Unirhinal olfactory function in schizophrenia patients and first-degree relatives

Previous studies report birhinal impairments in odor identification in patients with schizophrenia and their family members. The authors employed unirhinal odor identification and detection threshold sensitivity tests in schizophrenia patients, healthy first-degree family members, and healthy comparison subjects. Patients and family members showed deficits in odor identification performance in both nostrils. Odor detection thresholds differed only between patients and healthy comparison subjects. Comparable odor identification deficits in both patients and healthy family members suggest that odor identification measures may serve as a sensitive endophenotypic vulnerability marker and that unirhinal olfactory measures are as precise, if not more so, than birhinal performance measures.     

Emotion processing and theory of mind in schizophrenia patients and their unaffected first-degree relatives

Previous studies have suggested that social cognition is affected in individuals with schizophrenia. The purpose of this study was to explore to what extent social cognition deficits are shared by unaffected first-degree relatives, and the nature of the relationship between performance in different paradigms of social cognition. 20 Schizophrenia patients (7 females, 31 ± 10 years), 20 healthy age- and gender-matched individuals, 20 unaffected first-degree relatives of the schizophrenia patients (11 females, 50 ± 20 years), and 20 healthy individuals matched for age and gender were recruited. Patients showed deficits in the detection of social Faux Pas (0.80 ± 0.17 vs. controls: 0.94 ± 0.09, p = 0.025) and the correct identification of Theory of Mind stories (0.71 ± 0.13 vs. controls: 0.82 ± 0.12, p = 0.038). Relatives performed poorly in the Faces Test (0.83 ± 0.14 vs. controls: 0.9 ± 0.08, p = 0.048), the Reading the Mind in the Eyes Test (0.59 ± 0.17 vs. controls: 0.71 ± 0.14, p = 0.046) and the detection of social Faux Pas (0.8 ± 0.2 vs. controls: 0.93 ± 0.09, p = 0.024). Abnormalities were independent of age, years of education, and general cognitive performance in patients and their relatives. Performance in an Emotion Processing task (Faces Test) was correlated with performance in theory of mind tests in healthy individuals and relatives of patients with schizophrenia only. These results suggest that schizophrenia patients and their unaffected first-degree relatives display similar but nonidentical patterns of social cognition processing.     

Impaired olfactory identification in relatives of patients with familial schizophrenia

OBJECTIVE: Impaired olfactory identification ability has previously been demonstrated in patients with schizophrenia. This study assessed olfactory function in psychotic and nonpsychotic members of multigenerational families with familial schizophrenia to determine whether deficits were present in both groups. METHOD: The University of Pennsylvania Smell Identification Test was administered birhinally to three groups of subjects aged less than 65 years: 19 psychotic and 27 nonpsychotic members of families with familial schizophrenia and 43 age- and sex-matched healthy volunteers. RESULTS: Nonpsychotic family members had significantly higher mean University of Pennsylvania Smell Identification Test scores than psychotic family members but were impaired relative to the healthy volunteer group. These group differences could not be accounted for by age, sex, or smoking habit. Fifty-eight percent of the psychotic and 34% of the nonpsychotic family members performed in the microsmic (impaired) range, compared to 9% of the healthy volunteers. CONCLUSIONS: Impaired olfactory deficits may aggregate in families with schizophrenia and may be indicative of a genetic predisposition to psychosis.     

Low olfactory bulb volume in first-degree relatives of patients with schizophrenia

OBJECTIVE: There is a substantial genetic contribution to schizophrenia but no way to readily identify individuals at risk. Biological abnormalities reflecting greater genetic vulnerability may be discovered by examining healthy family members of patients with schizophrenia. There is evidence that olfactory impairments are common in patients. The authors previously reported that patients have abnormal olfactory bulbs, assessed by magnetic resonance imaging (MRI). This study examined olfactory bulbs in patients' relatives to determine whether low bulb volume represents an endophenotypic marker of genetic vulnerability. METHOD: Olfactory psychophysical measures and MRI scans of olfactory bulbs were acquired from 19 healthy first-degree relatives, 20 healthy comparison subjects with similar age and gender distributions, and the 11 patient probands of these relatives. Olfactory bulb volumes were measured by using a reliable region-of-interest procedure. RESULTS: The patients had impaired ability to detect odors and had lower olfactory bulb volumes than the comparison subjects. Although the family members had normal olfactory ability, they exhibited low right bulb volume. The patients had smaller left, but not right, olfactory bulbs than their own healthy relatives. CONCLUSIONS: The findings in family members suggest that structural abnormalities of the olfactory system in schizophrenia may partly reflect preexisting genetic vulnerability to illness. Preliminary analyses suggest that right olfactory bulb volume may serve as an endophenotypic marker of genetic vulnerability, while left bulb volume may reflect overt disease among individuals who share genetic vulnerability. Bulb abnormalities in patients are consistent with reports of cellular abnormalities affecting peripheral olfactory receptor neurons.     

Neurological signs and psychomotor performance in patients with schizophrenia, their relatives and healthy controls.

Schizophrenic patients (DSM-III-R) were consecutively recruited and 39 were included. Twenty-one were first-episode and 18 were chronic schizophrenic patients. Thirty of the patients were on neuroleptic medication. Thirty-three parents were included, of whom nine were classified as 'family history positive' and 22 as 'family history negative' of a disposition to psychosis. Fifty-five healthy controls volunteered. The subjects were investigated according to a protocol divided into neurological signs and psychomotor performance (finger-tapping rate, Purdue pegboard test, pronation-supination test, gait and hand-grasp strength). Seventy-eight percent of the patients and 7% of the controls were classified as globally aberrant in signs. The patients and their parents, classified as 'family history positive', exhibited a similar laterality pattern in a finger-tapping test improving performance with the preferred hand, significantly different from the performance of the 'family history negative' parents and normal subjects. Duration of illness, neuroleptic medication and negative symptoms were not related to the occurrence of neurological signs and psychomotor performance. These findings indicate that neurological aberrations are present at the onset of illness and that hereditary factors are associated with motor laterality.     

Gastric dysmotility in healthy first-degree relatives of patients with schizophrenia

Gastric dysmotility has been reported in patients suffering from major depression or schizophrenia. An increased sympathetic activity modulating the gastric pacemaker located in the antrum of the stomach has been suggested as the underlying pathology. Similar to patients suffering from schizophrenia, their first-degree relatives showed alterations in cardiac autonomic modulation. Here we aimed to investigate gastric myoelectrical activity in healthy relatives of patients suffering from paranoid schizophrenia.     

The executive control of attention differentiates patients with schizophrenia, their first-degree relatives and healthy controls

Attentional and executive impairments have been reported in patients with schizophrenia and in their healthy first-degree relatives. However, its nature remains unclear and discrepancies between studies have been observed. These might be due to differences in the clinical severity of the illness or in sociodemographic factors. The objective of the present work was to explore the efficiency of three attention networks: alerting, orienting and executive control (conflict inhibition) defined anatomically, using patients, their relatives and controls, assessing the possibility to use them as endophenotypes. We used three tests, the Attention Network Test (ANT), the Wisconsin Card Sorting Test (WCST) and the Stroop Test, and compared 52 patients with schizophrenia, 55 of their first-degree relatives and 53 unrelated healthy controls, taking into account demographic variables (age, sex and years of education) and clinical symptoms of schizophrenia. Patients had a longer overall mean reaction-time (p < 0.001), and took longer to resolve the ANT conflict (ANTc) (p = 0.04) than the control group. In the schizophrenia group, the SSPI disorganization score was significantly correlated to the ANTc performance. Additionally, first-degree relatives of patients with schizophrenia also performed significantly worse than controls in attention performance test. Our findings support a specific deficit in executive control of attention in patients with schizophrenia. This deficit was shown to be correlated with the intensity of the disorganization score in patients. Relative presented an intermediate phenotype between patients and controls; the ANT reaction time (but not the ANTc) may thus be considered as possible endophenotype marker for schizophrenia.     

Recognition memory for faces in schizophrenia patients and their first-degree relatives

It has consistently been shown that schizophrenia patients are impaired in recognition memory for faces. However, studies have not examined the specificity of this deficit relative to other cognitive functions nor the relationship between this deficit and particular schizophrenia symptoms. In addition, no studies have examined recognition memory for faces in unaffected biological relatives of schizophrenia patients who likely share some of the genetic diathesis for this disorder without presenting the potential confounds of mentally ill study samples. The Faces subtests from the Wechsler Memory Scale—Third Edition were used to evaluate recognition memory for faces in 39 schizophrenia patients, 33 of their first-degree relatives and 56 normal controls. Both schizophrenia patients and their relatives were impaired, relative to control participants, in recognition memory for faces after partialing out group differences in spatial attention or verbal memory. Further, recognition memory for faces was associated with positive symptoms in the schizophrenia group and schizotypal personality traits in the relative group. These findings may have important implications for reducing etiological heterogeneity among schizophrenia populations, identifying disorder susceptibility among their relatives and furthering understanding of disorder etiology.     

Neuromuscular and psychomotor abnormalities in patients with schizophrenia and their first-degree relatives

In previous studies of schizophrenic patients, neuromuscular (histopathological and electrophysiological) and psychomotor (finger tapping) abnormalities were found. The present study was designed to investigate relationships between these abnormalities and a family history of psychosis in 14 schizophrenic patients and 25 unaffected first-degree relatives compared to 14 healthy controls. Muscle biopsies were performed in either m. tibialis anterior or m. lateralis. Macro EMG recordings were made from m. tibialis anterior. A finger tapping test was used to investigate psychomotor performance. Neuromuscular abnormalities (muscle biopsies and/or macro EMG) and/or aberrant psychomotor performance (finger tapping test) were found in 13 (93%) patients, 14 (56%) first-degree relatives and in three (21%) controls. A statistically significant relationship for the psychomotor, but not neuromuscular changes to a family history of psychosis was found using a logistic regression method. The percentage of patients, relatives and healthy controls exhibiting were 36/40/7% in the muscle biopsy, 50/20/0% in the macro EMG, and 71/82/14% in the finger tapping investigations. A higher frequency of neuromuscular and psychomotor abnormalities was found in patients with schizophrenia and their first-degree relatives compared to healthy controls. The relationship between psychomotor findings and a family history of psychosis indicate that central aspects of motor aberrations are associated with a hereditary disposition of psychosis. The neuromuscular as well as psychomotor changes indicate that schizophrenia may be a systemic disease involving the central nervous system as well as peripheral organs. An altered cell membrane is suggested to be an underlying factor based on the type of neuromuscular findings.     

Attentional deficits in patients with schizophrenia and in their non-psychotic first-degree relatives

The aim of this study was to investigate whether non-psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs version (CPT-IP) and whether such deficits are associated with negative schizotypal personality disorders. The study subjects were 23 schizophrenic probands, 45 of their first-degree relatives and 36 normal controls. For each subject, attention was assessed during five conditions (2 standard, 2 slow, 1 easy) of visual stimuli (numbers and shapes). Schizotypy status was determined with the physical anhedonia and social anhedonia scales of Chapman et al. (Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. Journal of Abnormal Psychology 42, 374-382). The CPT-IP sensitive index d' in the standard shape condition was significantly lower in schizophrenics and in their relatives than in controls. For all d' values, the percentage of impaired first-degree relatives was at an intermediate level between patients and control individuals. Furthermore, the schizophrenic probands made more random errors in the standard and in the slow number conditions than the other two groups. None of the schizotypy measures correlated with the CPT-IP deficits. These results suggest that spatial sustained attention deficit may be a vulnerability marker for schizophrenia; however, this deficit and the negative dimension of schizotypal personality disorders may be distinct traits.     

Orienting of attention in unmedicated patients with schizophrenia, prodromal subjects and healthy relatives

In typical orienting of attention tasks subjects have to respond as fast as possible to targets which appear in the periphery of the visual field and are preceded by spatial cues (e.g. brightening of a peripheral box where the target may subsequently appear). Reaction times (RT) are facilitated when cue and target appear at the same location (valid cueing) and the cue target interval is short (<250 ms). However, RTs slow down again when the target follows a valid cue after an interval of 250 ms and longer. This latter phenomenon is called Inhibition of Return (IOR) and is thought to reflect an automatic, inhibitory mechanism to protect the organism from redundant and distracting stimuli. Deficits of IOR were repeatedly reported in patients with schizophrenia. However, the role of medications and the nature of the deficit (trait or vulnerability indicator?) were unclear. In the present study we examined 15 unmedicated patients with schizophrenia (age: 31.2+/-11.1, m/f: 11/4, global scores SAPS: 48.33+/-33.09, SANS: 19.22+/-26.16), 29 subjects who were putatively in a prodromal state of psychosis, 30 first-degree relatives, another 8 first-degree relatives who had one child and at least one more relative with schizophrenia, and 50 healthy controls. We found an impairment of IOR only in the unmedicated patient group. In conclusion, blunted IOR in schizophrenia is not secondary to medications. According to this and previous studies blunted IOR may be most probably viewed as a trait cognitive feature of the schizophrenic disorder.     

Antisaccade performance is impaired in medically and psychiatrically healthy biological relatives of schizophrenia patients

Schizophrenia patients and their relatives have been found to exhibit increased reflexive errors on the antisaccade task, suggesting the deficit reflects genetic susceptibility for schizophrenia. To evaluate the degree to which antisaccade error is elevated in schizophrenia relatives, we carried out a meta-analysis of the existing literature and a primary study examining whether the magnitude of reported differences between relative and nonpsychiatric comparison groups could be due to differences in participant inclusion criteria. Meta-analysis yielded a moderate to large effect size across studies comparing relatives and controls (Cohen's d=0.61; Glass' d(g)=0.87). Antisaccade performance in medically and psychiatrically healthy relatives (n=45), who were selected from a larger sample of relatives based on criteria applied to healthy controls, was significantly more impaired than in healthy control participants (d=0.81, d(g)=0.93). Moreover, excluded (n=71) and included relatives did not differ (d=0.14, d(g)=0.13). The results indicate that the antisaccade deficit is a robust phenomenon in unaffected schizophrenia relatives that is not due to differences in inclusion criteria between relatives and controls, and thus are consistent with a growing literature indicating that the antisaccade deficit will be a valuable endophenotype of schizophrenia.     

Neurological soft signs and neurocognitive deficits in remitted patients with schizophrenia,their first-degree unaffected relatives,and healthy controls

European Archives of Psychiatry and Clinical Neuroscience - Neurological soft signs (NSS) and neurocognitive deficits (ND) are highly prevalent in schizophrenia, and have been separately proposed...     

Neural anomalies during sustained attention in first-degree biological relatives of schizophrenia patients.

BACKGROUND: A deficit in sustained attention might serve as an endophenotype for schizophrenia and therefore be a useful tool in understanding the genetic underpinnings of the disorder. We sought to detail functional brain abnormalities associated with sustained attention (i.e., vigilance) in individuals with genetic liability for schizophrenia. METHODS: We gathered electrophysiological data from 23 schizophrenia patients, 28 first-degree biological relatives of schizophrenia patients, and 23 nonpsychiatric control subjects while they performed a degraded-stimulus continuous performance task. Inclusion of sensory control trials allowed separation of target detection and vigilance effects on brain potentials. RESULTS: Schizophrenia patients, but not relatives, showed a behavioral deficit in sustained attention. During target detection, relatives exhibited diminished late positive amplitudes (P3b, i.e., P300) over parietal brain regions and augmented early posterior (P1) and right frontal (anterior N1) potentials. Electrophysiological anomalies were still evident after the exclusion of three relatives with histories of psychosis. CONCLUSIONS: Genetic liability for schizophrenia is associated with augmented early and diminished late brain potentials during sustained attention. Electrophysiological anomalies suggestive of right frontal-posterior parietal dysfunction might represent neural expression of genetic liability for schizophrenia. Electrophysiological indices also seem to be more sensitive than behavioral measures in assessing genetic liability for schizophrenia.     

首发精神分裂症患者及其正常一级亲属血脂和肥胖的研究

目的 研究在排除抗精神病药物影响下精神分裂症患者和其正常一级亲属的脂代谢以及肥胖情况.方法 选择58例符合中国精神障碍分类与诊断标准第三版（CCMD-3）和精神障碍诊断统计手册第四版（DSM-IV）中分裂症诊断标准的首发且未服药的精神分裂症患者（患者组）以及其22例正常一级亲属（亲属组）、24例普通人群（正常对照组）为研究对象,检测腰围、腰臀比、体重指数以及血脂水平（甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇）.结果 患者组的血脂异常发病率为20.7%,高于对照组的,且差异具有显著性（P＜0.05）;而且患者组高密度脂蛋白胆固醇水平（1.31±0.28）mmol/L明显低于对照组的（1.46±0.28）mmol/L,差异亦具有显著性（P＜0.05）,而其他血脂代谢各项指标与对照组相比,都没有显著性差异（P＞0.05）.另外,亲属组的各个指标与对照组相比,均无显著性差异.结论 与普通人群相比,精神分裂症患者具有较高的血脂异常发病率,精神分裂症与脂代谢异常之间存在一定的相关性.     

精神分裂症患者健康一级亲属的认知功能研究

目的：探讨精神分裂症患者健康一级亲属的认知功能特点。方法：对72例精神分裂症患者健康一级亲属（研究组）以及与其人口学资料相匹配的31名健康对照（对照组）进行2-back测验、Go／No．go测验、Stroop测验、修订版韦氏成人智力量表的数字符号、连线测验分量表等认知功能的评定。结果：研究组在2-back测验反应时（t=7．749）和错误数（t=2．432）、Go／No·go测验反应时（t=4．147）以及数字符号测试（t=-2．248）成绩上均差于对照组（P〈0．05或P〈0．001）。多发病家系组在2-back测验反应时（t=3．233）、Go／No-go测验反应时（t=2．981）以及数字符号测试（t=2．041）成绩上均差于单发病家系组（P〈0．05或P〈0．01）。结论：精神分裂症患者健康一级亲属存在不同程度的认知功能损害;认知功能损害可能是精神分裂症的遗传易感性指标。     

Longitudinal MRI study in schizophrenia patients and their healthy siblings

To investigate whether genetic and/or disease-related factors are involved in progressive structural brain changes in schizophrenia, magnetic resonance imaging scans with a 5-year scan interval were acquired in patients, their same-gender siblings and matched healthy controls. Structural equation modelling was applied to assess disease and familial effects. Whole brain and cerebral grey matter volumes decreased excessively in patients compared with their siblings and the controls, suggesting that the progressive brain loss in schizophrenia may be related to the disease process.     

精神分裂症患者及其一级亲属性格特征的对照研究

目的探讨精神分裂症患者及其一级亲属的性格特征。方法选取住我院治疗处于缓解期的精神分裂症患者48例和一级亲属与正常组各79人，进行MMPI测查分析。结果精神分裂症患者及其一级亲属Hs、D、Hy、Pd、Pa、Pt、Sc量表分高于正常人，而患者和一级亲属间各量表分接近。结论精神分裂症患者及一级亲属具有明显的分裂性人格，两者的性格特征可能有着共同的遗传学基础。