Multimodal imaging of a tescalcin (TESC)-regulating polymorphism (rs7294919)-specific effects on hippocampal gray matter structure

In two large genome-wide association studies, an intergenic single-nucleotide polymorphism (SNP; rs7294919) involved in TESC gene regulation has been associated with hippocampus volume. Further characterization of neurobiological effects of the TESC gene is warranted using multimodal brain-wide structural and functional imaging. Voxel-based morphometry (VBM8) was used in two large, well-characterized samples of healthy individuals of West-European ancestry (Münster sample, N=503; SHIP-TREND, N=721) to analyze associations between rs7294919 and local gray matter volume. In subsamples, white matter fiber structure was investigated using diffusion tensor imaging (DTI) and limbic responsiveness was measured by means of functional magnetic resonance imaging (fMRI) during facial emotion processing (N=220 and N=264, respectively). Furthermore, gene x environment (G × E) interaction and gene x gene interaction with SNPs from genes previously found to be associated with hippocampal size (FKBP5, Reelin, IL-6, TNF-α, BDNF and 5-HTTLPR/rs25531) were explored. We demonstrated highly significant effects of rs7294919 on hippocampal gray matter volumes in both samples. In whole-brain analyses, no other brain areas except the hippocampal formation and adjacent temporal structures were associated with rs7294919. There were no genotype effects on DTI and fMRI results, including functional connectivity measures. No G × E interaction with childhood maltreatment was found in both samples. However, an interaction between rs7294919 and rs2299403 in the Reelin gene was found that withstood correction for multiple comparisons. We conclude that rs7294919 exerts highly robust and regionally specific effects on hippocampal gray matter structures, but not on other neuropsychiatrically relevant imaging markers. The biological interaction between TESC and RELN pointing to a neurodevelopmental origin of the observed findings warrants further mechanistic investigations.

Identification of a biological signature for schizophrenia in serum

Biomarkers are now used in many areas of medicine but are still lacking for psychiatric conditions such as schizophrenia (SCZ). We have used a multiplex molecular profiling approach to measure serum concentrations of 181 proteins and small molecules in 250 first and recent onset SCZ, 35 major depressive disorder (MDD), 32 euthymic bipolar disorder (BPD), 45 Asperger syndrome and 280 control subjects. Preliminary analysis resulted in identification of a signature comprised of 34 analytes in a cohort of closely matched SCZ (n=71) and control (n=59) subjects. Partial least squares discriminant analysis using this signature gave a separation of 60-75% of SCZ subjects from controls across five independent cohorts. The same analysis also gave a separation of ~50% of MDD patients and 10-20% of BPD and Asperger syndrome subjects from controls. These results demonstrate for the first time that a biological signature for SCZ can be identified in blood serum. This study lays the groundwork for development of a diagnostic test that can be used as an aid for distinguishing SCZ subjects from healthy controls and from those affected by related psychiatric illnesses with overlapping symptoms.

[Neurogenetics of emotional processes. Neuroimaging findings as endophenotypes for depression]

Major depression is one of the most frequent and serious psychiatric diseases. Although the disease is highly heritable, the search for candidate genes has been of limited success hitherto. The complex, polygenetic hereditary transmissions coding for heterogeneous, clinically defined phenotypes such as major depression may be better identified using the endophenotype approach. A recent study, reporting an association of the risk allele in a serotonin transporter polymorphism (5-HTTLPR) with increased amygdala responsiveness to aversive stimuli, stimulated the new research field of imaging genetics, which is characterized by the choice of neurobiological activity patterns as endophenotypes. This review discusses recent studies from this rapidly growing research field, focussing on genetic effects on cortico-limbic circuitries during emotion processing. Evidence is reviewed suggesting that potential risk-alleles for depression are associated with functional cortico-limbic abnormalities, which frequently occur in patients with major depression.

Association between genetic variants of the metabotropic glutamate receptor 3 (GRM3) and cognitive set shifting in healthy individuals

Set-shifting and maintenance are complex cognitive processes, which are often impaired in schizophrenia. The genetic basis of these processes is poorly understood. We aimed to investigate the association between genetic variants of the metabotropic glutamate receptor 3 (GRM3) and cognitive set-shifting in healthy individuals. The relationship between 14 selected single nucleotide polymorphisms (SNPs) of the GRM3 gene and cognitive set-shifting as measured by perseverative errors using the modified card sorting test (MCST) was analysed in a sample of N = 98 young healthy individuals (mean age in years: 22.7 +/- 0.19). Results show that SNP rs17676277 is related to the performance on the MCST. Subjects with the TT genotype showed significantly less perseverative errors as compared with the AA (P = 0.025) and AT (P = 0.0005) and combined AA/AT genotypes (P = 0.0005). Haplotype analyses suggest the involvement of various SNPs of the GRM3 gene in perseverative error processing in a dominant model of inheritance. The findings strongly suggest that the genetic variation (rs17676277 and three haplotypes) in the metabotropic GRM3 is related to cognitive set-shifting in healthy individuals independent of working memory. However, because of a relatively small sample size for a genetic association study, the present results are tentative and require replication.

[Schizophrenia-like personality disorders]

According to DSM-IV the cluster A personality disorders include paranoid, schizoid, and schizotypal personality disorders. There exists a phenomenological similarity between the experience and behaviour of the so-called odd or eccentric personality disorders and the symptoms of schizophrenia. Evidence of common etiological factors is still the best for the schizotypal personality disorder. The cluster A personality disorders are among the less common personality disorders with a high co-occurrence. Present findings about the neurobiological substrate of the schizotypal personality disorder are discussed also taking neuropsychological results into consideration. A central prerequisite of psychotherapeutic and pharmacological treatment of cluster A personality disorders is a strong therapeutic patient relationship.

Complicated grief after traumatic loss: a 14-month follow up study

The traumatic loss of an unborn child after TOP due to fetal malformation and/or severe chromosomal disorders in late pregnancy is a major life-event and a potential source of serious psychological problems for those women. To obtain information on the course of grief following a traumatic loss, 62 women who had undergone TOP between the 15th and 32nd gestational week were investigated in a longitudinal study design and compared with 65 women after spontaneous delivery of a full-term healthy child. Grief, posttraumatic stress, depression, anxiety and psychiatric disorders were evaluated 14 days, 6 months and 14 months after the event, implementing validated self-report and clinician rated instruments. Compared to women after spontaneous delivery, women after induced TOP were significantly more stressed regarding all psychological outcomes at all three measuring points. Especially, 14 months after TOP 13.7% of the women fulfilled all criteria of a complicated grief diagnoses following Horowitz et al. (1997, Am J Psychiat 154:7904-7910). 16.7% were diagnosed as having a manifest psychiatric disorder according to DSM-IV. All in all, 25% of these women were critically affected by the traumatic loss. TOP for fetal anomaly is to be seen as a major life event, which causes complicated grief reactions and psychiatric disorders for a substantial number of women.

Serotonergic genes modulate amygdala activity in major depression

Serotonergic genes have been implicated in the pathogenesis of depression probably via their influence on neural activity during emotion processing. This study used an imaging genomics approach to investigate amygdala activity in major depression as a function of common functional polymorphisms in the serotonin transporter gene (5-HTTLPR) and the serotonin receptor 1A gene (5-HT(1A)-1019C/G). In 27 medicated patients with major depression, amygdala responses to happy, sad and angry faces were assessed using functional magnetic resonance imaging at 3 Tesla. Patients were genotyped for the 5-HT(1A)-1019C/G and the 5-HTTLPR polymorphism, including the newly described 5-HTT-rs25531 single nucleotide polymorphism. Risk allele carriers for either gene showed significantly increased bilateral amygdala activation in response to emotional stimuli, implicating an additive effect of both genotypes. Our data suggest that the genetic susceptibility for major depression might be transported via dysfunctional neural activity in brain regions critical for emotion processing.

Incidental learning of food and emotional words in women with anorexia nervosa

Prior research suggests that anorexic patients show a memory bias for fattening foods when they are processed in depth or with reference to the self. The present study examined whether anorexic subjects exhibit a bias for fattening foods when these are presented as task-irrelevant distractor stimuli. It also investigated whether anorexic patients pay less attention to emotion stimuli. A sequential word-word evaluation task was administered to 11 inpatients with anorexia nervosa and 11 non-dieting normal subjects. There were four types of distractor words: high caloric foods, positive, negative, and neutral. Anorexic patients recalled no more food words but fewer neutral and positive words than normal subjects. The present data suggest that, compared to healthy young women, anorexic patients show no memory bias for fattening foods when these data are presented as peripheral environmental information. Anorexic patients are perceptually no less sensitive to negative emotional information than normal subjects.

N-acetylaspartate levels of left frontal cortex are associated with verbal intelligence in women but not in men: a proton magnetic resonance spectroscopy study

The left frontal cortex plays an important role in executive function and complex language processing inclusive of spoken language. The purpose of this work was to assess metabolite levels in the left and right prefrontal cortex and left anterior cingulum by proton magnetic resonance spectroscopy and relate results to verbal intelligence (Wechsler Adult Intelligence Scale revised) in a sample of college-educated healthy volunteers (dorsolateral prefrontal cortex [DLPFC]: n=52, 23 females, and left anterior cingulum: n=62, 22 females; age range: 20-75 years). In women only, N-acetylaspartate in the DLPFC and in the left anterior cingulate cortex was positively correlated with vocabulary scores. Our data support the hypothesis of existing gender differences regarding the involvement of the left frontal cortex in verbal processing as reflected in different correlations of specific metabolites with verbal scores.

[A critique of the construct "alexithymia" and its measurement--the weakness of self-report and the opportunities of an objective assessment approach]

Approximately thirty years ago the term alexithymia was coined but it is still open which characteristics have to be considered core symptoms of alexithymia. A selective review of recent expert definitions reveals dynamism in defining the alexithymia construct. At present, the self-report Toronto-Alexithymia-Scales (TAS) are the most frequently used measures of alexithymia. Empirical findings regarding various aspects of validity (factorial, concurrent, and experimental construct validity data) question the validity of the Toronto-Alexithymia-Scales. Alexithymia as measured by the TAS appears not to be consistently related to physiological, affect decoding or affective vigilance characteristics. The heterogeneity of the results could be due to the fact that non-alexithymic persons such as depressed or socially anxious individuals yield high scores on the TAS; on the other hand self-report appears to be in principle a methodologically inadequate approach for the assessment of alexithymia. Objective or direct measures of alexithymic characteristics as the Levels of Emotional Awareness Scale or the prototypicity analysis of mood diaries based on adjective checklists seem to be promising assessment methods for future research.

Detection of facial expressions of emotions in depression

Research on perceptual and attentional processes in depression has shown that depressed as opposed to nondepressed individuals do not exhibit a positive perceptual bias in multistimulus representations. In the present study a face-in-the-crowd task was applied to examine the relationship between depression and spatial detection of facial expression of positive and negative emotions. A face-in-the-crowd task was administered to 30 subjects (15 clinically stabilized depressed inpatients and 15 normal subjects) using displays of schematic faces. Depressed subjects showed no performance differences in the detection of negative faces and no differences in decision latency for the control condition (all neutral faces) compared to normal subjects. Depressed subjects, however, were significantly slower in responding to positive faces than normal subjects. Our data suggest that depressive mood is associated with a reduced spatial attention to positive facial expression and not with an abnormal spatial processing of negative facial expression. An implication is that lowered vigilance for facial expressions of joy and happiness may affect adversely interpersonal relationships in depressed subjects.

Attention training in the cognitive rehabilitation of schizophrenic patients: a review of efficacy studies

OBJECTIVE

To review the literature on effects of attention and cognitive training on attentional functioning in schizophrenic patients.

METHOD

Relevant efficacy studies were identified by literature searches (in Medline, Current Contents, Psyclit, and Psyndex databases) and through the reference lists of key papers.

RESULTS

Re-examination of findings from nine methodologically adequate studies using computer-based or non-computer-based training procedures provided inconsistent results. On 16 of 35 outcome measures significant performance improvements were observed from pre-treatment to post-treatment but on the majority of the applied measures no performance improvement could be determined. In general, treatment effect sizes but also power of tests were low. For nearly all the outcome measures for which differential training effects were reported there also exist contradictory outcome results.

CONCLUSION

There is inconclusive evidence that attention training is effective in schizophrenia. Longitudinal efficacy studies are needed in which different aspects of attention are systematically exercised and assessed.

20-Item Toronto Alexithymia Scale: do difficulties describing feelings assess proneness to shame instead of difficulties symbolizing emotions?

A hallmark of alexithymia is the difficulty putting emotional states into words which has to be differentiated from problems to communicate emotion to others. Shame proneness is a personality trait that is expected to be closely related to a reduced emotional self-disclosure in social interactions. The present investigation was conducted to examine construct validity of the Difficulties Describing Feelings scale of the 20-Item Toronto Alexithymia Scale (TAS-20). The TAS-20 was administered to 68 subjects (30 psychiatric inpatients and 38 normals) along with the Levels of Emotional Awareness Scale (LEAS), a direct measure of the ability to express feelings verbally, and the Shame-Guilt-Scale. Difficulties Describing Feelings was associated with shame assessing scales but not with guilt assessing scales or the LEAS. Thus, in view of our data one should be cautious in interpreting scores from the TAS-20 scale Difficulties Describing Feelings as indices of a difficulty to symbolize one's emotions. Instead, this TAS-20 scale seems to evaluate aspects of social shame.

Comorbidity of schizophrenia and prelingual deafness: its impact on social network structures

BACKGROUND

Prelingually deaf persons usually gain only a rudimentary command of speech and prefer sign language to communicate within the deaf community without the handicap they experience in the hearing world. Maintaining social contact within this rather scattered community, however, requires higher degrees of social initiative and mobility. The aim of the present paper was to study the quantity and quality of social integration among a group of prelingually deaf schizophrenic patients (n = 49) and two control groups comprising prelingually deaf psychiatric but non-psychotic patients (n = 38) and hearing schizophrenic patients (n = 30), with account being taken of the special socialisation conditions of deaf persons and of their cultural standards and values.

METHOD

Data were collected with the help of semi-structured interviews; with the deaf patients these were conducted in German sign language. Using rating procedures we assessed seven social support components, selected items from a history schedule for schizophrenia, and the probands' visual and verbal language skills.

RESULTS

The social networks of the two deaf groups were found to have larger gaps than those of the hearing schizophrenic patients, with significant differences being registered most clearly in the comparison between deaf schizophrenic and hearing schizophrenic patients. Comparison of the verbal and visual language skills of the two deaf groups revealed a substantial deficit among the deaf schizophrenics. Visual language skills were found to correlate more strongly than verbal language skills with the social support components.

CONCLUSION

Prelingual deafness has a strong impact on the course of schizophrenia. In the long run, many of these patients belong to a "minority within a minority".

Backward masking in schizophrenia: time course of visual processing deficits during task performance

Backward masking deficits have been put forward as potential psychological markers for vulnerability to schizophrenia. This study was conducted to investigate whether schizophrenic patients improve their performance on a backward masking task during a single test session. The ability of a degraded stimulus version of the masking task to act as a specific diagnostic marker for paranoid schizophrenia (versus affective disorder) was also investigated. The backward masking task was performed on 18 paranoid schizophrenic patients, 18 unipolar depressed patients, and 18 non-psychiatric controls. Paranoid schizophrenic patients were included because they tend to show normal performance with traditional masking protocols. Schizophrenic patients made significantly more detection errors compared to depressives and non-psychiatric controls where interstimulus intervals (ISIs) longer than 14 ms were used. Unlike depressed patients and non-psychiatric controls, schizophrenic patients showed no reduction in error rate during the entire period over which the backward masking task was performed. The constant error rate which was observed at an ISI of 114 ms suggests that schizophrenic patients cannot attenuate the disruption effect due to deflection of attention from the target to the mask. The backward masking deficit in schizophrenia appears to arise from a temporarily stable visual processing impairment in performance within a single test session.

[Alexithymia and automatic activation of emotional-evaluative information]

The emotional valence of stimuli seems to be stored in the associative network and is automatically activated on the mere observation of a stimulus. A principal characteristic of alexithymia represents the difficulty to symbolize emotions verbally. The present study examines the relationship between the dimensions of the alexithymia construct and emotional priming effects in a word-word paradigma. The 20-Item Toronto Alexithymia Scale was administered to 32 subjects along with two word reading tasks as measures of emotional and semantic priming effects. The subscale "difficulty describing feelings" correlated as expected negatively with the negative inhibition effect. The subscale "externally oriented thinking" tended to correlate negatively with the negative facilitation effect. Thus, these dimensions of alexithymia are inversely related to the degree of automatic emotional priming. In summary, there is evidence for an impaired structural integration of emotion and language in persons with difficulties in describing feelings. Poor "symbolization" of emotions in alexithymia is discussed from a cognitive perspective.

[Effectiveness of computer-assisted attention training of schizophrenic patients]

Recent years witnessed a considerable proliferation of computer-based training programmes as instruments of cognitive rehabilitation for schizophrenic patients. A study on the effects of a 3-week computer-based attention training with schizophrenic patients is presented. The Span of Apprehension and the Continuous Performance Test (CTP) were carried out before and after the training period. Performance improvements were found only on few attention training tasks. Schizophrenics had higher post-treatment hit rates on the Span of Apprehension, but no post-treatment improvements were observed in the CPT. Performance of trained patients in the external attention measures was not superior to performance of matched schizophrenic control patients. These data suggest that brief intensive computer-based attention remediation does not lead to enhanced attentional capacity in schizophrenia. Thus, it might be more adequate to teach behavioural strategies that bypass attention deficits or to offer programmes for exercising more complex cognitive skills than to try to remedy basic cognitive impairments.

Differential validity of the Gottschalk-Gleser Anxiety Scales: is gender a moderator variable?

It can be hypothesized that affects like anxiety can be measured by content analysis of speech due to the phenomenon of mood congruent memory, which is found predominantly in females. To assess the effect of gender on the validity of the Gottschalk-Gleser Anxiety Scales, the standard procedure for obtaining verbal samples was followed and self-report measurements of comparable emotional constructs were applied concurrently. Measures of state and trait emotions were administered to 25 female and 25 male university students. In the female group 18 significant convergent validity coefficients were found. For males, content analytic anxiety scores showed four significant correlations with concurrent self-report scales. These results suggest that content analytic anxiety scores from female subjects may allow a more accurate prediction of state and trait emotions than anxiety scores from male subjects. Thus, gender might have a differential effect on the validity of the Gottschalk-Gleser Anxiety Scales.

Relations between neuropsychological vulnerability markers and negative symptoms in schizophrenia

In neuropsychological vulnerability research the visual backward masking task, the Span of Apprehension, the degraded stimulus Continuous Performance Test (dsCPT), and the Wisconsin Card Sorting Test have been described as putative indicators for the predisposition to develop negative (schizophrenic) symptoms. The present study assesses the stability of the association between neuropsychological tests and negative symptoms by examining clinically improved patients. The interdependence between the four cognitive measures and clinical symptomatology was examined in 31 patients with DSM III-R and ICD-10 schizophrenia suffering predominantly from negative symptoms. Backward masking performance was related to affective flattening and anxiety-depression. False alarm rate on dsCPT was associated positively with affective flattening and hallucinations, and negatively with avolition. Card sorting preseverative errors correlated negatively with anhedonia, non-preservative errors correlated positively with avolition. Correlations notwithstanding, the data provide evidence in support of the relative independence of neuropsychological functions and negative symptoms in clinically improved schizophrenics.

Paranoid schizophrenia: non-specificity of neuropsychological vulnerability markers

During stages of remission, patients with paranoid schizophrenia seldom show severe attentional or information-processing dysfunctions, except in cases of long-term chronicity. The diagnostic specificity of four putative psychological vulnerability indicators of schizophrenia - the Span of Apprehension, the degraded stimulus Continuous Performance Test (dsCPT), the degraded stimulus visual backward masking task and the Wisconsin Card Sorting Test (WCST) - was examined in a group of patients with paranoid schizophrenia. Since no single test seems to identify all patients, the use of a combination of measures may be a useful strategy. Accordingly, the four tests were administered to 18 paranoid schizophrenic patients, 18 depressed patients and 18 normal subjects. Paranoid schizophrenic patients could be distinguished from normal subjects primarily on the basis of their performance on the backward masking task and secondarily by the dsCPT and the WCST. Paranoid schizophrenic and depressed patients could be differentiated to some extent by their performance on an information-mask condition of the backward masking task. Thus, of the four measures studied, only the degraded stimulus backward masking appeared to be a specific indicator of paranoid schizophrenia.

[Disorders of early information processing and vigilance as vulnerability markers for schizophrenia]

Disordered processes of scanning iconic memory and vigilance deficits are well-known phenomena in schizophrenics. The "Span of Apprehension" and the "Continuous Performance Test" are among the most important research techniques assessing these impairments and are considered possible neuropsychological vulnerability markers of schizophrenia. Numerous studies compared schizophrenics with psychiatric control groups on these tasks to determine the specificity of the performance deficits which represents a central criterion for vulnerability markers. The review of the empirical results suggests a non-specificity of the performance of schizophrenics on the "Span of Apprehension" and the degraded stimulus version of the Continuous Performance Test. These findings are critically discussed with reference to the technical and methodological characteristics of the studies. Furthermore, studies are presented which examined the relationship of vigilance performance on the Continuous Performance Test and rate of detecting on "Span of Apprehension" and psychopathological symptoms with the aim to evaluate the marker qualities of these research techniques for schizophrenic symptoms. According to the available data a partial symptomatic specificity can be attributed to the "Span of Apprehension".

Gene-splicing experiment

In the article "Windows on a new cosmology" by George Lake (18 May, p. 675), the caption for figure 4(b) on page 680 was incorrect. The photograph shows the electric dipole moment apparatus at the Institute Laue-Langevin in Grenoble, France [courtesy of N. Ramsey].