Contrasted patterns of hyperdiversification in Mediterranean hotspots

Dating the Tree of Life has now become central to relating patterns of biodiversity to key processes in Earth history such as plate tectonics and climate change. Regions with a Mediterranean climate have long been noted for their exceptional species richness and high endemism. How and when these biota assembled can only be answered with a good understanding of the sequence of divergence times for each of their components. A critical aspect of dating by using molecular sequence divergence is the incorporation of multiple suitable age constraints. Here, we show that only rigorous phylogenetic analysis of fossil taxa can lead to solid calibration and, in turn, stable age estimates, regardless of which of 3 relaxed clock-dating methods is used. We find that Proteaceae, a model plant group for the Mediterranean hotspots of the Southern Hemisphere with a very rich pollen fossil record, diversified under higher rates in the Cape Floristic Region and Southwest Australia than in any other area of their total distribution. Our results highlight key differences between Mediterranean hotspots and indicate that Southwest Australian biota are the most phylogenetically diverse but include numerous lineages with low diversification rates.     

Impaired executive performance in healthy siblings of schizophrenia patients in a population-based study

There is increasing evidence that healthy siblings of schizophrenia patients have similar, although milder, neuropsychological deficits than their affected family members. However, the interpretation of these findings has been complicated by methodological differences, for example the selection of relatives studied and the sensitivity of tests used. We studied neuropsychological functioning in schizophrenia families in representative, population-based samples of schizophrenia patients (n=81) and healthy siblings (n=78) from 58 families, and control subjects (n=70). We found that the healthy sibling group was impaired in tests measuring performance speed and executive functions. The patients were significantly impaired in all neuropsychological variables studied when compared with the control subjects, and also when compared with the healthy siblings. The effects of age, sex and education were controlled for. In conclusion, in a study of representative, population-based sample the healthy siblings of schizophrenia patients demonstrated deficits in processing speed and executive functions.     

An international multicenter randomized double-blind controlled trial of lamotrigine and sustained-release carbamazepine in the treatment of newly diagnosed epilepsy in the elderly

PURPOSE: To assess the comparative effectiveness, efficacy, and tolerability of lamotrigine (LTG) and sustained-release carbamazepine (CBZ) in the treatment of newly diagnosed epilepsy in the elderly. METHODS: Patients aged 65 years or older, who had experienced at least two unprovoked partial and/or generalized tonic-clonic seizures, were randomized to receive LTG (n=93) or CBZ (n=92) according to a multicenter double-blind, parallel-group design. Trial duration was 40 weeks and included a 4-week dose escalation followed by a maintenance phase during which dosages could be adjusted according to response. Initial, maintenance and maximum dosages were 25 mg, 100 mg, and 500 mg per day for LTG, and 100 mg, 400 mg, and 2,000 mg per day for CBZ, respectively. The primary end point was retention in the trial. RESULTS: In the LTG group, 68 patients (73%) completed the 40-week study period compared with 61 (67%) in the CBZ group, a nonsignificant difference. Time to withdrawal from any cause did not differ between groups (p=0.34). The number of subjects who completed the 40-week period and were seizure free in the last 20 weeks was 48 (52%) in the LTG group and 52 (57%) in the CBZ group. Adverse events leading to withdrawal occurred in 13 (14%) subjects in the LTG group and 23 (25%) subjects in the CBZ group. CONCLUSION: LTG and CBZ showed comparable effectiveness, with a trend for higher seizure-free rates for CBZ and better tolerability for LTG. Differences in outcome compared with previous trials may be related to different dosing rates and use of a sustained-release formulation for CBZ.     

Alexithymia and occupational burnout are strongly associated in working population

OBJECTIVE: The relationship between alexithymia and occupational burnout has not previously been studied. We investigated the association between alexithymia and occupational burnout in a representative nationwide population health study. METHODS: This study was a part of the Finnish Health 2000 Study. The nationally representative sample comprised 3322 employees aged 30-64 years. Alexithymia was measured with the 20-item Toronto Alexithymia Scale (TAS-20) and occupational burnout with the Maslach Burnout Inventory-General Survey. Sociodemographic and health-related variables including depression were treated as confounders in the logistic regression analyses, which were performed alternately with TAS-20 total score and the scores of the three TAS-20 factor scales as alexithymia variables. RESULTS: Alexithymia and its three facets were significantly associated with occupational burnout even when controlled for confounding factors. CONCLUSIONS: Even though both alexithymia and depression are associated with burnout, alexithymia may be an independent risk factor for occupational burnout.     

The role of DTNBP1, NRG1, and AKT1 in the genetics of schizophrenia in Finland

Several putative schizophrenia susceptibility genes have recently been identified. Significant associations between schizophrenia and neuregulin 1 (NRG1) and dysbindin (DTNBP1) were first reported in 2002 and studies in several populations have since independently reported positive associations to these gene regions. Further, both tentative functional and genetic data have implicated the role of AKT1 in the genetic background of this disorder. However, findings have not been consistent in all populations. We investigated the allelic diversity of these three genes NRG1, DTNBP1 and AKT1 in a representative nation-wide study sample of 441 Finnish schizophrenia families consisting of 865 affected individuals, in order to assess their role in one of the largest population-based study samples. DTNBP1 and AKT1 failed to show evidence of association, whereas two SNPs in the 3' region of the NRG1 gene yielded suggestive evidence of association (p=0.012 and p=0.048) in family-based association analyses. Thus, our study does not indicate that AKT1 or DTNBP1 play a role in the etiology of schizophrenia in the Finnish population. Furthermore, results do not support a major role for NRG1, but we cannot completely exclude a minor role of this gene in the Finnish population.     

Different vulnerability indicators for psychosis and their neuropsychological characteristics in the Northern Finland 1986 Birth Cohort

This study is one of very few that has investigated the neuropsychological functioning of both familial and clinical high risk subjects for psychosis. Participants (N = 164) were members of the Northern Finland 1986 Birth Cohort in the following four groups: familial risk for psychosis (n = 62), clinical risk for psychosis (n = 20), psychosis (n = 13), and control subjects (n = 69). The neurocognitive performance of these groups was compared across 19 cognitive variables. The two risk groups did not differ significantly from controls, but differed from the psychosis group in fine motor function. Neuropsychological impairments were not evident in a non-help-seeking high-risk sample.     

Mobility limitations in persons with psychotic disorder: findings from a population-based survey

BACKGROUND: There are few reports on mobility limitations in persons with psychotic disorder although restrictions in mobility may aggravate the general functional limitations of these patients. Our aim was to investigate mobility limitations among subjects with psychotic disorder in a general population-based sample. METHODS: A nationally representative sample of 6,927 persons aged 30 and older self-reported mobility limitations in an interview and was examined in performance tests. Diagnostic assessment of DSM-IV psychotic disorders combined SCID interview and case note data. Lifetime-ever diagnoses of psychotic disorder were classified into schizophrenia, other nonaffective psychotic disorders and affective psychoses. RESULTS: Self-reported mobility limitations were highly prevalent in persons with schizophrenia and other nonaffective psychosis, but not in the affective psychosis group. After adjusting for age and sex, persons with schizophrenia and other nonaffective psychoses but not affective psychoses had significantly increased odds of having both self-reported and test-based mobility limitations as well as weak muscle strength. Schizophrenia remained an independent predictor of mobility limitations even after controlling for lifestyle-related factors and chronic medical conditions. Among persons with nonaffective psychoses, higher levels of negative symptoms predicted mobility limitations. CONCLUSION: Self-reported mobility limitations are prevalent already at a young age in persons with schizophrenia and other nonaffective psychotic disorders, and among older persons with these disorders both self-reported limitations and measured performance tests show lower capacity in mobility. Difficulties in mobility are associated with negative symptoms. Mental health care professionals should pay attention to mobility limitations in persons with psychotic disorder.     

Prospective relations between alexithymia,substance use and depression: findings from a National Birth Cohort

Abstract

Purpose: This study examined a developmental model that links affect-regulation difficulties in childhood with three dimensions of alexithymia in adolescence (difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking) and substance use and depression in adulthood, while accounting for cumulative contextual risk in childhood, and testing potential gender moderation.

Methods: Multiple group path analyses were conducted using data from the Northern Finland Birth Cohort 1986 (N?=?6963). Analyses used data collected during prenatal/birth, childhood, adolescence, and young adulthood periods.

Results: Our examination of early precursors for alexithymia indicated that the associations of affect-regulation problems in childhood with alexithymia were stronger for girls, potentially putting girls with affect-regulation difficulties in childhood at higher risk for developing alexithymia in adolescence. The associations of cumulative contextual risk in childhood with alexithymia, substance use disorder, and depression diagnosis in adulthood were significant for both girls and boys. Our findings in regard to substance use and depression disorders revealed that alexithymia in adolescence predicted depression diagnosis in adulthood, particularly due to a contribution from the alexithymia domain of ‘difficulties identifying feelings.’ However, none of the alexithymia domains was directly associated with substance use disorder in adulthood.

Conclusions: Our study contributes to research that links alexithymia with difficulties in affect regulation and cumulative contextual risk in childhood, yielding findings that may be relevant for preventive interventions.     

Serum lipids in schizophrenia and other functional psychoses: a general population northern Finland 1966 birth cohort survey

OBJECTIVE: To compare fasting serum lipid concentrations of subjects with schizophrenia with a comparison group. METHOD: The study sample consists of 5654 members of the northern Finland 1966 birth cohort who participated in the field study with blood samples after overnight fasting and clinical examination in 1997-98. Total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides (TG) and glucose were analyzed. Analysis of variance were used for comparing differences in lipids means between diagnostic categories. RESULTS: Mean fasting TC in subjects with schizophrenia was 20 mg/dl higher than in the comparison group. TC and TG levels in the group of other psychoses resembled the schizophrenia group. CONCLUSION: Blood lipid levels in subjects with schizophrenia and other functional psychoses were high. As these persons are at special risk for hyperlipidemia their lipid levels should be regularly monitored, and cholesterol lowering diet, as well as medication, should be considered.