Plant water use related to leaf traits and CSR strategies of 10 common European green roof species

The vegetation layer contributes to multiple functions of green roofs including their hydrological function as plants remove water from substrates between rainfall events through evapotranspiration, restoring the green roofs storage capacity for rainfall retention. While individual traits have been related to water use strategies of green roof plants, these traits are inconsistent, suggesting the importance of trait combinations which may be reflected in CSR (competitor, stress tolerator, ruderal) strategies. Therefore, relating plant water use to leaf traits and CSR strategies could help facilitate green roof plant selection into new geographical regions where green roof technology is developing. For example, in high latitude northern European regions with long daylight during the growing season. Growth (shoot biomass, relative growth rate and leaf area), leaf traits (leaf dry matter content, specific leaf area and succulence) and CSR strategies were determined of 10 common European green roof plants and related to their water use under well-watered (WW) and water-deficit (WD) conditions. All three succulent species included in the experiment showed mostly stress tolerant traits and their water loss was less than the bare unplanted substrate, likely due to mulching of the substrate surface. Plants with greater water use under WW conditions had more ruderal and competitive strategies, and greater leaf area and shoot biomass, than species with lower WW water use. However, the four species with the highest water use under WW conditions were able to downregulate their water use under WD, indicating that they could both retain rainfall and survive periods of water limitations. This study indicates that, for optimal stormwater retention, green roof plant selection in high latitude regions like northern Europe, should focus on selecting non-succulent plants with predominantly competitive or ruderal strategies to make the most of the long daylight during the short growing season.

Temperatures and precipitation affect vegetation dynamics on Scandinavian extensive green roofs

Standard succulent vegetation mixes developed mostly in temperate climates are being increasingly used on green roofs in different climate zones with uncertain outcome regarding vegetation survival and cover. We investigated vegetation on green roofs at nine temperate, cold, and/or wet locations in Norway and Sweden covering wide ranges of latitude, mean annual temperature, annual precipitation, frequencies of freeze-thaw cycles, and longest annual dry period. The vegetation on the roofs were surveyed in two consecutive years, and weather data were compiled from meteorological databases. At all sites we detected a significant decline in species compared to originally intended (planted/sown) species. Both the survival rate and cover of the intended vegetation were positively related to the mean annual temperature. Contrary to a hypothesis, we found that intended vegetation cover was negatively rather than positively related to mean annual precipitation. Conversely, the unintended (spontaneous) vegetation was favoured by high mean annual precipitation and low mean annual temperature, possibly by enabling it to colonize bare patches and outcompete the intended vegetation. When there is high mortality and variation in cover of the intended vegetation, predicting the strength of ecosystem services the vegetation provides on green roofs is difficult. The results highlight the needs for further investigation on species traits and the local factors driving extinction and colonizations in order to improve survivability and ensure a dense vegetation throughout the successional stages of a green roof.

Vegetation cover and plant diversity on cold climate green roofs

Both vegetation abundance and community composition play important roles in functions of green roofs (e.g. stormwater retention, habitat provision, aesthetic appearance). However, green roofs’ vegetation, and hence their functions, can change significantly over time. More understanding of these changes is required, particularly in cold climates. Therefore, this study investigated vascular plant covers and species compositions on 41 roof sections located in Sweden’s subarctic and continental climate zones. For the roof sections with a known originally intended vascular plant composition (n = 32), on average 24 ± 9% of the intended species were detected in surveys, and unintended species accounted for 69 ± 3% of the species found. However, most colonizing species formed sparse cover on the roofs. Thus, they may make less contributions to green roofs’ potential functionalities related to vegetation density (e.g. social perception, effectiveness in stormwater management and thermal performance) than the intended vegetation. The intended species dominated plant cover (93 ± 3%) and Sedum acre (58 ± 36% cover) was the most commonly detected species and as found in previous studies, substrate depth was positively related to both plant cover and species richness. Contrary to a hypothesis, the roofs’ vascular plant cover was not related to species richness but was significantly and negatively correlated with moss cover. The results highlight the importance of substrate depth for both plant abundance and species diversity and show that even in a cold climate, colonizing unintended species can strongly contribute to green roofs’ species richness.

Accuracy of register-based schizophrenia diagnoses in a genetic study

In order to assess the accuracy of schizophrenia diagnoses for genetic studies, we identified all schizophrenia patients (n = 492) in an isolated community with a diagnosis of schizophrenia in the Finnish Hospital Discharge Register (HDR) between 1969-1991. For the accuracy study we identified a sample of 73 patients from registers with Diagnostic and Statistical Manual (DSM)-III-R for schizophrenia (codes 295.10, 295.30, 295.60, 295.90) (n = 62) or “schizophrenia spectrum” diagnoses (295.40, 295.70, 297.10, 301.20, 301.22) (n = 11). When the operational criteria (DSM-III-R) were applied by two senior researchers using information from the original mental hospital records, 93% (68/73) of the cases fulfilled criteria for schizophrenia or schizophrenia spectrum. The results demonstrate that the schizophrenia diagnoses of the registers are accurate when a broad concept of schizophrenia is applied. When using operational DSM-III-R schizophrenia criteria, eight false positive cases were found among the 62 mental hospital schizophrenia diagnoses. Consequently, there may be a need to reassess schizophrenia diagnoses depending on the purpose of the study. We also found good agreement between DSM-III-R (kappa 0.93) and operational criteria (OPCRIT) diagnostic system (kappa 0.89) diagnoses, made by one researcher, compared with operational diagnoses. This indicates the possibility for the reliable use of one of these methods alone for diagnostic reassessment. The information in the HDR on primary diagnoses and on the dates of admission and discharge was accurately transferred from the hospital records.

Witchcraft, Religion and Suicides in the Light of the Witch Hammer and Contemporary Cases

The suicidal behavior of those accused of witchcraft five hundred years ago has its counterparts today. A comparison is made between case histories described in The Witch Hammer (1487), and contemporary clinical cases. The church's attitude toward suicide is examined, with particular attention given to the defense mechanism of projection. Although there are elements in religion which counteract suicidal impulses, the breakdown of a strictly religious mode of life can arouse intensive guilt feelings and aggravate the risk of self-destruction. Similarities in attitudes toward accused witches and psychiatric patients are noted and discussed.

Finnish Twins Reared Apart III: Personality Factors

This study is based on data from 165 adult twin pairs separated at 10 years or less. Information on personality factors: extraversion (E) and neuroticism (N) (EPI scale short from), life satisfaction (LS) (Allardt) and stress of daily activities (SDA) was obtained as part of the questionnaire study carried out in the entire Finnish Twin Cohort in 1975. Later in 1979 a questionnaire sent to the twins reared apart yielded a scale (range 7-30 points) measuring the environmental dissimilarities after separation (reliability 0.83). The effect of separation on personality factors by analysis of variance of individual data was studied. Sex, zygosity and age-at-separation were included in the models. The overall expalanatory rates were low (2.1-4.4%). The definitive study group was formed by selecting those pairs with a dissimilarity score greater than 15. The following intraclass correlations were obtained:

Both low birthweight and high birthweight are associated with cognitive impairment in persons with schizophrenia and their first-degree relatives

BACKGROUND

Both low birthweight and high birthweight have been associated with an increased risk for schizophrenia and cognitive impairments in the general population. We assessed the association between birthweight and cognitive performance in persons with schizophrenia and their unaffected first-degree relatives.

METHOD

We investigated a population-based family sample comprising persons with schizophrenia (n = 142) and their unaffected first-degree relatives (n = 277). Both patients and relatives were interviewed with the Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version (SCID-CV) and a comprehensive neuropsychological test battery was administered. Information on birthweight was obtained from obstetric records. We used generalized estimating equation (GEE) models to investigate the effect of birthweight, as a continuous variable, on cognitive functioning, adjusting for within-family correlation and relevant covariates.

RESULTS

Both low birthweight and high birthweight were associated with lower performance in visuospatial reasoning, processing speed, set-shifting and verbal and visual working memory among persons with schizophrenia and their unaffected first-degree relatives compared to individuals with birthweight in the intermediate range. The group × birthweight interactions were non-significant.

CONCLUSIONS

Both low birthweight and high birthweight are associated with deficits in cognition later in life. Schizophrenia does not seem to modify the relationship between birthweight and cognition in families with schizophrenia.

Activities of daily living, social functioning and their determinants in persons with psychotic disorder

OBJECTIVE

The determinants of everyday functioning in persons with psychotic disorder have not been widely studied in community dwelling samples. Our aim was to investigate limitations in everyday functioning among subjects with psychotic disorders in a population-based study.

METHOD

Everyday functioning was assessed in a nationally representative sample of 7112 persons aged 30+ using interviewer observations and self-reports, while verbal fluency and memory were also measured. Diagnostic assessment of DSM-IV psychotic disorders was based on SCID interview and case-note data. Lifetime-ever diagnoses of psychotic disorder were classified into schizophrenia (n=61), other non-affective psychotic disorders (ONAP) (n=79) and affective psychoses (n=45).

RESULT

Non-affective psychotic disorder was significantly associated with limitations in everyday functioning, as well as with deficits in verbal fluency and memory. Negative symptoms, depression, age, gender, verbal memory deficits, and reduced visual acuity were predictors of limitations in everyday functioning even after controlling for sociodemographic factors and chronic medical conditions, and difficulties in social functioning were also related to expressive speech problems.

CONCLUSION

Persons with schizophrenia and ONAP have significantly more problems in everyday functioning than the general population. One significant predictor of problems was reduced visual acuity, which at least in some situations could be easily corrected.

Cognitive functioning in a population-based sample of young adults with anxiety disorders

OBJECTIVE

Cognitive functioning in anxiety disorders has received little investigation, particularly among young adults and in non-clinical samples. The present study examined cognitive functioning in a population-based sample of young adults with anxiety disorders in comparison to healthy peers.

METHODS

A population-based sample of 21-35-year-olds with a lifetime history of anxiety disorders (n=75) and a random sample of healthy controls (n=71) derived from the same population were compared in terms of performance in neuropsychological tests measuring verbal and visual short-term memory, verbal long-term memory, attention, psychomotor processing speed, and executive functioning.

RESULTS

In general, young adults with anxiety disorders did not have major cognitive impairments when compared to healthy peers. When participants with anxiety disorder in remission were excluded, persons with current anxiety disorder scored lower in visual working memory tests. Current psychotropic medication use and low current psychosocial functioning associated with deficits in executive functioning, psychomotor processing speed, and visual short-term memory.

CONCLUSION

Lifetime history of anxiety disorders is not associated with cognitive impairment among young adults in the general population. However, among persons with anxiety disorders, current psychotropic medication use and low psychosocial functioning, indicating more severe symptoms, may associate with cognitive impairments.

Proton MRS in twin pairs discordant for schizophrenia

Proton magnetic resonance spectroscopy ((1)H MRS) neurometabolite abnormalities have been detected widely in subjects with and at risk for schizophrenia. We hypothesized that such abnormalities would be present both in patients with schizophrenia and in their unaffected twin siblings. We acquired magnetic resonance spectra (TR/TE=3000/30 ms) at voxels in the mesial prefrontal gray matter, left prefrontal white matter and left hippocampus in 14 twin pairs discordant for schizophrenia (2 monozygotic, 12 dizygotic), 13 healthy twin pairs (4 monozygotic, 9 dizygotic) and 1 additional unaffected co-twin of a schizophrenia proband. In the mesial prefrontal gray matter voxel, N-acetylaspartate (NAA), creatine+phosphocreatine (Cr), glycerophosphocholine+phosphocholine (Cho) and myo-inositol (mI) did not differ significantly between patients with schizophrenia, their unaffected co-twins or healthy controls. However, glutamate (Glu) was significantly lower in patients with schizophrenia (31%, percent difference) and unaffected co-twins (21%) than in healthy controls (collapsed across twin pairs). In the left hippocampus voxel, levels of NAA (23%), Cr (22%) and Cho (36%) were higher in schizophrenia patients compared with controls. Hippocampal NAA (25%), Cr (22%) and Cho (37%) were also significantly higher in patients than in their unaffected co-twins. Region-to-region differences in metabolite levels were also notable within all three diagnosis groups. These findings suggest that (1)H MRS neurometabolite abnormalities are present not only in patients with schizophrenia, but also in their unaffected co-twins. Thus, reduced mesial prefrontal cortical Glu and elevated hippocampal NAA, Cr and Cho may represent trait markers of schizophrenia risk and, when exacerbated, state markers of schizophrenia itself.

The effect of psychiatric co-morbidity on cognitive functioning in a population-based sample of depressed young adults

BACKGROUND

Psychiatric co-morbidity is often inadequately controlled for in studies on cognitive functioning in depression. Our recent study established no major deficits in cognition among young adults with a history of pure unipolar depression. The present study extends our previous work by examining the effects of psychiatric co-morbidity and other disorder characteristics on depression-related cognitive functioning.

METHOD

Performance in verbal and visual short-term memory, verbal long-term memory and learning, attention, processing speed, and executive functioning was compared between a population-based sample aged 21-35 years with a lifetime history of unipolar depressive disorders (n=126) and a random sample of healthy controls derived from the same population (n=71). Cognitive functioning was also compared between the subgroups of pure (n=69) and co-morbid (n=57) depression.

RESULTS

The subgroups of pure and co-morbid depression did not differ in any of the cognitive measures assessed. Only mildly compromised verbal learning was found among depressed young adults in total, but no other cognitive deficits occurred. Received treatment was associated with more impaired verbal memory and executive functioning, and younger age at first disorder onset with more impaired executive functioning.

CONCLUSIONS

Psychiatric co-morbidity may not aggravate cognitive functioning among depressed young adults. Regardless of co-morbidity, treatment seeking is associated with cognitive deficits, suggesting that these deficits relate to more distress.

DISC1 association, heterogeneity and interplay in schizophrenia and bipolar disorder

Disrupted in schizophrenia 1 (DISC1) has been associated with risk of schizophrenia, schizoaffective disorder, bipolar disorder, major depression, autism and Asperger syndrome, but apart from in the original translocation family, true causal variants have yet to be confirmed. Here we report a harmonized association study for DISC1 in European cohorts of schizophrenia and bipolar disorder. We identify regions of significant association, demonstrate allele frequency heterogeneity and provide preliminary evidence for modifying interplay between variants. Whereas no associations survived permutation analysis in the combined data set, significant corrected associations were observed for bipolar disorder at rs1538979 in the Finnish cohorts (uncorrected P=0.00020; corrected P=0.016; odds ratio=2.73+/-95% confidence interval (CI) 1.42-5.27) and at rs821577 in the London cohort (uncorrected P=0.00070; corrected P=0.040; odds ratio=1.64+/-95% CI 1.23-2.19). The rs821577 single nucleotide polymorphism (SNP) showed evidence for increased risk within the combined European cohorts (odds ratio=1.27+/-95% CI 1.07-1.51), even though significant corrected association was not detected (uncorrected P=0.0058; corrected P=0.28). After conditioning the European data set on the two risk alleles, reanalysis revealed a third significant SNP association (uncorrected P=0.00050; corrected P=0.025). This SNP showed evidence for interplay, either increasing or decreasing risk, dependent upon the presence or absence of rs1538979 or rs821577. These findings provide further support for the role of DISC1 in psychiatric illness and demonstrate the presence of locus heterogeneity, with the effect that clinically relevant genetic variants may go undetected by standard analysis of combined cohorts.

Body composition in psychotic disorders: a general population survey

BACKGROUND

The literature suggests an association between obesity and schizophrenia but fat mass and fat-free mass, which have been shown to be more predictive of all-cause mortality than only waist circumference and obesity [body mass index (BMI) 30 kg/m2], have not been reported in psychotic disorders. We examined the detailed body composition of people with different psychotic disorders in a large population-based sample.

METHOD

We used a nationally representative sample of 8082 adult Finns aged 30 years with measured anthropometrics (height, weight, waist circumference, fat percentage, fat-free mass and segmental muscle mass). Psychiatric diagnoses were based on a consensus procedure utilizing the Structured Clinical Interview for DSM-IV (SCID)-interview, case-notes and comprehensive register data.

RESULTS

Schizophrenia (including schizo-affective disorder) was associated with obesity [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.5-3.6], abdominal obesity (waist circumference 88 cm for women, 102 cm for men) (OR 2.2, 95% CI 1.3-3.6) and with higher fat percentage (mean difference 3.8%, 95% CI 2.0-5.7%), adjusted for age and gender, than in the remaining sample. The associations between schizophrenia and low fat-free mass and decreased muscle mass on trunk and upper limbs became statistically significant after adjusting for BMI. After further adjusting for current antipsychotic medication, education, diet and smoking, schizophrenia remained associated with obesity (OR 1.9, 95% CI 1.1-3.6) and abdominal obesity (OR 3.8, 95% CI 1.5-9.4). Participants with affective psychoses did not differ from the general population.

CONCLUSIONS

Individuals with schizophrenia have metabolically unfavorable body composition, comprising abdominal obesity, high fat percentage and low muscle mass. This leads to increased risk of metabolic and cardiovascular diseases.

Mental disorders in young adulthood

BACKGROUND

The effect of mental disorders may be particularly detrimental in early adulthood, and information on mental disorders and their correlates in this age group is important.

METHOD

A questionnaire focusing on mental health was sent to a nationally representative two-stage cluster sample of 1863 Finns aged 19 to 34 years. Based on a mental health screen, all screen-positives and a random sample of screen-negatives were asked to participate in a mental health assessment, consisting of the Structured Clinical Interview for DSM-IV (SCID-I) interview and neuropsychological assessment. We also obtained case-notes from all lifetime mental health treatments. This paper presents prevalences, sociodemographic associations and treatment contacts for current and lifetime mental disorders.

RESULTS

Forty percent of these young Finnish adults had at least one lifetime DSM-IV Axis I disorder, and 15% had a current disorder. The most common lifetime disorders were depressive disorders (17.7%) followed by substance abuse or dependence (14.2%) and anxiety disorders (12.6%). Of persons with any lifetime Axis I disorder, 59.2% had more than one disorder. Lower education and unemployment were strongly associated with current and lifetime disorders, particularly involving substance use. Although 58.3% of persons with a current Axis I disorder had received treatment at some point, only 24.2% had current treatment contact. However, 77.1% of persons with a current Axis I disorder who felt in need of treatment for mental health problems had current treatment contact.

CONCLUSIONS

Mental disorders in young adulthood are common and often co-morbid, and they may be particularly harmful for education and employment in this age group.

Mortality in offspring of mothers with psychotic disorder

BACKGROUND

Previous studies suggest that offspring of mothers with psychotic disorders have an almost two-fold higher mortality risk from birth until early adulthood. We investigated predictors of mortality from late adolescence until middle age in offspring of mothers with psychotic disorders.

METHOD

The Helsinki High-Risk Study follows up offspring (n=337) of women treated for schizophrenia spectrum disorders in mental hospitals in Helsinki before 1975. Factors related to mortality up to 2005 among offspring of these mothers was investigated with a survival model. Hazard rate ratios (HRR) were calculated using sex, diagnosis of psychotic disorder, childhood socio-economic status, maternal diagnosis, and maternal suicide attempts and aggressive symptoms as explanatory variables. The effect of family was investigated by including a frailty term in the model. We also compared mortality between the high-risk group and the Finnish general population.

RESULTS

Within the high-risk group, females had lower all-cause mortality (HRR 0.43, p=0.05) and mortality from unnatural causes (HRR 0.24, p=0.03) than males. Having themselves been diagnosed with a psychotic disorder was associated with higher mortality from unnatural causes (HRR 4.76, p=0.01), while maternal suicide attempts were associated with higher suicide mortality (HRR 8.64, p=0.03). Mortality in the high-risk group was over two-fold higher (HRR 2.44, p<0.0001) than in the general population, and remained significantly higher when high-risk offspring who later developed psychotic disorders were excluded from the study sample (HRR 2.30, p<0.0001).

CONCLUSIONS

Offspring of mothers with psychotic disorder are at increased risk of several adverse outcomes, including premature death.

Replication of linkage on chromosome 7q22 and association of the regional Reelin gene with working memory in schizophrenia families

Schizophrenia is a common and complex mental disorder. Hereditary factors are important for its etiology, but despite linkage signals reported to several chromosomal regions in different populations, final identification of predisposing genes has remained a challenge. Utilizing a large family-based schizophrenia study sample from Finland, we have identified several linked loci: 1q32.2-q42, 2q, 4q31, 5q and 7q22. In this study, an independent sample of 352 nuclear schizophrenia families (n=1626) allowed replication of linkage on 7q21-32. In a sample of 245 nuclear families (n=1074) originating from the same geographical region as the families revealing the linkage, SNP and microsatellite association analyses of the four regional candidate genes, GRM3, RELN, SEMA3A and VGF, revealed no significant association to the clinical diagnosis of schizophrenia. Instead, quantifiable trait component analyses with neuropsychological endophenotypes available from 186 nuclear families (n=861) of the sample showed significant association to RELN variants for traits related to verbal (P=0.000003) and visual working memory (P=0.002), memory (P=0.002) and executive functioning (P=0.002). Trait-associated allele-positive subjects scored lower in the tests measuring working memory (P=0.0004-0.0000000004), memory (P=0.02-0.0001) and executive functioning (P=0.001). Our findings suggest that allelic variants of RELN contribute to the endophenotypes of schizophrenia.

Costs of brain disorders in Finland

OBJECTIVE

To calculate the costs of brain disorders on the national level.

METHODS

Electronic data bases, national registers and internet data.

RESULTS

Any brain disorder was estimated to affect a fifth of the Finnish population. The three most common disorders were migraine, anxiety disorder and affective disorder. The total costs of brain disorders constituted 3% of the national gross product, or 45% of all the health-care costs. However, this is likely a conservative estimate, because not all chronic brain disorders and not all costs were included. Of the total costs of brain disorders, 32% were for direct health care, 23% for indirect medical care and 45% for indirect costs. Dementia was the most costly individual brain disorder followed by addiction and affective disorders. Most costly per case were brain tumours and multiple sclerosis.

CONCLUSION

Brain disorders constitute a costly part of the population's health costs. Directed preventive measures are needed to counteract the population morbidity and to control the increasing cost pressure in health care.

The factorial structure of the Suicide Intent Scale: a comparative study in clinical samples from 11 European regions

Although the Suicide Intent Scale (SIS) is a widely used instrument in research on suicidal behavior, comparative research on the latent structure of the SIS has been neglected. To determine whether a general factor model of the SIS is supported, alternative factor models of the SIS were evaluated comparatively in 11 clinical samples. The SIS was applied as part of a structured clinical interview to patients after an episode of non-fatal suicidal behavior. The samples were drawn from 11 study centers within the frame of the WHO/EURO multicenter study on suicidal behavior. Three different two-factor and two three-factor models of the SIS were examined in each sample using principal component analysis with orthogonal Procrustes rotation. The factorial structure of the 'subjective part' of the SIS (items 9-14) was strongly supported, whereas an acceptable model fit for the 'objective part' was not found. Possible future revisions of 'objective' SIS items may be worth consideration. As a limitation, the results of the study might not generalize to other samples that use different definitions of non-fatal suicidal behavior.

Growth pattern and risk of schizophrenia

BACKGROUND

Foetal nutrition and growth seem to affect the risk of developing schizophrenia. Exposure to famine during foetal development and low birthweight increase the risk. However, few studies have investigated the association between schizophrenia and adult height and weight or patterns of growth.

METHOD

The study population consisted of two subpopulations: families with at least one member with schizophrenia, and families of offspring of mothers with psychotic disorder, and controls. Using a seven-parameter model of height growth curves, we compared the parameters of persons who later developed schizophrenia and their unaffected siblings from the same families. We also studied how growth curve parameters differed in children with genetic risk for schizophrenia and controls, and whether weight, height and body mass index (BMI) at different ages predicted later development of schizophrenia.

RESULTS

The predicted growth curves based on a parametric model were nearly identical for persons with schizophrenia and their unaffected siblings. Adult height of daughters of mothers with psychoses was borderline significantly (p=0.0536) lower compared to controls, while no difference was detected among sons (p=0.3283).

CONCLUSIONS

No association between growth characteristics and schizophrenia in families with at least one member with schizophrenia was found. Family-related factors should be taken into account as possible confounders in future studies on growth and schizophrenia.

Incorporating serotypes into family based association studies using the MFG test

Family based association tests are widely used to detect genetic effects. The focus of this paper is the maternal-fetal genotype (MFG) incompatibility test, a family based association test which can be used to detect genetic effects that contribute to disease, including alleles in the child that increase disease risk, maternal alleles that increase disease risk in the child, and maternal-fetal genotype incompatibilities. Consideration of incomplete data resulting from using serotypes could expand the power of the MFG test for detecting genetic effects. Serotypes may be all that are available in certain families, or preferred because of convenience or low cost, and thus a modification of the MFG test will allow optimal use of such data. The modified MFG likelihood can accommodate the incomplete data that result from using serotypes rather than the corresponding codominant genotypes. The modified MFG test was evaluated with serotypes and genotypes from families with members affected with schizophrenia. In addition, simulation studies were performed. Results of the data analyses and simulation studies showed that serotypes can be used to augment genotypes within a sample, to increase power to detect effects when the candidate gene produces serotypes.

A haplotype within the DISC1 gene is associated with visual memory functions in families with a high density of schizophrenia

We have previously reported evidence of linkage and association between markers on 1q42 and schizophrenia in a study sample of 498 multiply affected Finnish nuclear families, leading to the recent identification of four significantly associated haplotypes that specifically implicate the Translin-Associated Factor X (TRAX) and Disrupted in Schizophrenia 1 and 2 (DISC1 and DISC2) genes in the genetic etiology of schizophrenia. Previously, the DISC genes were found to be disrupted by a balanced translocation (1;11)(q42.1;q14.3) that cosegregated with schizophrenia and related disorders in a large Scottish pedigree. Interestingly, we also reported earlier suggestive linkage between endophenotypic quantitative traits of visual and verbal memory and microsatellite markers in close proximity to TRAX/DISC, on 1q41. Here, we tested if the identified allelic haplotypes of TRAX/DISC would be associated with visual and/or verbal memory function impairments that are known to aggregate with schizophrenia in families. One haplotype of DISC1, HEP3, displayed association with poorer performance on tests assessing short-term visual memory and attention. Analysis of affected and unaffected offspring separately revealed that both samples contribute to the observed association to visual working memory. These results provide genetic support to the view that the DISC1 gene contributes to sensitivity to schizophrenia and associated disturbances and affects short-term visual memory functions. This finding should stimulate studies aiming at the molecular characterization of how the specific alleles of DISC1 affect the visual memory functions and eventually participates in the development of schizophrenia.

Replication of 1q42 linkage in Finnish schizophrenia pedigrees

Chromosome 1q has been implicated in the etiology of schizophrenia in several independent studies. However, the peak linkage findings have been dispersed over a large chromosomal region, with negative findings in this region also being reported. Our group has previously observed linkage on chromosome 1q42, maximizing within the DISC1 gene, which has also been implied in the etiology of schizophrenia based on functional studies. In the study presented here, we genotyped 300 polymorphic markers on chromosome 1 using a study sample of 70 families with multiple individuals affected with schizophrenia or related conditions, independent of the study samples in our previous reports. We again found evidence for linkage on 1q42 maximizing within the DISC1 gene (rs1000731, lod=2.70). Further, a haplotype containing the most strongly linked markers showed some evidence of association with the disease. This replicates the previous linkage finding in the same region and constitutes supportive evidence for a susceptibility gene in this region.

Time patterns and seasonal mismatch in suicide

OBJECTIVE

Physical time-givers may have a modifying effect on the time patterns of death from suicide.

METHOD

Data on a total of 1397 suicides in Finland over a year were collected using the method of psychological autopsy. We linked versatile information on each individual to meteorological data adjusted for local weather conditions, and to the universal astronomic data.

RESULTS

The number of suicides with seasonal mismatch was greater than the expected in the northernmost region of the country (P = 0.03). The northern location was the most significant predictor of such suicides (P = 0.001). They were associated with the changes in ambient temperature during the preceding day (P < 0.00001), the changes to colder preceding suicides in the spring.

CONCLUSION

Our findings show that mismatch between the changes in ambient temperature and those in the length of day may precede death from suicide in some individuals.

Health care contacts before and after attempted suicide among adolescent and young adult versus older suicide attempters

BACKGROUND

The pattern of all health care contacts among young people before and after attempted suicide is not well documented. Neither is it known if the health care contacts of young suicide attempters differ from those of older suicide attempters. This study investigated the age-related clinical characteristics of suicide attempters and the pattern of their contacts with health care before and after attempted suicide in different age groups, particularly adolescence and young adulthood.

METHOD

All consecutive 1198 suicide attempters treated in hospital emergency rooms in Helsinki between January 1997 and January 1998 were identified and divided into three age groups (15-24 years, 25-39 years, 40 years and over). Data were gathered on all health care contacts 1 year before and after the index attempt.

RESULTS

Although adolescent and young adult suicide attempters suffered from severe mental disorders, a remarkable proportion of them were left without psychiatric consultation and aftercare recommendation following the attempt. Two-thirds of 15-19-year-old male suicide attempters had no treatment contact during the month before the attempt, while a quarter of them were referred to psychiatric consultation and a half had no healthcare contact in the month following the attempt.

CONCLUSIONS

These findings indicate considerable scope for improvement in the assessment of young suicide attempters and their referral to aftercare.

Bipolar disorder susceptibility region on Xq24-q27.1 in Finnish families

Bipolar disorder (BPD) is a common disorder characterized by episodes of mania, hypomania and depression. The genetic background of BPD remains undefined, although several putative loci predisposing to BPD have been identified. We have earlier reported significant evidence of linkage for BPD to chromosome Xq24-q27.1 in an extended pedigree from the late settlement region of the genetically isolated population of Finland. Further, we established a distinct chromosomal haplotype covering a 19 cM region on Xq24-q27.1 co-segregating with the disorder. Here, we have further analyzed this X-chromosomal region using a denser marker map and monitored X-chromosomal haplotypes in a study sample of 41 Finnish bipolar families. Only a fraction of the families provided any evidence of linkage to this region, suggesting that a relatively rare gene predisposing to BPD is enriched in this linked pedigree. The genome-wide scan for BPD predisposing loci in this large pedigree indicated that this particular X-chromosomal region provides the best evidence of linkage genome-wide, suggesting an X-chromosomal gene with a major role for the genetic predisposition of BPD in this family.

Bright-light exposure combined with physical exercise elevates mood

BACKGROUND

Physical exercise alleviates depressive symptoms, as does exposure to bright light, especially in those with seasonal variation. Our objective was to compare the effect of exercise alone or combined with morning bright light on mood and the health-related quality of life in healthy subjects.

METHODS

Study subjects were working-age adults, randomized in two groups (n=80): exercise in bright light (group A), or exercise in normal indoor illumination (group B). Intervention lasted for 8 weeks and questionnaire data on mood and the health-related quality of life were collected at study entry, and at weeks 4 and 8.

RESULTS

Physical exercise both in normal indoor illumination and in bright light was effective at alleviating depressive symptoms. The exercise was significantly more effective at alleviating so-called atypical depressive symptoms when combined with bright-light exposure.

LIMITATIONS

There was no active placebo condition, but a comparative, randomized trial was executed.

CONCLUSIONS

Physical exercise in bright light had a positive effect on mood and health-related quality of life in a sample of healthy, working-age people. Further research is needed to explore the mechanisms of the apparent additive effect of exercise and light.

Major depressive episode among young adults: CIDI-SF versus SCAN consensus diagnoses

BACKGROUND

We aimed to evaluate the diagnostic accuracy of a highly structured diagnostic interview in relation to a semi-structured diagnostic procedure. We compared the World Health Organization Composite International Diagnostic Interview Short Form (CIDI-SF) in diagnosing major depressive episode (MDE) to consensus diagnoses based on the SCAN interview (Schedules for Clinical Assessment in Neuropsychiatry).

METHOD

Subjects comprised a follow-up sample of 239 20-24-year-old former high-school students who were administered the SCAN and immediately thereafter the CIDI-SF. Concordance was estimated for 12-month MDE, using different cut-points of the CIDI-SF and for any affective disorders.

RESULTS

Correspondence between instruments was moderate for MDE (kappa = 0.43, sensitivity 0.71, specificity 0.82), but better for any affective disorder (kappa = 0.60, sensitivity 0.70, specificity 0.90). Most false negatives suffered from their depression as much as those correctly identified by the CIDI-SF. False negativity was mainly due to not endorsing the stem questions of the CIDI-SF. Of the false positives almost half had an affective disorder other than MDE.

CONCLUSIONS

The CIDI-SF seems to function best in identifying a broader category of affective disorders. It could be useful in large-scale community surveys where more extensive psychiatric interviews are not feasible.

Maintenance and manipulation in spatial working memory: dissociations in the prefrontal cortex

Two experiments were conducted to compare thec ries of the functional organization of spatial working memory within the human prefrontal cortex. In Experiment I, memory set size for locations was parametrically varied, allowing for the assessment of BOLD signal across maintenance requirements. In the sec ond experiment, manipulation of spatial information held in working memory was contrasted with simple maintenance of that information. Both experiment evoked significant activity in a distributed spatia working memory network. Although dorsolateral prefrontal activation increased monotonically with memory set size, this region was differentially engaged in task conditions involving explicit manipulation of in ternal representations. Activation in the superior frontal sulcal region was associated with maintenance of spatial information, increasing with memory se size. In contrast, ventrolateral prefrontal activation was present only at the highest memory set size, possibly due to the differential use of organizational strategies with more complex stimuli. These results sup port claims that the dorsolateral prefrontal cortex is involved in the manipulation of internal representa tions and that the superior frontal sulcal region is involved in the maintenance of spatial information but they suggest a complex role for the ventrolatera prefrontal region.

Genome-wide scan in a nationwide study sample of schizophrenia families in Finland reveals susceptibility loci on chromosomes 2q and 5q

We have previously carried out two genome-wide scans in samples of Finns ascertained for schizophrenia from national epidemiological registers. Here, we report data from a third genome scan in a nationwide Finnish schizophrenia study sample of 238 pedigrees with 591 affected individuals. Of the 238 pedigrees, 53 originated from a small internal isolate (IS) on the eastern border of Finland with a well established genealogical history and a small number of founders, who settled in the community 300 years ago. The total study sample of over 1200 individuals were genotyped, using 315 markers. In addition to the previously identified chromosome 1 locus, two new loci were identified on chromosomes 2q and 5q. The highest LOD scores were found in the IS families with marker D2S427 (Z(max) = 4.43) and in the families originating from the late settlement region with marker D5S414 (Z(max) = 3.56). In addition to 1q, 2q and 5q, some evidence for linkage emerged at 4q, 9q and Xp, the regions also suggested by our previous genome scans, whereas, in the nationwide study sample, the region at 7q failed to show further evidence of linkage. The chromosome 5q finding is of particular interest, since several other studies have also shown evidence for linkage in the vicinity of this locus.

Genetic influences on brain structure

Here we report on detailed three-dimensional maps revealing how brain structure is influenced by individual genetic differences. A genetic continuum was detected in which brain structure was increasingly similar in subjects with increasing genetic affinity. Genetic factors significantly influenced cortical structure in Broca's and Wernicke's language areas, as well as frontal brain regions (r2(MZ) > 0.8, p < 0.05). Preliminary correlations were performed suggesting that frontal gray matter differences may be linked to Spearman's g, which measures successful test performance across multiple cognitive domains (p < 0.05). These genetic brain maps reveal how genes determine individual differences, and may shed light on the heritability of cognitive and linguistic skills, as well as genetic liability for diseases that affect the human cortex.

Poststroke depression in acute phase after stroke

We studied factors associated with acute poststroke depression in 100 patients, aged 27-70, 2 weeks after their first clinically significant stroke. Depressive symptoms were relatively common (27% Beck Depression Inventory > or =10), but the prevalence of major depression was only 5.6%. Older patients were most vulnerable to poststroke depression. Patients with left hemisphere lesion had no more depression than other patients, but when the lesion was in the left hemisphere or in the brainstem, stroke severity was associated with depression.

Female homicide offenders have greatly increased mortality from unnatural deaths

The mortality of female homicidal offenders has scarcely been studied. Our aim was to examine the mortality of homicidal women in Finland using a representative nation-wide material. The data consisted of all 132 women who underwent forensic psychiatric examinations after committing homicide or attempted homicide in 1982-1992. We analysed their rate and cause of death during follow-up using standardised mortality ratios (SMRs) and the official classification of death. The mean follow-up time for dead subjects was 7 years (S.D. 4), and for the rest 11 years (S.D. 3). There were 22 observed deaths, the expected value being 1.3 (SMR 17.4). The SMR for unnatural deaths was 226 and for suicides 425. The SMRs for women below 40 years were over 220. In conclusion, homicidal women have an over 200-fold risk of unnatural death, rising to over 400-fold for suicide. This should be taken into consideration in planning discharge programmes for homicidal offenders.

Long-term risk factors for suicide mortality after attempted suicide--findings of a 14-year follow-up study

OBJECTIVE

To determine the risk of suicide over a 14-year follow-up period, and to investigate the long-term risk factors for suicide using survival analysis.

METHOD

Data were collected on all unselected deliberate self-poisoning patients (n=1018) treated during 1983 in the emergency unit of Helsinki University Central Hospital.

RESULTS

By the end of the 14 -year follow-up period 222 (21.7%) of these patients had died. Sixty-eight (6.7%) had committed suicide; 44 (9.2%) men and 24 (4.5%) women. The long-term risk factors for suicide were male sex, previous psychiatric treatment, previous suicide attempts, somatic disease and a self-reported 'wish to die' motive for the index suicide attempt.

CONCLUSION

The essential risk factors for suicide were being male and having previous suicide attempts. In addition, history of earlier psychiatric treatment, presence of somatic disease and genuine intent to die in the index suicide attempt suggest that the long-term risk has remained high for over a decade. The findings emphasize the need for long-term planning and treatment of suicide attempters met in the emergency room of general hospitals.

Regional variation in the incidence of schizophrenia in Finland: a study of birth cohorts born from 1950 to 1969

BACKGROUND

We investigated whether there is regional variation in the incidence of schizophrenia and if so. whether it is caused by urban-rural differences, larger spatial clustering, or both. To control for the effect of migration, we examined regional variation in the incidence according to place of birth.

METHODS

Finnish birth cohorts born from 1950 to 1969 were followed in the National Hospital Discharge Register from 1969 until 1991, and all cases of schizophrenia (ICD-8 or ICD-9 295) were identified (N = 14828). Forty-eight of the 559 municipalities were classified as urban and 25% of the Finnish population lived in these municipalities in 1960. For the analysis of spatial clustering, municipalities were grouped into 57 functional small-areas. We used Poisson regression model with the number of births of individuals who later developed schizophrenia as a response variable, and place of birth (urban/rural), birth cohort (1950-54, 1955-9, 1960-64, and 1965-9), functional small-area units, and sex as response variables.

RESULTS

The incidence was slightly higher among the rural-born in the oldest birth cohort. In the other cohorts, it was higher among the urban-born, and the difference between urban and rural born increased in the youngest cohorts. Significant spatial clustering of schizophrenia was observed in eastern Finland.

CONCLUSIONS

Urban birth is a risk factor for schizophrenia in Finland in cohorts born since 1955. However, genuine spatial clustering of schizophrenia in eastern Finland was also observed, possibly caused by genetic isolation.

Chromosome 1 loci in Finnish schizophrenia families

We have earlier reported evidence for linkage to two regions on chromosome 1q32--q42 in schizophrenia families collected for two separate studies in Finland. Here we report the results of a fine mapping effort aimed at further definition of the chromosomal region of interest using a large, population-based study sample (221 families, 557 affected individuals). Most affecteds (78%) had a DSM-IV schizophrenia diagnosis and the remaining had schizophrenia spectrum disorders. We genotyped a total of 147 microsatellite markers on a wide 45 cM region of chromosome 1q. The results were analyzed separately for families originating from an internal isolate of Finland and for families from the rest of Finland, as well as for all families jointly. We used traditional two-point linkage analysis, SimWalk2 multipoint analysis and a novel gamete-competition association/linkage method. Evidence for linkage was obtained for one locus in the combined sample (Z(max) = 2.71, D1S2709) and in the nuclear families from outside the internal isolate (Z(max) = 3.21, D1S2709). In the families from the internal isolate the strongest evidence for linkage was obtained with markers located 22 cM centromeric from this marker (Z(max) = 2.30, D1S245). Multipoint analysis also indicated these loci. Some evidence for association with several markers was observed using the gamete-competition method. Interestingly, the strongest evidence for linkage in the combined study sample was obtained for marker D1S2709, which is an intragenic marker of the DISC1 gene, previously suggested as a susceptibility gene for schizophrenia. These results are consistent with the presence of susceptibility gene(s) in this chromosomal region, a result also implied in other recent family studies of schizophrenia.