Neurological signs and the heterogeneity of schizophrenia

Neurological soft signs in first episode psychosis among psychiatric hospital patients and its relationship with dimensions of psychopathology: A comparative study

Background

Neurological soft signs (NSS), as subtle, nonlocalising neurological abnormalities, are considered as the potential markers of psychosis. However, comparative studies of antipsychotic-naïve patients with first-episode psychosis (FEP) and first degree relatives (FDRs) are uncommon. We compared the prevalence and pattern of NSS in FEPs, their healthy FDRs and a healthy non-relatives' control group (HC), highlighted the relationship between NSS and psychopathology and proposed cut-off scores for prevalence studies.

Materials and Methods

Two hundred and two participants per group were recruited. The FEPs were consecutive attendees; FDRs were accompanying caregivers; while the HC were from hospital staff. The Brief Psychiatric Rating Scale and the Neurological Evaluation Scale were used to assess psychopathology dimensions and NSS, respectively.

Results

Using an item score of two ('substantial impairment'), the prevalence of at least one NSS was: 91.5% (95% confidence interval [CI]: 86.7%-94.9%), 16.8% (95% CI: 11.8%-22.7%) and 6.5% (95% CI: 3.5%-10.9%), respectively, for FEP, FDRs and HC. FEPs were impaired in a broad range of signs. The noteworthy relationships were as follows: (i) a significant correlation between the negative symptoms' dimension versus number of NSS (r = 0.4), and NSS total score (r = 0.3), (ii) the anxiety/depression dimension correlated negatively with number of NSS (r = -0.3) and (iii) NSS cut across psychosis categories. We propose a cut-off score of ≥ 4 for the number of signs signifying probable impairment.

Conclusion

The findings indicate that, subject to further studies, NSS could be regarded as a broader phenotype of neurologic dysfunction associated with psychosis proness.

Copy Number Variations and Schizophrenia

Schizophrenia is a neurodevelopmental disorder with genetic and environmental factors involved in its aetiology. Genetic liability contributing to the development of schizophrenia is a subject of extensive research activity, as reliable data regarding its aetiology would enable the improvement of its therapy and the development of new methods of treatment. A multitude of studies in this field focus on genetic variants, such as copy number variations (CNVs) or single-nucleotide variants (SNVs). Certain genetic disorders caused by CNVs including 22q11.2 microdeletion syndrome, Burnside-Butler syndrome (15q11.2 BP1-BP2 microdeletion) or 1q21.1 microduplication/microdeletion syndrome are associated with a higher risk of developing schizophrenia. In this article, we provide a unifying framework linking these CNVs and their associated genetic disorders with schizophrenia and its various neural and behavioural abnormalities.

Neurological soft signs are increased in major depressive disorder irrespective of treatment

The significance of neurological soft signs (NSS) in major depressive disorder (MDD) remains unclear and the stability of NSS in relation to antidepressant treatment has never been investigated. We hypothesized that NSS are relatively stable trait markers of MDD. We thus predicted that patients show more NSS than healthy controls, irrespective of illness duration and antidepressant treatment. To test this hypothesis, NSS were assessed in chronically depressed, medicated MDD patients before (n = 23) and after (n = 18) a series of electroconvulsive therapy (ECT). In addition, NSS were assessed once in acutely depressed, unmedicated MDD patients (n = 16) and healthy controls (n = 20). We found that both chronically depressed, medicated MDD patients and acutely depressed, unmedicated MDD patients showed more NSS than healthy controls. The degree of NSS in both patient groups did not differ. Importantly, we found no change in NSS after on average eleven sessions of ECT. Thus, the manifestation of NSS in MDD seems to be independent of illness duration and pharmacological and electroconvulsive antidepressant treatment. From a clinical perspective, our findings corroborate the neurological safety of ECT.

Overexpression of transmembrane TNFα in brain endothelial cells induces schizophrenia-relevant behaviors

Upregulation of genes and coexpression networks related to immune function and inflammation have been repeatedly reported in the brain of individuals with schizophrenia. However, a causal relationship between the abnormal immune/inflammation-related gene expression and schizophrenia has not been determined. We conducted co-expression networks using publicly available RNA-seq data from prefrontal cortex (PFC) and hippocampus (HP) of 64 individuals with schizophrenia and 64 unaffected controls from the SMRI tissue collections. We identified proinflammatory cytokine, transmembrane tumor necrosis factor-α (tmTNFα), as a potential regulator in the module of co-expressed genes that we find related to the immune/inflammation response in endothelial cells (ECs) and/or microglia of the brain of individuals with schizophrenia. The immune/inflammation-related modules associated with schizophrenia and the TNF signaling pathway that regulate the network were replicated in an independent cohort of brain samples from 68 individuals with schizophrenia and 135 unaffected controls. To investigate the association between the overexpression of tmTNFα in brain ECs and schizophrenia-like behaviors, we induced short-term overexpression of the uncleavable form of (uc)-tmTNFα in ECs of mouse brain for 7 weeks. We found schizophrenia-relevant behavioral deficits in these mice, including cognitive impairment, abnormal sensorimotor gating, and sensitization to methamphetamine (METH) induced locomotor activity and METH-induced neurotransmitter levels. These uc-tmTNFα effects were mediated by TNF receptor2 (TNFR2) and induced activation of TNFR2 signaling in astrocytes and neurons. A neuronal module including neurotransmitter signaling pathways was down-regulated in the brain of mice by the short-term overexpression of the gene, while an immune/inflammation-related module was up-regulated in the brain of mice after long-term expression of 22 weeks. Our results indicate that tmTNFα may play a direct role in regulating neurotransmitter signaling pathways that contribute to the clinical features of schizophrenia.

Neurological Soft Signs (NSS) in Census-Based, Decade-Adjusted Healthy Adults, 20 to >70 Years of Age

Neurological soft signs (NSS) represent minor neurological features and have been widely studied in psychiatric disease. The assessment is easily performed. Quantity and quality may provide useful information concerning the disease course. Mostly, NSS scores differ significantly between patients and controls. However, literature does not give reference values. In this pilot study, we recruited 120 healthy women and men to build a cross-sectional, census-based sample of healthy individuals, aged 20 to >70 years, subdivided in 10-year blocks for a close approach to the human lifeline. Testing for NSS and neurocognitive functioning was performed following the exclusion of mental and severe physical illness. NSS scores increased significantly between ages 50+ and 60+, which was primarily accountable to motor signs. Gender and cognitive functioning were not related to changes of scores. Although the number of individuals is small, study results may lay a foundation for further validation of NSS in healthy individuals.

Independent vector analysis for common subspace analysis: Application to multi-subject fMRI data yields meaningful subgroups of schizophrenia

The extraction of common and distinct biomedical signatures among different populations allows for a more detailed study of the group-specific as well as distinct information of different populations. A number of subspace analysis algorithms have been developed and successfully applied to data fusion, however they are limited to joint analysis of only a couple of datasets. Since subspace analysis is very promising for analysis of multi-subject medical imaging data as well, we focus on this problem and propose a new method based on independent vector analysis (IVA) for common subspace extraction (IVA-CS) for multi-subject data analysis. IVA-CS leverages the strength of IVA in identification of a complete subspace structure across multiple datasets along with an efficient solution that uses only second-order statistics. We propose a subset analysis approach within IVA-CS to mitigate issues in estimation in IVA due to high dimensionality, both in terms of components estimated and the number of datasets. We introduce a scheme to determine a desirable size for the subset that is high enough to exploit the dependence across datasets and is not affected by the high dimensionality issue. We demonstrate the success of IVA-CS in extracting complex subset structures and apply the method to analysis of functional magnetic resonance imaging data from 179 subjects and show that it successfully identifies shared and complementary brain patterns from patients with schizophrenia (SZ) and healthy controls group. Two components with linked resting-state networks are identified to be unique to the SZ group providing evidence of functional dysconnectivity. IVA-CS also identifies subgroups of SZs that show significant differences in terms of their brain networks and clinical symptoms.

Shared co-expression networks in frontal cortex of the normal aged brain and schizophrenia

Previous studies on the brain of people with schizophrenia have identified structural changes and gene expression changes, suggesting that brain aging maybe accelerated in people with schizophrenia. To better characterize gene expression profiles in schizophrenia and in the aged population we constructed co-expression networks using RNA-Seq data from frontal cortex. The first data set analysed was from 62 subjects with schizophrenia and 51 unaffected controls ranging in age from 19 to 63 years. The second separate data set was from normal control individuals ranging in age from 29 to 106 years. In the first data set, we found two co-expression modules significantly associated with schizophrenia. One was a downregulated co-expression module enriched for neuron function related genes and the other was an upregulated immune/inflammation-related module. In the second data set of normal individuals, we found seven co-expression modules significantly correlated with age. A comparison of the co-expression modules from the two data sets revealed a significant consensus in nodes associated with schizophrenia and those associated with normal aging. The results indicate that a co-expression module related to neuronal function is downregulated and an immune/inflammation related co-expression module is upregulated, and associated with cells of the blood vessels, in both schizophrenia and in normal aging. This finding adds further support to the hypothesis that there may be accelerated brain aging in schizophrenia.

Association between neurological soft signs and antioxidant enzyme activity in schizophrenic patients

To determine the relationship between alterations in the activity of the enzymes participating in antioxidative defense system and neurological soft signs (NSS) in schizophrenic patients with the first episode psychosis (S_FE, n = 19), patients in relapse (S_R, n = 46), and healthy controls (HC, n = 20). NSS intensity and enzymatic plasma activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were compared between S_FE, S_R and HC subjects and a follow-up correlation analyses between the enzyme activities and NSS intensity was performed. NSS intensity was increased four times in schizophrenic patients compared with healthy controls. Activities of SOD and CAT were 40% decreased in S_FE and these reductions were ameliorated by antipsychotic treatment. GPX activity was 20% decreased in both patient groups compared with controls. A negative correlation between NSS intensity and GPX activity was specifically found in the S_FE patients. The data in this report argue that a reduction of GPX activity might be one of the causes for the emergence of NSS at the onset of schizophrenia, and provide the evidence that antipsychotic therapy can attenuate activity reductions of SOD and CAT, but not the activity reduction of GPX and the intensity of NSS.

Neurological Soft Signs in Schizophrenia: An Update on the State- versus Trait-Perspective

BACKGROUND

Neurological soft signs (NSS) represent minor neurological signs, which indicate non-specific cerebral dysfunction. In schizophrenia, their presence has been documented extensively across all stages of the disease. Until recently, NSS were considered an endophenotype or a trait phenomenon. During the past years, however, researchers report fluctuations of the NSS scores.

AIMS

To further clarify the question whether NSS exhibit state or trait components or both, studies that have investigated NSS longitudinally were reviewed.

METHOD

Studies which have assessed NSS longitudinally in adults suffering from schizophrenia, were searched for. The time frame was January 1966 to June 2017. Studies on teenagers were excluded because of interferences between brain maturation and pathology.

RESULTS

Twenty-nine follow-up studies were identified. They included patients during different stages of their illness and mainly used established instruments for NSS assessment. Patients with a first episode or a remitting course predominantly show a decrease of NSS over time, whereas a worsening of NSS can be found in the chronically ill. It was shown that change of NSS total scores over time is predominantly caused by motor system subscales and to a lesser extent by sensory integration scales. With respect to medication, the majority of studies agree on a relationship between medication response and improvement of NSS while the type of antipsychotic does not seem to play a major role. Moreover, where information on side-effects is given, it does not favor a strong relationship with NSS. However, NSS seem to correlate with negative and cognitive symptoms.

CONCLUSION

Studies manifest a conformity regarding the presence of NSS in schizophrenia patients on the one hand. On the other hand, fluctuations of NSS scores have been widely described in subgroups. Taken together results strongly support a state-trait dichotomy of NSS. Thus, the usage of NSS as an endophenotype has to be called into question.

Clinical significance of neurological abnormalities in psychosis

The neurological deficits in sensory and motor function in schizophrenia have been described using a confusing variety of terms, reflecting their uncertain relevance and significance to psychosis. In this article we explore the nature of neurological abnormalities in psychosis, describe their assessment and suggest their potential relevance for clinician and patient. We propose that the assessment of neurological abnormalities and extrapyramidal side-effects should figure in the assessment of any patient with psychosis, particularly at illness onset. Furthermore, we suggest that neurological abnormalities can inform prognostic predictions and help to identify patients with more complex future care needs.

Primary and persistent negative symptoms: Concepts, assessments and neurobiological bases

Primary and persistent negative symptoms (PPNS) represent an unmet need in the care of people with schizophrenia. They have an unfavourable impact on real-life functioning and do not respond to available treatments. Underlying etiopathogenetic mechanisms of PPNS are still unknown. The presence of primary and enduring negative symptoms characterizes deficit schizophrenia (DS), proposed as a separate disease entity with respect to non-deficit schizophrenia (NDS). More recently, to reduce the heterogeneity of negative symptoms by using criteria easily applicable in the context of clinical trials, the concept of persistent negative symptoms (PNS) was developed. Both PNS and DS constructs include enduring negative symptoms (at least 6months for PNS and 12months for DS) that do not respond to available treatments. PNS exclude secondary negative symptoms based on a cross-sectional evaluation of severity thresholds on commonly used rating scales for positive symptoms, depression and extrapyramidal side effects; the DS diagnosis, instead, excludes all potential sources of secondary negative symptoms based on a clinical longitudinal assessment. In this paper we review the evolution of concepts and assessment modalities relevant to PPNS, data on prevalence of DS and PNS, as well as studies on clinical, neuropsychological, brain imaging electrophysiological and psychosocial functioning aspects of DS and PNS.

Psychiatric symptoms mediate the effects of neurological soft signs on functional outcomes in patients with chronic schizophrenia: A longitudinal path-analytic study

Neurological soft signs (NSS) in motor coordination and sequencing occur in schizophrenia patients and are an intrinsic sign of the underlying neural dysfunctions. The present longitudinal study explored the relationships among NSS, psychiatric symptoms, and functional outcomes in 151 Chinese patients with chronic schizophrenia across a 6-month period. The participants completed neurological assessments at baseline (Time 1), psychiatric interviews at Time 1 and 3-month follow-up (Time 2), and self-report measures on daily functioning at 6-month follow-up (Time 3). Two possible (combined and cascading) path models were examined on predicting the functional outcomes. Direct and indirect effects of Time 1 NSS on Time 3 functional outcomes via Time 2 psychiatric symptoms were evaluated using path analysis under bootstrapping. Motor coordination and sequencing NSS did not have significant direct effects on functional outcomes. Motor coordination NSS exerted significant and negative indirect effects on functional outcomes via psychiatric symptoms. These results contribute to a better understanding of the determinants of functional outcomes by showing significant indirect pathways from motor coordination NSS to functional outcomes via psychiatric symptoms. That motor sequencing NSS did not affect functional outcomes either directly or indirectly may be explained by their trait marking features.

Neurological soft signs: Effects of trait schizotypy, psychological distress and auditory hallucination predisposition

Schizotypy is regarded as a trait vulnerability for psychotic disorders, yet alone is insufficient for development of a diagnosable disorder. Additional symptoms and psychological distress are necessary for help seeking and transition from an at risk mental state to a clinical diagnosis. The present study investigated the interaction between trait schizotypy, state auditory verbal hallucination (AVH) predisposition, distress and handedness for the expression of neurological soft signs (NSS), a neurodevelopmental vulnerability factor for psychosis. Cluster analysis formed schizotypy groups statistically across the dimensions captured by the SPQ. It was hypothesized that schizotypy and AVH predisposition would interact, resulting in significantly greater NSS. Psychological distress and handedness were hypothesized to be significant covariates, accounting for some variance in the expression of NSS between the groups. A sample of University students (n = 327) completed the Schizotypal Personality Questionnaire, Launay-Slade Hallucination Scale, General Health Questionnaire and the Neurological Evaluation Scale (NES). Cluster Analysis revealed four schizotypy groups. Distress was not a significant covariate in any analysis. As expected, those with high overall schizotypy and high AVH predisposition expressed significantly greater Motor-Coordination NSS compared to those with high schizotypy and low AVH predisposition. Within the Mixed Interpersonal and Cognitive-Perceptual Schizotypy cluster, those with low AVH predisposition expressed significantly more Motor-Coordination NSS than those with high AVH predisposition. These findings suggest motor coordination NSS are detectable in schizotypy, and AVH predisposition appears to interact with these traits. This study highlights the importance of considering both trait and subclinical state risk factors when investigating risk for psychosis.

Neurobiology of insight deficits in schizophrenia: An fMRI study

Prior research has shown insight deficits in schizophrenia to be associated with specific neuroimaging changes (primarily structural) especially in the prefrontal sub-regions. However, little is known about the functional correlates of impaired insight. Seventeen patients with schizophrenia (mean age 40.0±10.3; M/F=14/3) underwent fMRI on a Philips 3.0 T Achieva system while performing on a self-awareness task containing self- vs. other-directed sentence stimuli. SPM5 was used to process the imaging data. Preprocessing consisted of realignment, coregistration, and normalization, and smoothing. A regression analysis was used to examine the relationship between brain activation in response to self-directed versus other-directed sentence stimuli and average scores on behavioral measures of awareness of symptoms and attribution of symptoms to the illness from Scale to Assess Unawareness of Mental Disorders. Family Wise Error correction was employed in the fMRI analysis. Average scores on awareness of symptoms (1=aware; 5=unaware) were associated with activation of multiple brain regions, including prefrontal, parietal and limbic areas as well as basal ganglia. However, average scores on correct attribution of symptoms (1=attribute; 5=misattribute) were associated with relatively more localized activation of prefrontal cortex and basal ganglia. These findings suggest that unawareness and misattribution of symptoms may have different neurobiological basis in schizophrenia. While symptom unawareness may be a function of a more complex brain network, symptom misattribution may be mediated by specific brain regions.

Are Negative Symptoms Dimensional or Categorical? Detection and Validation of Deficit Schizophrenia With Taxometric and Latent Variable Mixture Models

Studies have supported the validity of the deficit form of schizophrenia (ie, people with primary and enduring negative symptoms). A test of whether that group is a true taxon-that is, a distinct, discontinuous group-has yet to be conducted and the underlying structure of negative symptoms as categorical or dimensional remains undetermined. The present study examined the latent structure of negative and deficit symptoms to determine if a nonarbitrary boundary distinguishes deficit from nondeficit forms of schizophrenia (ie, whether these symptoms reflect a continuous or categorical variable). Schedule for the Deficit Syndrome ratings of 789 individuals with a psychotic disorder were submitted to taxometric and latent variable mixture analyses to test categorical vs dimensional hypotheses of negative symptoms and deficit schizophrenia. Analytic models favored a taxonic structure of negative symptoms and the validity of the deficit/nondeficit classification scheme. Taxometric classification outperformed clinician-based deficit/nondeficit classification in its association with summer birth, male sex, premorbid adjustment, neurocognition, and psychosocial functioning. Within taxon and complement classes, severity scores remained significant predictors of premorbid adjustment, neurocognition, and psychosocial functioning. Thus, although a categorical approach is validated, a hybrid categorical-dimensional conceptualization of negative symptoms also has validity for the prediction of external variables.

Schizophrenia: a systemic disorder

The concept of schizophrenia that is most widely taught is that it is a disorder in which psychotic symptoms are the main problem, and a dysregulation of dopamine signaling is the main feature of pathophysiology. However, this concept limits clinical assessment, the treatments offered to patients, research, and the development of therapeutics. A more appropriate conceptual model is that: 1) schizophrenia is not a psychotic disorder, but a disorder of essentially every brain function in which psychosis is present; 2) it is not a brain disease, but a disorder with impairments throughout the body; 3) for many patients, neuropsychiatric problems other than psychosis contribute more to impairment in function and quality of life than does psychosis; and, 4) some conditions that are considered to be comorbid are integral parts of the illness. In conclusion, students, patients, and family members should be taught this model, along with its implications for assessment, research, and therapeutics.

The ratios of 2nd to 4th digit may be a predictor of schizophrenia in male patients

The production of androgens (mostly testosterone) during the early fetal stage is essential for the differentiation of the male brain. Some authors have suggested a relationship between androgen exposure during the prenatal period and schizophrenia. These two separate relationships suggest that digit length ratios are associated with schizophrenia in males. The study was performed in a university hospital between October 2012 and May 2013. One hundred and three male patients diagnosed with schizophrenia according to DSM-IV using SCID-I, and 100 matched healthy males, were admitted to the study. Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms (SANS) and Brief Psychiatric Rating Scale (BPRS) were used to assess schizophrenia symptoms. The second digit (2D) and fourth digit (4D) asymmetry index (AI), and the right- and left-hand 2D:4D ratios were calculated. All parametric data in the groups were compared using an independent t-test. The predictive power of the AI was estimated by receiver operating characteristics analysis. The 2D:4D AI was statistically significantly lower in the patient group than the healthy control comparison group. There were significant differences between the schizophrenia and the control groups in respect of left 2D:4D and right 2D:4D. There was no correlation between AI, left, or right 2D:4D, BPRS, or SAPS in the schizophrenia group. However, there was a negative correlation between left 2nd digit (L2D):4D and the SANS score. Our findings support the view that the 2D:4D AI can be used as a moderate indicator of schizophrenia. Even more simply, the right or left 2D:4D can be used as an indicator. L2D:4D could indicate the severity of negative symptoms.

Neurological soft signs might be endophenotype candidates for patients with deficit syndrome schizophrenia

BACKGROUND

Schizophrenia is a chronic, disabling, disorder that affects approximately 1% of the population. The nature of schizophrenia is heterogeneous, and unsuccessful efforts to subtype this disorder have been made. Deficit syndrome schizophrenia (DS) is a clinical diagnosis that has not been placed in main diagnostic manuals. In this study, we aimed to investigate and compare neurological soft signs (NSS) in DS patients, non-deficit schizophrenia (NDS) patients, and healthy controls (HCs). We suggest that NSS might be an endophenotype candidate for DS patients.

METHODS

Sixty-six patients with schizophrenia and 30 HCs were enrolled in accordance with our inclusion and exclusion criteria. The patients were sub-typed as DS (n=24) and NDS (n=42) according to the Schedule for the Deficit Syndrome. The three groups were compared in terms of sociodemographic and clinical variables and total scores and subscores on the Physical and Neurological Examination for Soft Signs (PANESS). Following the comparison, a regression analysis was performed for predictability of total PANESS score and its subscales in the diagnosis of DS and NDS.

RESULTS

The groups were similar in terms of age, sex, and smoking status. The results of our study indicated that the total PANESS score was significantly higher in the DS group compared to the NDS and HC groups, and all PANESS subscales were significantly higher in the DS group than in the HC group. The diagnosis of DS was predicted significantly by total PANESS score (P<0.001, odds ratio =9.48, 95% confidence interval: 0.00-4.56); the synergy, graphesthesia, stereognosis, motor tasks, and ability to maintain posture subscales were found to be significant predictors.

CONCLUSION

This study confirms that NSS were higher in patients with DS. In addition, we suggest that our results might support the notion of DS as a different and distinct type of schizophrenia. NSS might also be a promising candidate as an endophenotype for DS. However, large sampled, multicentric studies are needed to clarify the place of NSS as an endophenotype in DS.

Correlation of neurological soft signs and neurocognitive performance in first episode psychosis

Neurological soft signs and neurocognitive impairments are commonly observed in first episode psychosis but the correlation of these factors remains controversial. Here, we evaluated 30 patients with remitted first episode psychosis and 30 healthy controls for the presence and severity of neurological soft signs (using the Neurological Evaluation Scale--NES) and for neurocognitive impairments (using seven subtests of the Cambridge Neuropsychological Test Automated Battery--CANTAB). NES score was higher in patients compared to controls. Neurocognitive impairment was evident in patients in the following domains: working memory, spatial recognition memory, attention set shifting, planning and inhibition. The NES revealed significant correlations with spatial working memory performance and Intra-Extra Dimensional Set Shifting (as a component of executive function). These correlations were observed both in patients and in controls. Planning and inhibition showed correlation with the total NES score and the sequencing of complex motor acts in both groups. In addition, spatial span and spatial recognition memory showed significant correlation with total NES score and the sequencing of complex motor acts in controls. The correlation between sequencing of complex motor acts and specific domains of neurocognitive tasks suggests that similar neuroanatomical substrates might be implicated in these processes.

Neurological abnormalities in recent-onset schizophrenia and asperger-syndrome

BACKGROUND

Neurological abnormalities including a variety of subtle deficits such as discrete impairments in sensory integration, motor coordination (MOCO), and sequencing of complex motor acts are frequently found in patients with schizophrenia (SZ) and commonly referred to as neurological soft signs (NSS). Asperger-syndrome (AS) is characterized by sensory-motor difficulties as well. However, the question whether the two disorders share a common or a disease-specific pattern of NSS remains unresolved.

METHOD

A total of 78 age- and education-matched participants [26 patients with recent-onset SZ, 26 individuals with AS, and 26 healthy controls (HC)] were recruited for the study. Analyses of covariance (ANCOVAs), with age, years of education, and medication included as covariates, were used to examine group differences on total NSS and the five subscale scores. Discriminant analyses were employed to identify the NSS subscales that maximally discriminate between the three groups.

RESULTS

Significant differences among the three groups were found in NSS total score and on the five NSS subscales. The clinical groups differed significantly in the NSS subscale MOCO. The correct discriminant rate between patients with SZ and individuals with AS was 61.5%. The correct discriminant rate was 92.3% between individuals with AS and HC, and 80.8% between SZ patients and HC, respectively.

CONCLUSION

Our findings provide new evidence for the presence of NSS in AS and lend further support to previously reported difficulties in movement control in this disorder. According to the present results, SZ and AS seem to be characterized by both quantitative and qualitative NSS expression.

Progress in the study of negative symptoms

A selective review of the negative symptoms of schizophrenia is an appropriate article to result from the festschrift honoring William T. Carpenter Jr, as he has made substantial contributions in this area. This review assesses progress in 3 areas in which he has been an important investigator: the distinction between primary vs secondary negative symptoms; the appropriate design for treatment trials; and the nosology of negative symptoms.

Characterization of the deficit syndrome in drug-naive schizophrenia patients: the role of spontaneous movement disorders and neurological soft signs

This study aimed to characterize the deficit syndrome in drug-naive schizophrenia patients and to examine the relationship between deficit features and primary neurological abnormalities. Drug-naive schizophrenia patients (n = 102) were examined at baseline for demographics, premorbid functioning, duration of untreated illness (DUI), psychopathology, neurological signs, and deficit symptoms, and reassessed at 1-year follow-up. Neurological abnormalities were examined before inception of antipsychotic medication and included four domains of spontaneous movement disorders (SMD) and four domains of neurological soft signs (NSS). Patients fulfilling the deficit syndrome criteria at the two assessments (n = 20) were compared with nondeficit patients (n = 82) across demographic, clinical, and neurological variables. Deficit and nondeficit groups showed similar demographic characteristics and levels of psychotic, disorganization, and depressive symptoms. Compared with nondeficit patients, deficit patients showed poorer premorbid adjustment, higher premorbid deterioration, a lengthier DUI, and much poorer functional outcome. Relative to the nondeficit patients, those with the deficit syndrome showed higher levels of SMD--excepting akathisia--and NSS. This association pattern was also evident for deficit and neurological ratings in the whole sample of schizophrenia patients. Parkinsonism, motor sequencing, and release signs were all independently related to the deficit syndrome. These findings confirm that the deficit/nondeficit categorization is replicable and reliable in first-admission patients and raise the possibility that premorbid deterioration, deficit symptoms, and neurological abnormalities represent a triad of manifestations that share common underlying neurobiological mechanisms. More specifically, the data are consistent with a neurodevelopmental model of deficit symptoms involving basal ganglia dysfunction.

Histone methylation at H3K9: evidence for a restrictive epigenome in schizophrenia

OBJECTIVE

Epigenetic changes are stable and long-lasting chromatin modifications that regulate genomewide and local gene activity. The addition of two methyl groups to the 9th lysine of histone 3 (H3K9me2) by histone methyltransferases (HMT) leads to a restrictive chromatin state, and thus reduced levels of gene transcription. Given the numerous reports of transcriptional down-regulation of candidate genes in schizophrenia, we tested the hypothesis that this illness can be characterized by a restrictive epigenome.

METHODS

We obtained parietal cortical samples from the Stanley Foundation Neuropathology Consortium and lymphocyte samples from the University of Illinois at Chicago (UIC). In both tissues we measured mRNA expression of HMTs GLP, SETDB1 and G9a via real-time RT-PCR and H3K9me2 levels via western blot. Clinical rating scales were obtained from the UIC cohort.

RESULTS

A diagnosis of schizophrenia is a significant predictor for increased GLP, SETDB1 mRNA expression and H3K9me2 levels in both postmortem brain and lymphocyte samples. G9a mRNA is significantly increased in the UIC lymphocyte samples as well. Increased HMT mRNA expression is associated with worsening of specific symptoms, longer durations of illness and a family history of schizophrenia.

CONCLUSIONS

These data support the hypothesis of a restrictive epigenome in schizophrenia, and may associate with symptoms that are notoriously treatment resistant. The histone methyltransferases measured here are potential future therapeutic targets for small molecule pharmacology, and better patient prognosis.

Dynamics of neurological soft signs and its relationship to clinical course in patients with first-episode schizophrenia

The aim of the study was to assess the dynamics of neurological soft signs (NSS) over four years from the clinical onset of schizophrenia, depending on the clinical course of the disease, and to evaluate the relationship of NSS to symptomatic dimensions in patients with first-episode schizophrenia. Sixty-eight patients with first-episode schizophrenia were included in the trial. The clinical status was assessed using Positive and Negative Syndrome Scale (PANSS) at the same time as the neurological examination, at admission to the hospital for first-episode schizophrenia and at a check-up examination four years later. The assessment of NSS using the Neurological Evaluation Scale (NES) coincided with the assessment of the clinical condition of the patients. According to the Andreasen remission criterion of schizophrenia, after four years we found that 57% of patients' were remitters and 43% were non-remitters. During the monitoring period, in remitters total NES score and sensory integration/sequencing of motor acts items of the NES decreased. In non-remitters, increase in the total NES score and the 'others' item of the NES was observed. A connection between the dynamics of NSS and the clinical course of schizophrenia, over the period of four years, and a relationship between NSS and negative schizophrenia symptoms was found.

Neurological soft signs and psychometrically identified schizotypy in a sample of young conscripts

There is growing interest in the connection between neurological soft signs (NSS) and schizophrenia spectrum disorders such as schizotypal personality disorder. The association between NSS and schizotypy was investigated in a subgroup of 169 young healthy male military conscripts included in the Athens Study of Psychosis Proneness and Incidence of Schizophrenia. During their first 2 weeks in the National Basic Air Force Training Centre (T(1)-first assessment), subjects completed the Schizotypal Personality Questionnaire (SPQ), the Symptom Checklist-90-Revised (SCL-90-R), and the Raven's Progressive Matrices (RPM). Then, 2 years later (T(2)-second assessment), at the time of military discharge, they were tested for NSS with the Neurological Evaluation Scale (NES) and reevaluated with the SPQ, the SCL-90-R and additionally the Structured Clinical Interview for Personality Disorders (SCID-II) for the Diagnostic and Statistical Manual of Mental Disorders Third Edition, Revised (DSM-III-R). NSS were more prominent in conscripts with high schizotypy; scores on Sequencing of Complex Motor Acts (SCMA) and the "Other Soft Signs" (OSS) subscales were correlated with high schizotypy at both T(1) and T(2). Increased levels of SCMA as well as the total NSS score were correlated at both T(1) and T(2) with the interpersonal SPQ factor (reflecting negative schizotypy). The findings support the proposal that negative schizotypy might be associated with subtle neurodevelopmental abnormalities.

Finding behavioral and network indicators of brain vulnerability

Resilience research has usually focused on identifying protective factors associated with specific stress conditions (e.g., war, trauma) or psychopathologies (e.g., post-traumatic stress disorder [PTSD]). Implicit in this research is the concept that resilience is a global construct, invariant to the unfavorable circumstances or the psychopathologies that may develop (i.e., the mechanisms underlying the resilience of an individual in all cases are expected to be similar). Here we contribute to the understanding of resilience—and its counterpart, vulnerability—by employing an approach that makes use of this invariant quality. We outline two main characteristics that we would expect from indicators of a vulnerable state: that they should appear across disorders regardless of specific circumstances, and that they should appear much before the disorder is evident. Next, we identify two sets of factors that exhibit this pattern of association with psychopathological states. The first was a set of “low-level” sensory, motor and regulatory irregularities that have been reported across the clinical literature; we suggest that these can serve as behavioral indicators of a vulnerable state. The second was the set of aberrations in network metrics that have been reported in the field of systems neuroscience; we suggest that these can serve as network indicators of a vulnerable state. Finally, we explore how behavioral indicators may be related to network indicators and discuss the clinical and research-related implications of our work.

Neurological soft signs in schizophrenia - The past, the present and the future

Clinical neurological abnormalities in patients with schizophrenia have been generally called "Neurological Soft Signs" (NSS). Studies have consistently shown increased NSS in patients with schizophrenia as compared to healthy persons. Early studies were limited by possible confounds of prior neuroleptic medications and illness chronicity. Studies in first episode never treated schizophrenia patients have addressed these confounds. The clinical significance of these findings and the correlation with cognitive dysmetria is the focus of the current review. Relevant literature was obtained using PUBMED and MEDLINE search (1980-2008) and a direct search of reference list of pertinent journal articles. In a 2003 study, neuroleptic-naive schizophrenia patients had significantly more NSS than controls. Patients who were more neurologically impaired had more negative symptoms. Higher NSS scores in treatment-naive schizophrenia patients and the absence of correlation between NSS and illness duration lends support to a neurodevelopmental pathogenesis for schizophrenia. The finding of incoordination and cerebellar signs in most studies also supports the "cognitive dysmetria" explanatory model for schizophrenia. A significant subgroup of patients with schizophrenia may have more neuropathological abnormalities, which predisposes them for a more severe and chronic course of illness. These patients may potentially be identified by clinical neurological examination, which might be very important for prognostication and evolving better methods of treatment for these patients. NSS, by themselves or as a composite index with other neurobiological parameters, hold potential as a candidate endophenotype for schizophrenia.

Minor physical anomalies and neurological soft signs in patients with schizophrenia and their siblings

Neurological soft signs (NSSs) and minor physical anomalies (MPAs) are consistently found at higher rates in individuals with schizophrenia compared to healthy controls. However, limited research has been conducted on these traits among the biological relatives of these patients. We aimed to identify the possible origins of these traits in schizophrenia by exploring them in patients with schizophrenia, their healthy siblings and normal controls. Ninety-six patients with schizophrenia, their 66 non-psychotic siblings and 52 healthy subjects were studied. Measures included the Neurological Evaluation Scale, a structured examination for detection of minor physical anomalies, stroop and verbal fluency tests for cognitive assessment, and scales for assessment of disease severity in patients; the Scale for the Assesment of Negative Symptoms and the Scale for the Assesment of Positive Symptoms. Increased rates of NSSs and high MPA scores were found in both the patients and their siblings as compared to normal controls. MPAs in several body regions were similar (eyes, ears, hands and feet) or correlated (innercanthal width and head circumference) between patients and their respective siblings. However, there was little similarity in palate and tongue anomalies between these subjects. These results suggest that NSSs and MPAs might represent two distinct markers of risk for schizophrenia. MPAs at different locations may also represent distinct pathological processes, such that palate and tongue abnormalities are more likely to represent non-familial rather than familial factors compared to other abnormalities.

Risk factors, pre-morbid functioning and episode correlates of neurological soft signs in drug-naive patients with schizophrenia-spectrum disorders

BACKGROUND

There is a lack of consistent evidence regarding associations of neurological soft signs (NSS) with illness-related variables in schizophrenia. This study examined NSS in first-episode psychotic patients with respect to their factor structure and associations with risk factors, pre-morbid characteristics, psychopathology and spontaneous extrapyramidal syndromes.

METHOD

First-episode, drug-naive patients with schizophrenia-spectrum disorders (n=177) were assessed for NSS using the Neurological Evaluation Scale, and its 26 constituting items were factor analysed. The identified neurological dimensions were then entered into hierarchical regression models as outcome dependent variables of a set of predictors including risk factors (familial loading for schizophrenia, obstetric complications), pre-morbid characteristics (neurodevelopmental delay, symptoms of attention deficit-hyperactivity disorder, pre-morbid functioning), psychopathological domains (reality distortion, disorganization, negative symptoms, mania, depression, catatonia) and spontaneous extrapyramidal syndromes (parkinsonism, dyskinesia, akathisia).

RESULTS

Five neurological domains were identified: sequencing, release signs, sensory integration, abnormal movements and coordination. Multivariate analyses showed independent associations (p<0.01) of sequencing with familial liability to schizophrenia, deterioration of pre-morbid adjustment and parkinsonism; release signs with obstetric complications, catatonic symptoms and parkinsonism; sensory integration with familial liability to schizophrenia; abnormal movements with familial liability to schizophrenia, obstetric complications, parkinsonism and dyskinesia; and coordination with neurodevelopmental delay. The empirically derived factors explained additional variance over and above that explained by subscale scores across the examined variables.

CONCLUSIONS

Familial liability to schizophrenia, obstetric complications, neurodevelopmental delay, deterioration in pre-morbid functioning and observable motor disorders appear to contribute independently to domains of neurological dysfunction. The findings support a neurodevelopmental model of NSS in schizophrenia.

Impaired insight in patients with newly diagnosed nonaffective psychotic disorders with and without deficit features

Patients with schizophrenia who have primary, enduring negative symptoms, or the deficit syndrome, have poorer psychosocial functioning but lesser clinical distress compared with nondeficit patients. Poor awareness of impairment in patients with deficit schizophrenia may contribute to this seeming contradiction. We hypothesized that poor insight would be present early in the course of illness in deficit patients, and that those with deficit features would have greater impairment in insight than those without deficit features. One-hundred one first-episode patients with nonaffective psychotic disorders were categorized into deficit (n=31) and nondeficit (n=70) groups. The deficit patients had significantly poorer insight than nondeficit patients when rated using a self-report questionnaire, and nearly significantly poorer insight rated by clinical researchers. Further, this effect remained for self-rated insight and reached statistical significance for researcher-rated insight after controlling for positive, negative, and general psychopathology symptoms. These results suggest that the treatment of deficit patients may be particularly complicated by poor insight.

Neurobiological susbtrates in deficit and non deficit schizophrenia

The deficit syndrome defines a subgroup of schizophrenia patients with prominent and enduring primary negative symptoms (1). Behavioral, structural, and functional neuroimaging studies have implicated mainly the dorsolateral prefrontal - thalamocortical circuit. Deficit syndrome patients seem to have larger ventricles in MRI studies (2). Neurological soft signs suggest parietal involvement with greater sensory integration impairment in deficit syndrome patients (3). On the contrary, some biological markers such as P50 gating have not shown any difference between deficit and non-deficit schizophrenia (4). Finally, no pharmacological treatment has so far proven effective for the treatment of primary enduring negative symptoms (5). In conclusion, deficit pathology in schizophrenia seems to involve the prefrontal and parietal lobes and have different neurobiological substrates than positive symptoms.

The diagnostic concept of schizophrenia: its history, evolution, and future prospects

More than a century since the delineation of dementia praecox by Kraepelin, the etiology, neuropathology and pathophysiology of schizophrenia remain elusive. Despite the availability of criteria allowing reliable diagnostic identification, schizophrenia essentially remains a broad clinical syndrome defined by reported subjective experiences (symptoms), loss of function (behavioral impairments), and variable patterns of course. Research has identified a number of putative biological markers associated with the disorder, including neurocognitive dysfunction, brain dysmorphology, and neurochemical abnormalities. Yet none of these variables has to date been definitively proven to possess the sensitivity and specificity expected of a diagnostic test. Genetic linkage and association studies have targeted multiple candidate loci and genes, but failed to demonstrate that any specif ic gene variant, or a combination of genes, is either necessary or sufficient to cause schizophrenia. Thus, the existence of a specific brain disease underlying schizophrenia remains a hypothesis. Against a background of an ever-increasing volume of research data, the inconclusiveness of the search for causes of the disorder fuels doubts about the validity of the schizophrenia construct as presently defined. Given the protean nature of the symptoms of schizophrenia and the poor coherence of the clinical and biological findings, such doubts are not without reason. However, simply dismantling the concept is unlikely to result in an alternative model that would account for the host of clinical phenomena and research data consistent with a disease hypothesis of schizophrenia. For the time being, the clinical concept of schizophrenia is supported by empirical evidence that its multiple facets form a broad syndrome with non-negligible internal cohesion and a characteristic evolution over time. The dissection of the syndrome with the aid of endophenotypes is beginning to be perceived as a promising approach in schizophrenia genetics.

Neurological soft signs in schizophrenia: a meta-analysis

BACKGROUND

Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups.

METHOD

A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms.

RESULTS

A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%-10% of their variance with NSS.

CONCLUSIONS

NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness.

P50 gating in deficit and nondeficit schizophrenia

Dysfunctional auditory sensory processing has generally been found in schizophrenia and it has been suggested that these deficits might be related to clinical and psychosocial variables. The present study included P50 recordings using a simple-paired click auditory evoked potential paradigm in sixty patients with deficit schizophrenia (DS), sixty patients with nondeficit schizophrenia (NDS), and sixty comparison subjects. The Schedule for the Deficit Syndrome was used to categorize patients as DS or NDS. The two patient groups did not differ in clinical variables, except for higher negative dimension and lower community outcome scores in DS than in NDS patients. There were no differences in P50 ratios between deficit and nondeficit subgroups; compared with normal subjects both groups of schizophrenia patients showed impaired P50 ratios (p<0.0001). This ratio appears to be independent of positive and negative symptoms. However, impairment in P50 gating correlated with poorer community outcome. The data document the existence of early auditory sensory processing abnormalities in DS and NDS, and might suggest that common neuronal network abnormalities underlie both forms of schizophrenia. Deficient P50 gating may be associated with impaired functional outcome in schizophrenia.

The psychiatric symptomatology of deficit schizophrenia: a meta-analysis

A relatively large literature has emerged supporting the notion that the deficit syndrome reflects a distinct illness within schizophrenia. One topic that has received limited attention is how deficit schizophrenia differs from nondeficit schizophrenia in terms of psychiatric symptomatology. The present study conducted a meta-analysis of 47 published studies to compare deficit and nondeficit patients in severity of positive, disorganization, negative, mood and total psychiatric symptoms. The patient groups did not differ in terms of positive or total psychiatric symptoms but deficit patients showed less severe mood symptoms and slightly more severe disorganization symptoms. Not surprisingly, deficit patients had much more severe negative symptoms. These results are discussed in terms of the construct validity of the deficit syndrome and the larger heterogeneity of schizophrenia. Additionally, diagnostic issues regarding the deficit syndrome are considered.

Genetics and intermediate phenotypes of the schizophrenia--bipolar disorder boundary

Categorization of psychotic illnesses into schizophrenic and affective psychoses remains an ongoing controversy. Although Kraepelinian subtyping of psychosis was historically beneficial, modern genetic and neurophysiological studies do not support dichotomous conceptualization of psychosis. Evidence suggests that schizophrenia and bipolar disorder rather present a clinical continuum with partially overlapping symptom dimensions, neurophysiology, genetics and treatment responses. Recent large scale genetic studies have produced inconsistent findings and exposed an urgent need for re-thinking phenomenology-based approach in psychiatric research. Epidemiological, linkage and molecular genetic studies, as well as studies in intermediate phenotypes (neurocognitive, neurophysiological and anatomical imaging) in schizophrenia and bipolar disorders are reviewed in order to support a dimensional conceptualization of psychosis. Overlapping and unique genetic and intermediate phenotypic signatures of the two psychoses are comprehensively recapitulated. Alternative strategies which may be implicated into genetic research are discussed.

Neurological disorders in schizophrenia

Schizophrenia (SZ) is a complex, heterogeneous, and disabling psychiatric disorder that impairs multiple aspects of human cognitive, perceptual, emotional, and behavioral functioning. SZ is relatively frequent (prevalence around 1%), with onset usually during adolescence or early adulthood, and has a deteriorating course. The rapidly growing area of neuroimaging research has has found clear evidence of many cortical and subcortical abnormalities in individuals with SZ. In this article the most recent findings from multiple studies on neurological disorders in SZ are reviewed, and the authors make a strong argument for a neurological basis of the schizophrenic process.

Combining dimensional and categorical representation of psychosis: the way forward for DSM-V and ICD-11?

BACKGROUND

There is good evidence that psychotic symptoms segregate into symptom dimensions. However, it is still unclear how these dimensions are associated with risk indicators and other clinical variables, and whether they have advantages over categorical diagnosis in clinical practice. We investigated symptom dimensions in a first-onset psychosis sample and examined their associations with risk indicators and clinical variables. We then examined the relationship of categorical diagnoses to the same variables.

METHOD

We recruited 536 patients as part of a population-based, incidence study of psychosis. Psychopathology was assessed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). A principal axis factor analysis was performed on symptom scores. The relationship of dimension scores with risk indicators and with clinical variables was then examined employing regression analyses. Finally, regression models were compared to assess the contribution of dimensions versus diagnosis in explaining these variables.

RESULTS

Factor analysis gave rise to a five-factor solution of manic, reality distortion, negative, depressive and disorganization symptom dimensions. The scores of identified dimensions were differentially associated with specific variables. The manic dimension had the highest number of significant associations; strong correlations were observed with shorter duration of untreated psychosis, acute mode of onset and compulsory admission. Adding dimensional scores to diagnostic categories significantly increased the amount of variability explained in predicting these variables; the reverse was also true but to a lesser extent.

CONCLUSIONS

Categorical and dimensional representations of psychosis are complementary. Using both appears to be a promising strategy in conceptualising psychotic illnesses.

Deficit schizophrenia: an overview of clinical, biological and treatment aspects

The concept of deficit schizophrenia is regarded as one of the most promising attempts to reduce heterogeneity within schizophrenia. This paper summarizes the clinical, neurocognitive, brain imaging and electrophysiological correlates of this subtype of schizophrenia. Attempts to identify genetic and non-genetic risk factors are reviewed. Methodological limitations of studies supporting the efficacy of atypical antipsychotics in the treatment of the syndrome are highlighted. Two decades of research on deficit schizophrenia have failed to prove that it represents the extreme end of a severity continuum in schizophrenia, while some findings support the claim that it may be a separate disease entity.

Neurological soft signs in patients with schizophrenia and their unaffected siblings: frequency and correlates in two ethnic and socioeconomic distinct populations

Recent studies have suggested that ethnicity and socioeconomic status may have an impact on the frequency and significance of neurological soft signs (NSS). However, this impact has not been adequately assessed. The objectives were to determine the NSS scores in patients with schizophrenia and their unaffected siblings and to examine the clinical and therapeutic correlates of NSS in two ethnic and socioeconomic distinct populations. Two independent replicate studies were carried out: (1) a French Caucasian sample of 69 patients with schizophrenia, 43 of their unaffected siblings and 108 control subjects; (2) a Tunisian sample of 66 patients with schizophrenia, 31 of their unaffected siblings and 60 control subjects. NSS were assessed with a multidimensional scale, previously validated in drug-naïve and treated samples of patients with schizophrenia. Both patient groups were assessed with the positive and negative syndrome scale (PANSS), the clinical global impressions (CGI) and the global assessment of functioning. NSS total scores were significantly higher in patients with schizophrenia comparatively to siblings and to controls in both studies. The two sibling groups had also higher NSS scores than controls. In addition, NSS total scores were correlated to the PANSS negative and disorganization sub-scores, to the CGI-severity of illness and to a low educational level in both studies. These studies provide a confirmation in two distinct samples of the high prevalence of NSS in patients with schizophrenia, and in their biological relatives, independently of their respective ethnic and socioeconomic origins.

Potential Endophenotype for Schizophrenia: Neurological Soft Signs

Introduction: Neurological soft signs (NSS) are suggested as a candidate endophenotype for schizophrenia. This article aims to review relevant literature and discuss the role of NSS in understanding schizophrenia. Methods: This is an update on a review article published in 2003. Articles from 2003 onwards were specifically reviewed and discussed with relevance to the role of NSS as endophenotype for schizophrenia. Results: Consistent data suggest an excess of NSS in schizophrenic patients. NSS appear to be related to schizophrenic symptoms, in particular negative symptoms and disorganisation. Information on NSS and demographic correlates is scarce, and the confounding effects between age, education and intelligence on NSS constitute an important gap in current knowledge. Longitudinal data suggest NSS as both a trait and state variable in the course of disease. NSS are not specific with regard to diagnosis, although there are claims that individual sub-components may be more specific. The weight of evidence raises question on the specificity of NSS for schizophrenia. Conclusions: The usefulness and feasibility of NSS as a specific endophenotype target for schizophrenia is unclear. However, NSS remain an important feature and symptom correlate of schizophrenia. Future research should focus on delineating the effects of NSS from those of confounding demographic variables, and the stability of NSS over the course of illness to elucidate its role in schizophrenia. Key words: Diagnostic specificity, Neurological examination abnormalities, Psychotic symptoms, Review, Trait

Neurological abnormalities among offspring of persons with schizophrenia: relation to premorbid psychopathology

BACKGROUND

Neurological Examination Abnormalities (NEA, often called "neurological soft signs") have been observed in early schizophrenia and may be heritable. We investigated the prevalence, and neurocognitive and psychopathological correlates of NEA among offspring of schizophrenia patients who are at increased genetic risk for this illness.

METHODS

Neurological examinations were conducted on high risk (HR, n=74) and healthy comparison subjects (HS, n=86), using the Heinrichs-Buchanan scale. Cognitive-perceptual (CogPer) and repetitive motor (RepMot) subscores, and total NEA scores were computed. All HR and HS were assessed using K-SADS/SCID for diagnoses. Schizotypy was measured using the Magical Ideation and the Perceptual Aberration subscales (Chapman scale), attention using Continuous Performance Test (CPT-IP) and executive functions using the Wisconsin Card Sorting Test (WCST).

RESULTS

CogPer (F(1,160)=7.14, p=0.008) but not RepMot NEA scores were higher in HR subjects compared to HS after controlling for age and sex. CogPer NEA scores were higher in HR subjects with axis I psychopathology compared to those without (F(2,170)-6.41, p=0.002). HR subjects had higher schizotypy scores (composite of the magical ideation and perceptual aberration scales) (F(1,141)=23.25, p=0.000004). Schizotypy scores were negatively correlated with sustained attention and executive functions. In addition, schizotypy was positively correlated with CogPer NEA scores.

CONCLUSIONS

Young relatives at increased genetic risk for schizophrenia show more frequent NEA. CogPer but not RepMot NEA scores were elevated, consistent with our prior observation of CogPer NEA being relatively specific for schizophrenia. The observed relationships between NEA, cognitive impairments, schizotypy and axis I disorders suggest that NEA may characterize a subgroup of HR offspring at an elevated risk for psychopathology.

Fewer neurological soft signs among first episode psychosis patients with heavy cannabis use

BACKGROUND

Although neurological soft signs (NSS) have been consistently associated with schizophrenia and a variety of risk factors, few studies have focused on the association between NSS and environmental factors such as cannabis use, particularly in patients with first episode psychosis.

METHODS

We administered the Neurological Evaluation Scale (NES) to 92 patients during their first episode of functional psychosis. Psychopathology was assessed with the Positive And Negative Syndrome Scale (PANSS) and the family history of psychotic disorder was established on the basis of the Family Interview for Genetic Studies (FIGS). We also assessed lifetime cannabis and cocaine use utilizing that specific section of the Composite International Diagnostic Interview. The outcome variable was the presence of high NSS, defined by a score above the median split of the NES score (>21).

RESULTS

Most patients (80/92, 87%) presented a non-affective psychosis. The presence of high NSS showed a significant independent association with not having been a heavy cannabis user (OR=8.3; 95% CI, 2.4-33.3), family history of psychosis (OR=4.3; 95% CI, 1.2-14.9), male sex (OR=4.0; 95% CI, 1.2-14.0), lower score in verbal fluency and higher score in negative symptoms (both p<0.01).

CONCLUSION

Our cross-sectional results support the hypothesis that potentially different pathways associated with the emergence of first episode psychosis may exist, including neurological premorbid alteration and environmental cannabis abuse.

Remission in patients with first-episode schizophrenia receiving assured antipsychotic medication: a study with risperidone long-acting injection

Recently proposed criteria for remission by a 'Remission in Schizophrenia Working Group' have generated considerable interest. We assessed rates, predictors, and correlates of remission in a sample of patients with first-episode schizophrenia treated with injectable, long-acting risperidone. This allowed us to examine remission among patients known to be receiving medication. This was a single-site open-label study in which 50 newly diagnosed cases of schizophreniform disorder or schizophrenia aged 16 to 43 years were treated with injectable, long-acting risperidone 25-50 mg every 2 weeks for 2 years. Remission, according to Remission in Schizophrenia Working Group criteria, was achieved in 64% of the patients. Of those achieving remission, 97% maintained this status until study completion. Remission was associated with greater improvements in other symptom domains, insight, and social and occupational functioning. Patients in remission received lower doses of antipsychotic medication, had fewer extrapyramidal symptoms, and a more favorable attitude toward medication. The results of this open-label study suggest that a majority of first-episode patients who receive long-acting injectable antipsychotic medication may achieve sustained remission. Double-blind-controlled studies using long-acting injectable antipsychotics in early psychosis are warranted to further test this.

Deficit schizophrenia: an update

The criteria for deficit schizophrenia were designed to define a group of patients with enduring, primary (or idiopathic) negative symptoms. In 2001, a review of the literature suggested that deficit schizophrenia constitutes a disease separate from nondeficit forms of schizophrenia. Here we provide a review of new studies, not included in that paper, in which patients with deficit schizophrenia and those with nondeficit schizophrenia were compared on dimensions typically used to distinguish diseases: signs and symptoms, course of illness, pathophysiological correlates, risk and etiological factors, and treatment response. Replicated findings and new evidence of double dissociation supporting the separate disease hypothesis are highlighted. Weaknesses in research and treatment options for these patients are also emphasized.