels of MHPs than non-offending girls, with the most significant differences in hyperactivity and externalising problems. Logistic regressions partly confirmed these findings, showing strong associations between externalising problems and offending. Internalising problems showed mixed results in their association with offending.

CONCLUSION: Girls who had offended had higher levels of both internalising and externalising MHPs compared to those who had not offended. This indicates that measures to prevent youth crime should acknowledge MHPs. Overall, more research is needed on girls' MHPs and offending, particularly on the association between internalising problems and offending.