Bullying at 8 years and violent offenses by 31 years: the Finnish nationwide 1981 birth cohort study.

This study explored the associations between bullying perpetration and victimization at 8 years of age and violent offenses by the age of 31. Data were obtained for subjects enrolled in a population-based longitudinal birth cohort study. In 1989, 5813 8-year-old children (attrition 3.4%), and their parents and teachers, were surveyed about bullying. When 5405 subjects (attrition 10.2%) were 15-31 years of age, violent offenses were extracted from the Finnish National Police Register. We analyzed the data by sex and categorized bullying perpetration and victimization by frequency. Violent offenses were categorized by severity. Cox regression analyses estimated the hazard ratios (HRs) and 95% confidence intervals (95% CIs). When they were compared to males who had not been bullies at 8 years of age, frequent male bullies had an increased hazard for violent offenses (adjusted HR 3.01, 95% CI 2.11-4.33) and severe violent offenses (adjusted HR 2.86, 95% CI 1.07-7.59) as adults, even when the data were controlled for them being victims, parental education level, family structure and child psychopathology. Frequent female bullies also had an increased hazard for violent offenses, compared to those who had not bullied others (adjusted HR 5.27, 95% CI 1.51-18.40). Frequent male bullying was associated with higher odds for violent offenses compared to only bullying sometimes. Being a victim was not associated with violent offenses. Preventing childhood bullying could reduce violent offenses by both sexes.

Incidence and comorbidities of disruptive behavior disorders diagnosed in Finnish specialist psychiatric services.

PURPOSE: Disruptive behavior disorders (DBD), including oppositional defiant disorder (ODD) and conduct disorder (CD), are some of the most common psychiatric conditions in childhood. Despite this, there has been limited research on DBDs. We examined the incidence, comorbidity and gender differences of DBDs diagnosed by specialist services. METHOD: This was a nationwide register study of 570,815 children and adolescents born in 1996-2005. The 7050 individuals diagnosed with DBD by specialist healthcare services were matched to 26,804 controls. RESULTS: By the age of 15, the cumulative incidence of diagnosed DBDs was 3.5% for boys and 1.4% for girls. The yearly incidence rate increased for girls after 13 years of age, while the incidence for boys was relatively stable between 8 and 15 years of age. When we compared subjects born between 1996-1998 and 1999-2001, we found that by the age of 12, the cumulative incidence per 100 people had increased from 0.56 to 0.68 among girls and from 2.3 to 2.6 among boys. This indicated a minor increase in treated incidence. The parents of children diagnosed with DBDs had lower educational levels than the parents of controls. Children with DBD were also more likely to have been diagnosed with other psychiatric disorders. CONCLUSION: Although DBDs were 3.5 times more common among boys during the whole follow-up period, the yearly incidence during adolescence was fairly similar between boys and girls. DBD existed alongside various psychiatric disorders at a relatively young age and only a minor increase in treated incidence was found during childhood.

Parental psychopathology and offspring attention-deficit/hyperactivity disorder in a nationwide sample.

OBJECTIVE: To study the associations between a wide range of parental psychiatric disorders and offspring attention-deficit/hyperactivity disorder (ADHD). METHOD: This study is based on a nested case-control design. The association between parental registered psychiatric diagnoses and offspring ADHD was examined adjusting for socioeconomic and prenatal factors. Data was linked from Finnish nationwide registers. The cases (n = 10,409) were all the children born between years 1991 and 2005 in Finland and diagnosed with ADHD by the end of 2011. Four controls without ADHD (n = 39,124) were matched for every case by sex, age and place of birth. Main outcomes were adjusted odds ratio (aOR) for parental diagnosis of cases vs controls. Analyses were further stratified by sex. Disorders diagnosed before and after birth were analyzed separately. RESULTS: The odds ratio for ADHD increased when only mother (aOR 2.2, 95% CI 2.0-2.3), only father (aOR 1.7, 95% CI 1.6-1.8) and both parents (aOR 3.6, 95% CI 3.3-4.0) were diagnosed. Maternal diagnosis showed stronger association than paternal. The weight of association between several parental disorders and offspring ADHD were similar. Maternal psychopathology overall showed stronger associations with girls than boys with ADHD. The diagnoses registered after birth did not show stronger association than the diagnoses registered before. CONCLUSIONS: Maternal psychopathology showing stronger association than paternal implies that environmental factors or their interaction with genetic factors partly mediates the risk of parental psychopathology. Similar associations between several maternal psychiatric disorders and offspring ADHD points towards the need for investigating some common mother-related risk factors.