1 Huikko E, et al. BMJ Open 2023;13:e065593. doi:10.1136/bmjopen-2022-065593 Open access Lifelong mental health service use among 15–22 years old offenders: a document-based, mixed-methods descriptive study Eeva Huikko , 1 Terhi Aalto-Setälä, 1 Päivi Santalahti, 1,2 Riikka Lämsä, 1,3 Aulikki Ahlgrén-Rimpiläinen 4 To cite: Huikko E, Aalto- Setälä T, Santalahti P, et al. Lifelong mental health service use among 15–22 years old offenders: a document- based, mixed-methods descriptive study. BMJ Open 2023;13:e065593. doi:10.1136/ bmjopen-2022-065593 ► Prepublication history and additional supplemental material for this paper are available online. To view these files, please visit the journal online (http://dx.doi.org/10.1136/ bmjopen-2022-065593). RL and AA-R are joint senior authors. Received 13 June 2022 Accepted 20 February 2023 1 Mental Health, Finnish Institute for Health and Welfare, Helsinki, Finland 2 Child Psychiatry, University of Turku, Turku, Finland 3 Public health, University of Helsinki, Helsinki, Finland 4 Forensic Psychiatry, Finnish Institute for Health and Welfare, Helsinki, Finland Correspondence to Dr Eeva Huikko; eeva.huikko@thl.fi Original research © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. ABSTRACT Objectives Among young offenders, psychiatric morbidity and comorbidity are common, but our knowledge about their use of mental health services during childhood and adolescence is scarce. We aimed to describe the lifelong use of mental health services of young offenders who have committed serious crimes. Design and study setting Using data on forensic psychiatric examinations of 42 Finnish offenders aged 15–22 years, we analysed the timing and typical patterns of their prior mental health service use with qualitative and quantitative content analysis and typification. Results Young offenders appeared in this study as children with plenty of perinatal and developmental risks, and risks related to their family situation and peer relations. Most subjects were described as having had emotional or behavioural symptoms, or both, since childhood. Involvement in mental health services was rare before the age of 7 years but increased markedly after that, staying on the same level during adolescence. Five categories of mental health service users were identified: (1) continuing service use around a decade (14.3%), (2) one brief fixed treatment (11.9%), (3) involuntary use of services (31.0%), (4) evasive use of services (21.4%) and (5) no mental health service use (21.4%). Conclusions Young offenders had symptoms from early ages, but during childhood and adolescence, involvement in mental health services appeared for most as relatively short, repetitive or lacking. To help children at risk of criminal development, a multiprofessional approach, an early evidence-based intervention for behavioural symptoms and screening for learning problems, traumatic experiences and substance use are necessary. Results can help identify children and adolescents with a risk of criminal development, to develop mental health services and to plan further research. INTRODUCTION Among young offenders, psychiatric morbidity and comorbidity are common 1 and can be long-lasting. 2 Factors contributing to the emergence of violent offences have been extensively studied. The association between criminality and adverse childhood experiences and living conditions is well documented. 3–8 Williams and colleagues 9 have reported traumatic brain injury to be a risk factor for early and violent crime. Also, childhood conduct disorders and neuro- psychiatric disorders have been shown to associate with serious crimes later in life, as well as during adolescence anxiety, hostility and borderline, paranoid and psychotic features. 10–15 As for diagnostic evaluations, the most common disorders among young offenders with serious crimes are conduct and personality disorders, 1 13 16–18 followed by affective and anxiety disorders as well as substance use disorders. 13 16–20 Despite the clear association between early criminality and mental health problems, our knowledge about the use of mental health services of young offenders during their childhood and adolescence is scarce. Of 5823 incarcerated Canadian youth, aged 12–24 years, who had mental health treatment during incarceration, 65% had used mental health services during the 5 years before incarceration. 21 In the USA, 36% of 423 first-time offenders, aged 12–18 years, had used psychiatric services during the 4 months before their offence. 22 The proportion of life- long use of specialist mental health services was 46% among 54 incarcerated adoles- cent females in the USA 19 and 40% among 270 incarcerated Swedish violent men aged 18–25 years. 13 Of 57 Finnish minors assessed STRENGTHS AND LIMITATIONS OF THIS STUDY ⇒ As a major strength, we consider our comprehen- sive data covering multiple informants. ⇒ Additionally, the use of mixed methods in analyses enables us to create a comprehensive and versatile picture of the research topic. ⇒ Convenience sample and qualitative study design limit the generalisability of the results.