The aims of this study were to examine the prevalence, co-occurrence, and psychosocial determinants of self-perceived headache, abdominal pain, and sleep problems among adolescents. The adolescents from two cities in Finland (n = 2,215, 90.9% of the target population) attending 7th and 9th grade (age range 13-18 years) participated in the cross-sectional survey inquiring about frequency of headache, abdominal pain, sleep problems, and psychosocial difficulties. The 6-month prevalence of weekly headache was 13%, abdominal pain 6%, and sleep problems 27%. All three symptoms were strongly associated with each other. Of the adolescents suffering from one symptom, 32% reported one co-occurring symptom and 17% two co-occurring symptoms. In the multivariate analysis, female gender, experience of psychological difficulties, emotional symptoms, smoking, victimization, and feeling not cared about by teachers were independently associated with all the individual symptoms, as well as an increasing number of symptoms. Sleep problems were associated with older age and peer and alcohol problems. Abdominal pain was associated with conduct problems, and both headache and abdominal pain were linked with immigration background. An increasing number of symptoms was associated with older age, having a chronic illness, and conduct and alcohol problems. Adolescents' headache, abdominal pain and sleep problems were common and often co-occurred. An increasing frequency of each symptom and number of symptoms were associated with psychosocial factors in a similar way. Screening for psychiatric symptoms, substance use, victimization and difficulties with teachers should be included in the assessment of adolescents who suffer from recurrent headache, abdominal pain or sleep problems.

The present study examines the 10-year time-trend changes of adolescent psychiatric symptoms, smoking and alcohol use. Representative population-based samples with same methods at two time-points, same age range and with 10-year period between the time points were gathered in Finland to investigate secular changes in adolescents' emotional and behavioral problems. Seventh and ninth grade students filled in the Strengths and Difficulties Questionnaire (SDQ) and questions regarding alcohol use and smoking anonymously during a school lesson in 1998 (n = 1458) and 2008 (n = 1569). The self-reports of SDQ showed substantial stability in emotional and behavioral problems from 1998 to 2008. There was no increase between the two timepoints in self-reports of SDQ total, conduct, hyperactivity, emotional or peer problems when using the 90th percentile clinical cut-off points. However, there was a trend showing decreasing prosocial behavior among girls indicating that proportions of adolescent boys and girls having problems in prosocial behavior have converged, The self-reported alcohol use, drunkenness and cigarette smoking decreased within the 10-year time period. Of alcohol use, the number of non-users increased from 44 to 63 % between the years 1998 and 2008. Similarly, the proportion of non-smokers increased from 56 to 68 %. Although rates of substance use declined within the 10-year study period, drunkenness-oriented alcohol use and regular smoking are still prevalent among Finnish adolescents.

This article presents an overview of the Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A), a new study designed to examine the relationship between prenatal serologic factors, mediating and moderating developmental antecedents, and risk of autism spectrum disorders (ASD). The FIPS-A is based on register linkages between births from 1987 to 2005 ascertained from the Finnish Medical Birth Register (FMBR) and other national registers on treatment for this group of disorders. All subjects were members of the Finnish Maternity Cohort (FMC), which consists of virtually all births in Finland from 1983 to the present, and which includes archived maternal serum samples. This study also capitalizes on other registry information, such as systematically collected data on pregnancy, prenatal and neonatal complications and manual data collection from well-child clinics providing developmental data from birth to the age of 7 years. In this paper, we describe the methods used in the FIPS-A study, including a description of the national registers, available data and case ascertainment procedures. Finally, we discuss implications of the data for future work on uncovering putative aetiologies of ASD and key strengths and limitations of the design.

The study was supported by Autism Speaks, NIMH 1K02-MH65422 and NIEHS 1R01ES019004. There are no competing interests.