Additive effects of a family history of schizophrenia spectrum disorders and an environmental risk score for the outcome of patients with non-affective first-episode psychosis.

BACKGROUND: First-episode psychotic disorders comprise a heterogeneous phenotype with a complex etiology involving numerous common small-effect genetic variations and a wide range of environmental exposures. We examined whether a family of schizophrenia spectrum disorder (FH-Sz) interacts with an environmental risk score (ERS-Sz) regarding the outcome of patients with non-affective first episode psychosis (NAFEP). METHODS: We included 288 patients with NAFEP who were evaluated after discharge from an intensive 2-year program. We evaluated three outcome measures: symptomatic remission, psychosocial functioning, and personal recovery. We analyzed the main and joint associations of a FH-Sz and the ERS-Sz on the outcomes by using the relative excess risk due to interaction (RERI) approach. RESULTS: A FH-Sz showed a significant association with poor symptomatic remission and psychosocial functioning outcomes, although there was no significant interaction between a FH-Sz and the ERS-Sz on these outcomes. The ERS-Sz did not show a significant association with poor symptomatic remission and psychosocial functioning outcomes, even though the magnitude of the interaction between ERS-Sz and FH-Sz with the later outcome was moderate (RERI = 6.89, 95% confidence interval -16.03 to 29.81). There was no association between a FH-Sz and the ERS-Sz and personal recovery. CONCLUSIONS: Our results provide further empirical support regarding the contribution of FH-Sz to poor symptomatic remission and poor psychosocial functioning outcomes in patients with NAFEP.

Assessment of cognitive impairment in psychosis spectrum disorders through self-reported and interview-based measures.

Self-reported and interview-based measures can be considered coprimary measures of cognitive performance. We aimed to ascertain to what extent cognitive impairment in psychotic disorders, as assessed with a neuropsychological battery, is associated with subjective cognitive complaints compared to difficulties in daily activities caused by cognitive impairment. We assessed 114 patients who had a psychotic disorder with a set of neuropsychological tests and two additional measures: the Cognitive Assessment Interview-Spanish version (CAI-Sp) and the Frankfurt Complaint Questionnaire (FCQ). Patients also underwent a clinical assessment. The CAI-Sp correlated significantly with all the clinical dimensions, while the FCQ correlated only with positive and depressive symptoms. The CAI-Sp correlated significantly with all cognitive domains, except for verbal memory and social cognition. The FCQ was associated with attention, processing speed and working memory. The combination of manic and depressive symptoms and attention, processing speed, working memory and explained 38-46% of the variance in the patients' CAI-Sp. Education and negative symptoms, in combination with attention, processing speed, and executive functions, explained 54-59% of the CAI-Sp rater's variance. Only negative symptoms explained the variance in the CAI-Sp informant scores (37-42%). Depressive symptoms with attention and working memory explained 15% of the FCQ variance. The ability to detect cognitive impairment with the CAI-Sp and the FCQ opens the possibility to consider these instruments to approximate cognitive impairment in clinical settings due to their ease of application and because they are less time-consuming for clinicians.

Long-term trajectories of clinical staging in first-episode psychosis and their associated cognitive outcome: A 21-year follow-up study.

Cognitive deficits are already present before psychosis onset but are a key feature of first-episode psychosis (FEP). The objective of this study was to investigate the cognitive outcomes of a cohort of FEP patients who were diagnosed using the clinical staging approach and were followed for up to 21 years. We analyzed data from 173 participants with first-admission psychosis who were followed-up for a mean of 20.9 years. The clinical staging assessment was adapted from the clinical staging framework developed by McGorry et al.1 Cognitive assessment was performed using the MATRICS Consensus Cognitive Battery (MMCB) at the end of follow-up. FEP patients who were longitudinally diagnosed in the lowest clinical stages (stages 2A and 2B) showed better performance in attention, processing speed, and MCCB overall composite score than those in the highest clinical stages (stages 4A and 4B). There was a significant linear trend association between worsening of all MCCB cognitive functions and MCCB overall composite score and progression in clinical staging. Furthermore, the interval between two and five years of follow-up appears to be associated with deficits in processing speed as a cognitive marker. Our results support the validation of the clinical staging model over a long-term course of FEP based on neuropsychological performance. A decline in some cognitive functions, such as processing speed, may facilitate the transition of patients to an advanced stage during the critical period of first-episode psychosis.

Lifetime cannabis use and cognition in patients with schizophrenia spectrum disorders and their unaffected siblings.

The relationship between cannabis and cognitive performance is controversial. While both acute administration and long-term cannabis use impair cognitive performance in healthy subjects, several studies have shown improved cognitive outcomes in patients with schizophrenia spectrum disorders who use cannabis. The aim of this study was to determine the relationship between lifetime cannabis use, as assessed longitudinally over 10 years of follow-up in a sample of 42 patients and 35 of their unaffected siblings, and current cognitive performance. Forty-two healthy control subjects were assessed at follow-up with the same instruments. Stepwise linear regression revealed a negative effect of longitudinal cannabis use on performance in a social cognition task in the patient group. In the sibling group, lifetime cannabis use had a negative effect on processing speed and declarative memory performance. In the control group, cannabis use per se did not predict cognitive performance; however, when adding lifetime tobacco use to the model, we found a negative association between lifetime cannabis and tobacco use and processing speed and social cognition performance. Moreover, a lower IQ associated with current cannabis use predicted worse attentional performance in the control group. The differential pattern of associations between cannabis use and cognitive performance in patients compared with siblings and controls can be explained by the negative impact of illness on cognition.

Empirical validation of competing definitions of schizophrenia: a poly-diagnostic study of cognitive impairment in non-affective psychosis.

BACKGROUND: The empirical validation of diagnostic criteria for schizophrenia remains a controversial issue within psychiatry and allied sciences. Most diagnostic criteria are still influenced to a large extent by historical and consensus-based perspectives. METHODS: A poly-diagnostic approach including a set of 23 operationalized diagnostic criteria were administered to probands with non-affective psychosis (n=169). In addition, participants completed a neuropsychological battery during a stable phase of the illness. Attentional, verbal and visual memory and executive functions were assessed. The control group was composed of 26 demographically matched healthy subjects. Analysis of variance was conducted taking neuropsychological performance as response variables and the 23 binary diagnostic systems as explanatory variables. RESULTS: Four out of the 23 operationalized diagnostic systems for schizophrenia (Feighner, French, Kraepelin and Langfeldt criteria) demonstrated high empirical validity for memory and executive functions scores (medium to moderate effect sizes). These 4 systems resemble classic nosological approaches based upon the 'outcome principle' concept, which suggests that schizophrenia leads to deterioration. However, diagnostic effectiveness of neuropsychological tests for the 23 operationalized diagnostic systems of schizophrenia was low (likelihood ratio <2). CONCLUSIONS: Neuropsychological functioning provides empirical validation to operationalized definitions of schizophrenia which are mainly based upon deterioration. It is suggested that some inconsistency of neurobiological studies in schizophrenia might result for using solely current consensus-based diagnostic systems. The implementation of poly-diagnostic strategies could contribute to improve the validity of the schizophrenia construct.

Insight dimensions and cognitive function in psychosis: a longitudinal study.

BACKGROUND: It has been reported that lack of insight is significantly associated with cognitive disturbance in schizophrenia. This study examines the longitudinal relationships between insight dimensions and cognitive performance in psychosis. METHODS: Participants were 75 consecutively admitted inpatients with schizophrenia, affective disorder with psychotic symptoms or schizoaffective disorder. Assessments were conducted at two time points during the study: at the time of hospital discharge after an acute psychotic episode and at a follow-up time that occurred more than 6 months after discharge. A multidimensional approach of insight was chosen and three instruments for its assessment were used: the Scale to Assess Unawareness of Mental Disorder (SUMD), three items concerning insight on the Assessment and Documentation in Psychopathology (AMDP) system and the Insight and Treatment Attitudes Questionnaire. The neuropsychological battery included a wide range of tests that assessed global cognitive function, attention, memory, and executive functions. RESULTS: After conducting adequate statistical correction to avoid Type I bias, insight dimensions and cognitive performance were not found to be significantly associated at cross-sectional and longitudinal assessments. In addition, baseline cognitive performance did not explain changes in insight dimensions at follow-up. Similar results were found in the subset of patients with schizophrenia (n = 37). The possibility of a Type II error might have increased due to sample attrition at follow-up. CONCLUSION: These results suggest that lack of insight dimensions and cognitive functioning may be unrelated phenomena in psychosis.

Dermatoglyphic anomalies and neurocognitive deficits in sibling pairs discordant for schizophrenia spectrum disorders.

The neurodevelopmental hypothesis of schizophrenia suggests that adverse genetic loading in conjunction with environmental factors early in fetal life causes a disruption of neural development, decades before the symptomatic manifestation of the disease. Neurocognitive deficits have been observed early on the course of schizophrenia, and their association with an early developmental brain lesion has been postulated. Dermatoglyphics have been analyzed in schizophrenia as markers of prenatal brain injury because of their early fetal ontogenesis and susceptibility to the same environmental factors that can also affect cerebral development. The aim of our study was to conduct a comparative examination of neurocognitive functions and dermatoglyphic variables in 89 sibling pairs discordant for schizophrenia spectrum disorders. Therefore, we investigated the association between these two markers to explore the prenatal origin of cognitive deficits in schizophrenia. The affected siblings were significantly impaired on all the cognitive variables assessed (Wisconsin Card Sorting Test, Trail Making Test and Continuous Performance Test) and had a greater number of dermatoglyphic anomalies. These results suggest the influence of intrauterine environmental factors in the siblings affected with schizophrenia. However, we did not detect a significant association between these two vulnerability markers in the schizophrenic patients, suggesting the role of genetic or late environmental factors in the origin of the neurocognitive deficits found in these patients.

The association of lifetime insight and cognition in psychosis.

Poor insight has been related to poor course in psychosis. However, the role of cognition in insight remains unclear. The aim of this study was to examine the influence of cognition and lifetime psychopathological dimensions on insight in psychosis. We followed up 42 patients with psychotic disorders over 10years. Lifetime psychopathological dimensions and cognitive performance were assessed. Patients were divided into two groups by lifetime patterns of insight and compared with 42 healthy volunteers. Lower IQ and poorer social cognition were associated with higher risks of poorer lifetime insight of feeling ill and global insight respectively. Lifetime negative symptoms were associated with a higher risk of poorer lifetime insight into symptoms. Lifetime lack of insight is independent of cognitive impairment in specific domains, except for social cognition. Higher IQ may contribute to better lifetime awareness of illness, while better ability to manage emotions is involved in lifetime global insight.

Familial liability to schizophrenia and mood disorders and cognitive impairment in psychosis.

Schizophrenia and other psychoses are complex disorders with high rates of cognitive impairment and a considerable degree of genetic and environmental influence on its etiology. Whether cognitive impairment is related to dimensional scores of familial liability is still matter of debate. We conducted a cross-sectional study including 169 patients with psychotic disorders and 26 healthy controls. Attention, memory and executive functions were assessed, and familial loading scores for schizophrenia and mood disorders were calculated. The relationships between familial liability and neuropsychological performance were examined with Spearman׳s correlation coefficients. In addition, patients were classified into three groups by family loading tertiles, and comparisons were performed between the patients in the top and bottom tertiles. Low familial loading scores for schizophrenia showed a significant association with poor executive functioning and delayed visual memory. And these results were also achieved when the subset of psychotic patients in the two extreme tertiles of family loadings of schizophrenia and mood disorders were compared. Low familial liability to schizophrenia seems to be a contributing factor for the severity of cognitive impairment in patients with a broad putative schizophrenia spectrum diagnosis.

New evidence of association between COMT gene and prefrontal neurocognitive function in healthy individuals from sibling pairs discordant for psychosis.

OBJECTIVE: Using a sample of sibling pairs discordant for psychosis, the authors attempted to replicate the findings of previous studies suggesting that the functional genetic polymorphism Val158Met in the catechol O-methyltransferase (COMT) gene influences prefrontal cognitive function and increases the risk for schizophrenia. METHOD: Eighty-nine sibling pairs discordant for psychosis were genotyped for this polymorphism and were assessed with the Wisconsin Card Sorting Test, a measure of prefrontal function. Additionally, the preferential transmission of alleles for this polymorphism was analyzed in a sample of 89 nuclear families in order to examine the genetic association. RESULTS: In the healthy siblings, a linear relationship was seen in which performance on the Wisconsin Card Sorting Test was associated in an allele dosage fashion with COMT genotype (i.e., fewer perseverative errors with higher number of methionine alleles). However, this association was not observed in patients. Furthermore, no evidence of genetic association with psychosis was detected. CONCLUSIONS: These results seem to confirm the role of COMT genotype in the modulation of executive functions related to frontal lobe function in healthy individuals but not in schizophrenia patients.

Neurological soft-signs in psychosis: threshold criteria for discriminating normal controls and for predicting cognitive impairment.

It is well established that psychotic patients obtain higher scores on neurological soft-sign (NSS) examinations than normal controls, and also that their cognitive performance is poorer. The aims of the present study were to find threshold criteria that distinguish between normal individuals and patients suffering from psychosis, and to investigate the predictive power of NSS for cognitive impairment. The sample was composed of 56 patients suffering from psychosis and 26 normal controls. Neurological assessment was carried out by means of the Neurological Evaluation Scale (NES), and neuropsychological assessment comprised executive, memory, visuospatial abilities, and attention tests. Receiver operating characteristic analysis was used to assess the diagnostic and predictive efficiency of NSS.A total score of 3 or over on the NES scale, or presence of three or more NSS, proved to be good threshold points for defining 'abnormality' in psychosis patients in comparison with normal controls. NSS presented greater predictive power for cognitive impairment than psychopathological dimensions. Moreover, an NES total score of 8 or higher or, to a lesser extent, the presence of six or more NSS in this scale seemed to be valid cut-off points for predicting severe cognitive impairment in individuals with psychosis.NSS were highly efficient predictors of the presence of severe cognitive impairment related to psychosis. However, their ability to discriminate between individuals with psychosis and normal controls was modest.

Executive functioning in schizophrenia spectrum disorder patients and their unaffected siblings: a ten-year follow-up study.

Executive dysfunction represents a core deficit that is associated with schizophrenia spectrum disorders (SSDs). However, the longitudinal course of executive deficits in SSDs is still controversial. The aim of this study was to examine the executive performance of 34 SSD patients in relation to 34 of their unaffected siblings over a period of 10 years. Both groups completed psychopathological and executive assessments. Thirteen healthy controls were assessed using the same instruments. At baseline, the SSD patients differed significantly from siblings and controls in their performance on the Trail Making Test-B (TMT-B) and the number of categories in which they succeeded in the Wisconsin Card Sorting Test (WCST). They also differed significantly from the controls in the total number of errors in the WCST. The siblings did not differ in executive functioning from the controls over the follow-up. Longitudinally, the patients demonstrated significant improvement only for the TMT-B. However, only 14.71% of the patients showed reliable and clinically significant improvements for the TMT-B, and 8.82% made more errors on the WCST at the follow-up evaluation. Less than 3% of the patients showed either improved or worse results on the remaining measures of the WCST. A stabilisation pattern for the WCST was observed in the three groups. The patients performed worse than their siblings and controls on both executive tests. Some patients exhibited significant improvements in the TMT-B over time, but this improvement was reliable and clinically significant for less than 15% of the sample. Thus, we conclude that the patients exhibited stable impairments over time in the executive functions assessed.

The Val66Met polymorphism of the brain-derived neurotrophic factor gene is associated with risk for psychosis: evidence from a family-based association study.

Schizophrenia (SZ) is a prevalent and severe mental disorder. One of the most favored hypotheses for the etiology of SZ is the neurodevelopmental hypothesis. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin growth factor family, promotes the development, regeneration, and survival of neurons and has been linked to the neuropathology of SZ. The present study tested, in a sample of 94 nuclear families, the hypothesis that the BDNF gene Val66Met polymorphism is associated to SZ and its psychopathologic phenotype using a multidimensional symptom approach. Furthermore, considering a reported reduction of BDNF in the frontal cortex of patients with SZ, we studied the relationship between this polymorphism and prefrontal function. The transmission disequilibrium test (TDT) showed a preferential transmission of allele Val from heterozygous parents to the affected offspring (P = 0.002), suggesting a possible role of this gene in the vulnerability to SZ spectrum disorders. The findings remained essentially unchanged when the analysis was restricted to the subgroup of patients with SZ (P = 0.009) and when a multidimensional approach to the diagnosis was used. Quantitative transmission disequilibrium test (QTDT) analyses did not demonstrate a significant association between the prefrontal tests assessed (Wisconsin Card Sorting Test and Trail Making Test) and the transmission of the BDNF alleles. Our finding suggests that the investigated BDNF polymorphism plays an important role in the phenotype of psychosis, but not in the performance of tests of prefrontal cognitive functions analyzed in these patients.