On the environmental genetics of depressive symptoms : Focus on two serotonergic genes

Depression is a complex psychiatric disorder influenced by several genes, environmental factors, and their interplay. Serotonin receptor 2A (HTR2A) and tryptophan hydroxylase 1 (TPH1) genes have been implicated in vulnerability to depression and other psychiatric disorders, but the results have been inconsistent. The present study examined whether these two genes moderated the influence of different depressogenic environmental factors on subthreshold depressive symptoms (assessed on a modified version of Beck s Depression Inventory, BDI) and depression-related temperament, i.e., harm avoidance (assessed on the Temperament and Character Inventory, TCI). The environmental factors included measures of childhood and adolescence exposure, i.e., maternal nurturance and parental socioeconomic status, and adulthood social circumstances, i.e., perceived social support and urban/rural residence. The participants were two randomly selected subsamples (n = 1246, n = 341) from the longitudinal population-based Cardiovascular Risk in Young Finns study (n = 3596). Childhood environmental factors were assessed when the participants were 3 to 18 years of age, and three years after the baseline. Adulthood environmental factors and outcome measures were assessed 17 and 21 years later when the participants were 21 to 39 years of age. The T102C polymorphism of the HTR2A gene moderated the association between childhood maternal nurturance and adulthood depressive symptoms, such that exposure to high maternal nurturance predicted low depressive symptoms among individuals carrying the T/T or T/C genotypes, but not among those carrying the C/C genotype. Likewise, high parental SES predicted low adulthood harm avoidance in individuals carrying the T/T or T/C genotype, but not in C/C-genotype carriers. Individuals carrying the T/T or T/C genotype were also sensitive to urban/rural residence, such that they had lower depressive symptoms in urban than in rural areas, whereas those carrying the C/C genotype were not sensitive to urban/rural residence difference. HTR2A did not moderate the influence of social support. TheA779C/A218C haplotype of the TPH1 gene was not involved in the association between childhood environment and adulthood outcomes. However, individuals carrying A alleles of the TPH1 haplotype were more vulnerable to the lack of adulthood social support in terms of high depressive symptoms than their counterparts carrying no A alleles. Furthermore, individuals living in remote rural areas and carrying the A/A haplotype had higher depressive symptoms than those carrying other genotypes of the TPH1. The findings suggest that the HTR2A and TPH1 genes may be involved in the development of depression by influencing individual s sensitivity to depressogenic environmental influences.

Child temperament and parental personality: continuity and transactional change

Studying the continuity and underlying mechanisms of temperament change from early childhood through adulthood is clinically and theoretically relevant. Knowledge of the continuity and change of temperament from infancy onwards, especially as perceived by both parents is, however, still scanty. Only in recent years have researchers become aware that personality, long considered as stable in adulthood, may also change. Further, studies that focus on the transactional change of child temperament and parental personality also seem to be lacking, as are studies focusing on transactions between child temperament and more transient parental characteristics, like parental stress. Therefore, this longitudinal study examined the degree of continuity of temperament over five years from the infant s age of six months to the child s age of five and a half years, as perceived by both biological parents, and also investigated the bidirectional effects between child temperament and parents personality traits and overall stress experienced during that time. First, moderate to high levels of continuity of temperament from infancy to middle childhood were shown, depicting the developmental links between affectively positive and well-adjusted temperament characteristics, and between characteristics of early and later negative affectivity. The continuity of temperament was quantitatively and qualitatively similar in both parents ratings. The findings also demonstrate that infant and childhood temperament characteristics cluster to form stable temperament types that resemble personality types shown in child and adult personality studies. Second, the parental personality traits of extraversion and neuroticism were shown to be highly stable over five years, but evidence of change in relation to parents views of their child s temperament was also shown: an infant s higher positive affectivity predicted an increase in parental extraversion, while the infant s higher activity level predicted a decrease in parental neuroticism over five years. Furthermore, initially higher parental extraversion predicted higher ratings of the child s effortful control, while initially higher parental neuroticism predicted the child s higher negative affectivity. In terms of changes in parental stress, the infant s higher activity level predicted a decrease in maternal overall stress, while initially higher maternal stress predicted a higher level of child negative affectivity in middle childhood. Together, the results demonstrate that the mother- and father-rated temperament of the child shows continuity during the early years of life, but also support the view that the development of these characteristics is sensitive to important contextual factors such as parental personality and overall stress. While parental personality and experienced stress were shown to have an effect on the child s developing temperament, the reverse was also true: the parents own personality traits and perceived stress seemed to be highly stable, but also susceptible to their experiences of their child s temperament.

Perhetaustan ja sukupuolen yhteys koulunkäyntiin

Finnish education policy has aimed at providing equal educational pathways that level educational opportunities and aims at the equity of participation. Combined with the Finnish welfare state it has succeeded in sustaining social mobility. Yet the adolescents do not necessarily have equal possibilities to achieve these educational positions. Socio-economic differences in Finland are persistent and both education and poverty are still partly inherited. This thesis concentrated on prevailing socio-economic differences on school attendance and on studying the associations between family backgrounds, gender and school attendance. The key question for this thesis was formulated as: What kind of differences in school attendance there can be found among 9th graders from Helsinki according to their family background and their gender? The core data was a school-based survey carried on in Helsinki in 2004. There were two thirds of the schools of Helsinki and 2381 respondents. The questionnaire included questions on young people s school-related experiences, school attendance, school performance and their family. The analysis had three steps: after describing the respondents the associations between school attendance and family background were analyzed using MCA (Multiple Classification Analysis). Finally the associations between school attendance, family and school environment were studied using logistic regression analysis. The results showed that schooling (school attendance) was a variety of attitudes and experiences. The analysis showed also that all the family background factors had an effect on school attendance. From the family background measurements, it seems that the perceived parental support varied most with school attendance. Apart from the school environment factors, each family-related factor is statistically significantly related to two or more school attendance factors, even when adjusted with the school environment factors. There was also a gender-related difference in school attendance. Girls seem to like school attendance more than boys; they do better at school, but are also more worried about school work. Especially the expected associations with the parental educational level, but also with perceived parental support, gender and school attendance, are important results. When they are combined with the support pupils get from firm family structure and employment status it is possible to point out some factors that are relevant when discussing the ways educational achievements are moved to next generations in good and worse.

Rakkaat vanhemmat? : Perheen merkityksestä erityisluokan oppilaalle

The aim of this study was to find out the meaning family has for a pupil who studies in a special class, or how important family is for the pupil s emotional life, the development of his self-confidence, freetime activities, attitudes on school, plans for further studies and his general social development. The theoretical base of this study was formed by social scientists' theories on postmodern family, which is due to urbanization and urban life style, and theories on family pluralism, the powerful effects that changes in family life have on pupils in special education, the weak self-confidence and low sosioeconomic background among those pupils and the effects of family's sosioeconomic status on pupil's willingness to get education or the theory on the accumulation of education. Study problems were set in the direction determined by these theories and in order to study the accurateness of the theories. The method used in the study was theme interview, which is sometimes also called half-structured interview. The material for the study was collected in October 1998 in a special school in Helsinki. The material contains answers given by pupils in theme interviews and background information about pupils' families, which where collected from the pupils' parents by mail. Content analysis was used to analyze the material. The study showed that it is very important to pupils' attitudes on school and their self-confidence that their families are entire and that the families give them support. The children, whose parents are interested in school education and discuss a lot about things, seem to have positive attitudes on school and good self-confidence, too. The parental support also has an effect on how the pupils spend their free time and on their hobbies, too. Obviously the families have quite an important meaning for pupils in special class, but if the families don t support them, the consequence is problems particularly for the development of self-confidence. The theory on the low sosioeconomic background among students in special education gets support from this study, but nothing can be said about it's effect on further studies. On account of the results it can be suggested that special schools must arrange occasions where the pupils' parents are clearly informed about the important meaning of their support for the pupils studies and the development of the pupils' self-confidence. The most important sources for the theoretical background were the books written by Jallinoja, Kivinenand Rinne, Moberg, Scanzoni and P. Takala. The most important sources for the method were the books written by Hirsjärvi and Hurme and Pietilä. Keywords: family, special class, pupil in special education, support, self-confidence, postmodern family

Oral Health among Iranian Preadolescents : A School-Based Health Education Intervention

The present study assessed oral health and its determinants among Iranian preadolescents, and evaluated a school-based health education programme aimed to promote their oral health. The target population of this study comprised a random sample of the third-grade school children (n = 459) of all public primary schools in 19 areas of Tehran city. The data came from a clinical examination of the children and two self-administered questionnaires: one for children, and one for mothers. The clinical dental examination was performed for recording children's oral health. The mothers' questionnaires covered background factors, oral self-care (OSC) behaviours and oral health-related knowledge and attitude statements. After baseline data collection, a community trial was designed as a 3-month school-based intervention study. For the intervention trial, the third-grade classes as the clusters were randomly assigned to the intervention and control groups. Three kinds of intervention were implemented, one in class, one via the parents, and one as a combination of these. One group served as controls with no intervention. The outcome measures of the study were changes in plaque and bleeding scores recorded. The results showed that mean dmft was 3.75 (SD = 2.8) for the primary teeth and mean DMFT was 0.4 (SD = 0.9) for the permanent teeth. All children had plaque on at least one index tooth and bleeding on probing in at least one index tooth occurred in 81%. About one-third (34%) of the children reported favourable OSC and less than half (46%) of the children reported brushing their teeth at least twice daily. Girls reported favourable OSC (OR = 2.0), had decay-free teeth (OR = 1.8) and treated permanent teeth (OR = 3.3) more than did boys. Mother's oral health-related aspects, i.e., mother's favourable OSC, high knowledge levels of and positive attitudes towards oral health, and active supervision of the child's tooth brushing had a positive effect on all aspects of children's oral health status and behaviours (ORs from 1.3 to 1.9). After the intervention, the results showed a strong intervention effect on healthy gingiva in both groups where parents were involved: the parental-aid group (OR = 7.7, 95% CI 2.2-27.7) and combined group (OR = 6.6, 95% CI 2.0-22.1). To improve children's oral health, community school-based oral health educational programmes should be established to include all primary schools. These programmes should benefit from the common risk factor approach and a multi-sectored approach to employ for communication between the community, the school, and the family. Oral health interventions should empower the parents' ability to improve their own oral health behaviour and then to transfer that healthy behaviour to their children.

Smoking from Adolescence to Adulthood : A 15-year Follow-up of the North Karelia Youth Project

The aim of the study was to examine the effects of a smoking prevention program and smoking from early adolescence to early adulthood by using longitudinal data. In addition, predictors of smoking, smoking cessation, and associations of smoking with socio-economic factors and other health behaviours were assessed. The data was gathered in connection with the North Karelia Youth Project follow-up study during 15 years. A two-year cardiovascular disease risk factor prevention program was carried out among students from grades seven to nine in four schools in North Karelia. Two schools were selected from Kuopio province for the control schools. The North Karelia Project, a community-based cardiovascular disease prevention program, was implemented in the same area. At the baseline in 1978 the subjects were 13-year-olds (n=903) and in the following surveys 15-, 16-, 17-, 21- and 28-year-olds. The parents of the subjects were studied twice, in 1978 and 1980. A two-year intervention based on social influence approach prevented the onset of smoking for several years. The continuity of smoking from adolescence to adulthood was strong: most adolescent smokers were still smoking in adulthood. Moreover, approximately half of the 28-year-old smokers had started smoking after the age of 15. Previous smoking status and smoking by friends were the most important predictors of smoking. One third of all adolescent smokers had stopped smoking before the age of 28, averaging at 2.3 % annual decline. The socioeconomic status of the subject and, especially, education were strongly related to smoking, the lower socioeconomic groups smoking the most. Parental socioeconomic status and intergenerational social mobility were not significantly related to the smoking of the subject in adolescence or adulthood. Smoking was associated positively with the use of alcohol and negatively with physical activity from adolescence to adulthood. The results support the feasibility of a school-based social influence program with a community-based program in smoking prevention among adolescents. Strong continuity of smoking from adolescence to adulthood supports the importance of preventing the onset of smoking in adolescence. It would be useful to continue prevention programs also after the comprehensive school, since so many young start smoking after that. It would likewise be important to develop cessation programs tailor-made for adolescents and young adults. Additionally, the results support the importance of using methods based on social influence in smoking prevention and cessation programs, targeting especially such risk groups as those with low socioeconomic status as well as those with other unhealthy behaviours.

Socioeconomic Status, Occupational Factors and Lifestyle as Predictors of Hospitalisation for Back Disorders

The aim of this dissertation was to examine the determinants of severe back disorders leading to hospital admission in Finland. First, back-related hospitalisations were considered from the perspective of socioeconomic status, occupation, and industry. Secondly, the significance of psychosocial factors at work, sleep disturbances, and such lifestyle factors as smoking and overweight was studied as predictors of hospitalisation due to back disorders. Two sets of data were used: 1) the population-based data comprised all occupationally active Finns aged 25-64, and included hospitalisations due to back disorders in 1996 and 2) a cohort of employees followed up from 1973 to 2000 having been hospitalised due to back disorders. The results of the population-based study showed that people in physically strenuous industries and occupations, such as agriculture and manufacturing, were at an increased risk of being hospitalised for back disorders. The lowest hospitalisation rates were found in sedentary occupations. Occupational class and the level of formal education were independently associated with hospitalisation for back disorders. This stratification was fairly consistent across age-groups and genders. Men had a slightly higher risk of becoming hospitalised compared with women, and the risk increased with age among both genders. The results of the prospective cohort study showed that psychosocial factors at work such as low job control and low supervisor support predicted subsequent hospitalisation for back disorders even when adjustments were made for occupational class and physical workload history. However, psychosocial factors did not predict hospital admissions due to intervertebral disc disorders; only admissions due to other back disorders. Smoking and overweight predicted, instead, only hospitalisation for intervertebral disc disorders. These results suggest that the etiological factors of disc disorders and other back disorders differ from each other. The study concerning the association of sleep disturbances and other distress symptoms with hospitalisation for back disorders revealed that sleep disturbances predicted subsequent hospitalisation for all back disorders after adjustment for chronic back disorders and recurrent back symptoms at baseline, as well as for work-related load and lifestyle factors. Other distress symptoms were not predictive of hospitalisation.

Early growth and adult health: focus on blood pressure, glucose tolerance status and body composition

Theory of developmental origins of adult health and disease proposes that experiences during critical periods of early development may have consequences on health throughout a lifespan. Thesis studies aimed to characterize associations between early growth and some components of the metabolic syndrome cluster. Participants belong to two epidemiological cohorts with data on birth measurements and, for the younger cohort, on serial recordings of weight and height during childhood. They were born as singletons between 1924-33 and 1934-44 in the Helsinki University Central Hospital, and 500 and 2003 of them, respectively, attended clinical studies at the age of 65-75 and 56-70 years, respectively. In the 65-75 year old men and women, the well-known inverse relationship between birth weight and systolic blood pressure (SBP) was confined to people who had established hypertension. Among them a 1-kg increase in birth weight was associated with a 6.4-mmHg (95% CI: 1.0 to 11.9) decrease in SBP. This relationship was further confined to people with the prevailing Pro12Pro polymorphism of the peroxisome proliferator-activated receptor-γ2 (PPARγ2) gene. People with low birth weight were more likely to receive angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEI/ARB, p=0.03), and, again, this relationship was confined to the carriers of the Pro12Pro (p=0.01 for interaction). These results suggest that the inverse association between birth weight and systolic BP becomes focused in hypertensive people because pathological features of BP regulation, associated with slow fetal growth, become self-perpetuating in adult life. Insulin resistance of the Pro12Pro carriers with low birth weight may interact with the renin-angiotensin system leading to raised BP levels. Habitual physical activity protected men and women who were small at birth, and thus at increased risk for the development of type 2 diabetes, against glucose intolerance more strongly. Among subjects with birth weight ≤3000 g, the odds ratio (OR) for glucose intolerance was 5.2 (95% CI: 2.1 to 13) in those who exercised less than 3 times per week compared to regular exercisers; in those who scored their exercise light compared with moderate exercisers (defined as comparable to brisk walking) the OR was 3.5 (1.5 to 8.2). In the 56-70 year old men a 1 kg increase in birth weight corresponded to a 4.1 kg (95% CI: 3.1 to 5.1) and in women to a 2.9 kg (2.1 to 3.6) increase in adult lean mass. Rapid gain in body mass index (BMI), i.e. crossing from an original BMI percentile to a higher one, before the age of 2 years increased adult lean mass index (LMI, lean mass/height squared) without excess fat accumulation whereas rapid gain in BMI during later childhood, despite the concurrent rise in LMI, resulted in a relatively higher increase in adult body fat mass. These findings illustrate how genes, the environment and their interactions, early growth patterns, and adult lifestyle modify adult health risks which originate from early life.

Effects of living crown reduction on needle element status of Scots pine

A wide range of biotic and abiotic factors, operating over different time perspectives and intensities, cause defoliation and a rapid decrease in the crown size of trees. Scleroderris canker disease [Gremmeniella abietina (Lagerb.) Morelet] has caused widespread crown reduction and tree mortality in Scots pine (Pinus sylvestris L) in forests in Scandinavia during the last three decades. In the 1980's, attempts were made to show, on the basis of the higher foliar N and S concentrations of affected pines in the diseased area, that sulphur and nitrogen deposition predispose trees to G. abietina. Unfortunately, in many studies on defoliated trees, exceptionally high or low needle mineral nutrient concentrations are still often interpreted as one of the causes of tree injury and not, conversely, as the result. In this thesis, three different field experiments, with foliar analysis as the main study method, were conducted in order to asses the possible long-term effects of living crown reduction on the needle nutrient concentrations of Scots pine trees in southern Finland. The crown ratio and length of the living crown were used to estimate the amount of defoliation in the reduced canopies. The material for the partial studies was collected and a total of 968 foliar samples were analysed individually (15-17 elements/sample) on a total of 488 sample trees (140 diseased, 116 pruned and 232 control trees) during the years 1987-1996 in 13 Scots pine stands. All the three experiments of this thesis provided significant evidence that severe, disease-induced defoliation or artificial pruning of the living branches can induce long-lasting nutritional changes in the foliage of the recovering trees under the typical growing conditions for Scots pine. The foliar concentrations of all the 17 mineral nutrients/elements analysed were affected, to a varying degree, by artificial pruning during the following three years. Although Scots pine, as an evergreen conifer, is considered to have low induced chemical responses to defoliation, this study proved experimentally under natural forest conditions that severe artificial pruning or disease-induced defoliation of Scots pine trees may induce biologically significant changes in the concentrations of most of the important macro- and micronutrients, as well as of carbon, in refoliated needles. Concerning the studies in this thesis, I find the results significant in providing new information about the long-term effects of rapid living crown reduction on the foliar nutrient and element status of Scots pine trees. Key words: Foliar analysis, defoliation, needle loss, pruning, nutrients, Pinus sylvestris, Gremmeniella abietina