Cognitive Function In Schizophrenia Research Articles

Utility of the UCSD Performance-based Skills Assessment-Brief Japanese version: discriminative ability and relation to neurocognition

The UCSD Performance-based Skills Assessment Brief (the UPSA-B) has been widely used for evaluating functional capacity in patients with schizophrenia. The utility of the battery in a wide range of cultural contexts has been of concern among developers. The current study investigated the validity of the Japanese version of the UPSA-B as a measure of functional capacity and as a co-primary for neurocognion. Sixty-four Japanese patients with schizophrenia and 83 healthy adults entered the study. The Japanese version of the UPSA-B (UPSA-B Japanese version) and the MATRICS Cognitive Consensus Battery Japanese version (MCCB Japanese version) were administered. Normal controls performed significantly better than patients, with large effect sizes for the Total and the subscale scores of the UPSA-B. Receiver Operating Characteristic (ROC) curve analysis revealed that the optimal cut-off point for the UPSA-B Total score was estimated at around 80. The UPSA-B Total score was significantly correlated with the MCCB Composite score and several domain scores, indicating the relationship between this co-primary measure and overall cognitive functioning in Japanese patients with schizophrenia. The results obtained here suggest that the UPSA-B Japanese version is an effective tool for evaluating disturbances of daily-living skills linked to cognitive functioning in schizophrenia, providing an identifiable cut-off point and relationships to neurocognition. Further research is warranted to evaluate the psychometrical properties and response to treatment of the Japanese version of the UPSA-B.

Antibodies to Toxoplasma gondii and cognitive functioning in schizophrenia, bipolar disorder, and nonpsychiatric controls.

Increased rates of exposure to Toxoplasma gondii have been found in individuals with schizophrenia and bipolar disorder, but the association between Toxoplasma and cognitive functioning has not previously been examined. We measured IgG and IgM class antibodies to Toxoplasma in 408 nonelderly individuals with schizophrenia, 347 with bipolar disorder, and 352 nonpsychiatric controls. Cognitive functioning was measured with the Repeatable Battery for the Assessment of Neuropsychological Status. Multivariate linear and regression analyses showed significant associations between Toxoplasma IgM antibody level and cognitive scores within the control group and the bipolar disorder group but not the schizophrenia group. Within the control group, having an elevated Toxoplasma IgM antibody level, greater than or equal to the 50th and 75th levels of the control group, was associated with significantly elevated odds of a low total cognitive score. Exposure to Toxoplasma may confer risk for lower cognitive functioning in persons without a psychiatric disorder and those with bipolar disorder.

Distress intolerance and clinical functioning in persons with schizophrenia

Impaired tolerance to distress may help explain part of the cognitive and functional impairments in schizophrenia (SZ). This project investigated distress intolerance in SZ patients as compared to controls, and whether distress intolerance represented an independent domain in relationship to symptoms, cognition, and functional capacity. Healthy controls (n=43) and SZ (n=65) completed a psychological distress challenge experiment and their levels of intolerance to distress were estimated. SZ showed increased distress intolerance such that they were significantly more likely to terminate the distress challenge session early compared to controls. Greater distress intolerance was associated with reduced functional capacity and worse cognitive performance in SZ. Mediation analyses suggested that distress intolerance had an independent effect on functional capacity, while some of this effect was mediated by cognitive performance. Our results suggest that distress intolerance is a promising domain for treatment research, and functional capacity may be improved by targeting treatments towards SZ patient׳s ability to tolerate distress.

Antipsychotic-induced parkinsonism is associated with working memory deficits in schizophrenia-spectrum disorders.

In view of the significant cognitive deficits in schizophrenia and their impact on patients' social and occupational functioning, and considering that the influence potential influence of antipsychotic-induced extrapyramidal symptoms on cognition in schizophrenia remains poorly understood, the current study sought to identify the clinical, socio-demographic and neurologic predictors of the cognitive performance of schizophrenia patients. Eighty-two schizophrenia-spectrum (DSM-IV criteria) outpatients were recruited. Psychiatric symptoms were evaluated with the Positive And Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Extrapyramidal symptoms were evaluated with the Extrapyramidal Symptoms Rating Scale, while spatial working, planning abilities and visual paired associates learning were evaluated with the CAmbridge Neuropsychological Tests Automated Battery. The Stroop test was also administered. Multivariate hierarchic linear regression analyses were performed. We found that negative symptoms were associated with cognitive flexibility, planning, visual learning and working memory performance in schizophrenia. Age, sex, number of hospitalizations and antipsychotic type also emerged as significant predictors. More importantly, we found a significant association between antipsychotic-induced parkinsonism and working memory performance. The fact that negative symptoms and socio-demographic variables predicted cognitive performance in schizophrenia is consistent with the previous literature on the topic. The finding of an association between parkinsonism and working memory may have clinical implications, since working memory deficits are considered putative endophenotypes of schizophrenia and are known to impair patients' social and occupational functioning. Our results will need to be replicated in longitudinal studies involving larger samples of patients.

A longitudinal study of cognitive functioning in schizophrenia: Clinical and biological predictors

BackgroundCognitive deficits are a central feature of schizophrenia but it is not certain how cognitive functioning changes over time. The purpose of this prospective longitudinal study was to determine the temporal change of cognitive functioning and the predictors of cognitive performance from among demographic, clinical, and biological variables. MethodsParticipants were individuals with schizophrenia or schizoaffective disorder whose cognitive functioning was assessed at multiple time points with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). At the baseline visit participants had a blood sample drawn from which C-reactive protein, antibodies to Herpes Simplex Virus type 1, and selected genetic polymorphisms were measured. Repeated measures linear regression was used to determine whether cognitive measures changed over time and which variables predicted cognitive performance. ResultsThe sample consisted of 132 participants, mean age 43.7years at baseline, who received a median of 3 cognitive assessments over a period averaging 2.8years. The RBANS Total score and Language index showed no statistically significant temporal change; performance on two indices, Immediate Memory and Attention, showed modest but statistically significant improvements (gains of 0.89±0.33 and 0.76±0.29 points per year, respectively); Visuospatial/Constructional performance showed a modest but statistically significant decline (of 0.80±0.25 points per year). Few variables predicted cognitive performance; however greater psychiatric symptom severity was associated with worse cognitive performance for most cognitive measures. ConclusionsCognitive functioning in middle-aged persons with schizophrenia showed an absence of decline for most measures and modest gains in some measures.

Exploring effects of EAAT polymorphisms on cognitive functions in schizophrenia.

To evaluate the effect of functional polymorphisms (rs4354668 and rs2731880) of the excitatory amino acid transporters (EAAT1 and 2) on the cognitive dysfunction that characterizes schizophrenia. One hundred and ninety two subjects diagnosed with schizophrenia were assessed with Brief Assessment of Cognition in Schizophrenia, Wisconsin Card Sorting Test, Continuous Performance Test and N-back test and genotyped for rs4354668 and rs2731880. ANOVA showed a significant difference among both EAAT1 and EAAT2 genotype groups on different cognitive measures. Worse performances were observed among carriers of the genotypes associated with lower EAAT expression. RESULTS suggest that impaired activity and EAAT expression could influence cognitive performances in schizophrenia, thus representing a target of interest for development of pharmacological strategies aimed to improve cognition.

Protocol to evaluate the impact of yoga supplementation on cognitive function in schizophrenia: a randomised controlled trial.

Schizophrenia (SZ) is a chronic illness that is treated symptomatically. Cognitive dysfunction is a core feature of SZ that is relatively intractable to pharmacotherapy. Yoga can improve cognitive function among healthy individuals. A recent open trial indicated significant benefits of yoga training (YT) in conjunction with conventional pharmacotherapy among patients with SZ. To describe the protocol for an ongoing randomised controlled trial designed to test whether the reported beneficial effects of YT on cognitive function among SZ patients can be replicated. Secondarily, the effects of YT on daily functioning living skills are evaluated. Consenting patients with SZ receive routine clinical treatment and are randomised to adjunctive YT, adjunctive physical exercise (PE) or treatment as usual (proposed N = 234 total, N = 78 in each group). The trial involves YT or PE 5 days a week and lasts 3 weeks. Participants are evaluated thrice over 6 months. Cognitive functions measured by Trail Making Test, University of Pennsylvania Neurocognitive Computerised Battery were primary outcome measures while clinical severity and daily functioning measured by Independent Living Skills Survey were secondary outcome measures. A total of 309 participants have been randomised as of 31 August 2013, which exceeded beyond 294 proposed after attrition. Once participants begin YT or PE they generally complete the protocol. No injuries have been reported. Short term YT is feasible and acceptable to Indian SZ patients. If beneficial effects of YT are detected, it will provide a novel adjunctive cognitive remediation strategy for SZ patients.

Comparing cognitive functioning in schizophrenia and autism using WAIS-III

The main goal of this study was to investigate differences and similarities in general cognitive functioning between adults with schizophrenia and autism, because this has not been systematically investigated. We used a cross-sectional design to compare adults with schizophrenia (n=27), with autism (n=114) and a healthy control group (n=30). Schizophrenia diagnoses were based on the Structured Clinical Interview for the DSM-IV Axis I (SCID-I) and behavioral symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Autism was diagnosed with a DSM-IV questionnaire for autism spectrum disorders and the Autistic Diagnostic Interview, revised version. The Wechsler Adult Intelligence Scale, third version (WAIS-III) was used to assess cognitive functions. All participants were between 18 and 65 years of age and had a minimum full scale intelligence of 80. Results showed that patients with schizophrenia scored significantly lower on processing speed than patients with autism and the healthy control group. Differences on other index scales were not found. In participants with schizophrenia a correlation was found between processing speed impairment and negative symptoms. Diagnosis could be predicted correctly with WAIS-III profile in 70.4% of the cases with schizophrenia compared to 56.7% of the healthy control group and 22.8% of the autism group.

Mismatch negativity latency and cognitive function in schizophrenia.

BackgroundThe Mismatch Negativity (MMN) is an event-related potential (ERP) sensitive to early auditory deviance detection and has been shown to be reduced in schizophrenia patients. Moreover, MMN amplitude reduction to duration deviant tones was found to be related to functional outcomes particularly, to neuropsychological (working memory and verbal domains) and psychosocial measures. While MMN amplitude is thought to be correlated with deficits of early sensory processing, the functional significance of MMN latency remains unclear so far. The present study focused on the investigation of MMN in relation to neuropsychological function in schizophrenia.MethodForty schizophrenia patients and 16 healthy controls underwent a passive oddball paradigm (2400 binaural tones; 88% standards [1 kHz, 80 db, 80 ms], 11% frequency deviants [1.2 kHz], 11% duration deviants [40 ms]) and a neuropsychological test-battery. Patients were assessed with regard to clinical symptoms.ResultsCompared to healthy controls schizophrenia patients showed diminished MMN amplitude and shorter MMN latency to both deviants as well as an impaired neuropsychological test performance. Severity of positive symptoms was related to decreased MMN amplitude to duration deviants. Furthermore, enhanced verbal memory performance was associated with prolonged MMN latency to frequency deviants in patients.ConclusionThe present study corroborates previous results of a diminished MMN amplitude and its association with positive symptoms in schizophrenia patients. Both, the findings of a shorter latency to duration and frequency deviants and the relationship of the latter with verbal memory in patients, emphasize the relevance of the temporal aspect of early auditory discrimination processing in schizophrenia.

利培酮合并舒眠胶囊治疗精神分裂症的疗效及对患者糖、脂代谢的影响

Objective: To explore the curative effect and influence on glucose and lipid metabolism of risperidone with Shu Mian capsules in patients with schizophrenia . Methods: 128patients with chronic schizophrenia were randomly divided into the combined group (crisperidone combined with shu mian capsules group) and the single group (risperidone group ), each group was assessed the positive and negative syndrome scale (PANSS),the body mass index (BMI ) was measured and the blood glucose and blood lipid were detected before treatment and after 2,4,8 weekends respectively. After 4,8 weeks ,both the two groups were assessed by Wesconsin card sorting test ( WCST) curative effect and their cognitive function was evaluated . Results: The reacting time in the two groups were of no significantly difference , but compared with condition before treatment, cognitive function of the patients with schizophrenia was improved and their level of total cholesterol was significantly increased ( P < 0.05) in the combined group. BMI, blood glucose and blood lipid were significantly increased in single group after 8weeks’ treatment ( P < 0.05 or P < 0.01). Conclusion: Shu Mian capsules can lower negative symptoms and improve cognitive function of schizophrenia ,and the dverse reactions is mild. With therapeutic dose range, risperidone in combined group or single group can make equal reacting time, curative effect and affecting blood lipid metabolism in patients with schizophrenia. Single group shows more obvious influence on blood sugat and blood fat metabolismcan.

An investigation into the effects of tDCS dose on cognitive performance over time in patients with schizophrenia

Cognitive deficits in schizophrenia underlie more functional disability than any other symptom of the illness and existing treatments are largely inadequate. Non-invasive brain stimulation has been shown to enhance aspects of cognition in both healthy controls and patient populations; however there has been very little research into the use of tDCS for enhancing cognitive performance in schizophrenia. We conducted an initial investigation into the post stimulation effects of tDCS on cognitive performance in a repeated measures design in 18 patients with schizophrenia; in particular looking at dose of stimulation. Specifically, we provided a single 20-minute session of anodal left dorsolateral prefrontal tDCS (1mA, 2mA, sham) and measured performance on a working memory task across three time points post-stimulation (0, 20 and 40min). Our results revealed a significant improvement in performance over time following 2mA stimulation only. These findings speak to the feasibility of tDCS for enhancing cognitive performance in schizophrenia, as well as the importance of dose of stimulation.

Poster #S88 PROSPECTIVE MEMORY IMPAIRMENTS IN PATIENTS WITH FIRST-EPISODE SCHIZOPHRENIA: A 1-YEAR FOLLOW-UP STUDY

current/lifetime/amount of cigarettes, cannabis, alcohol and other drug use, duration and severity of illness, socioeconomic status, type and amount of antipsychotic medication. MetS+ had a significantly lower estimated IQ (sd) 94.9 (17.4) as compared to MetS100.1 (16.3) (t=2,54; p=0.012). Furthermore, MetS+ performed significantly worse on immediate (t=3,12; p=0.002) and delayed recall (t=2,92; p=0.004) as well as processing speed (t=−2,80; p=0.006) as compared to MetS. Linear regression analyses revealed that WAIS IQ scores (β=−0,156; p=0.026) and immediate memory (β=−0,098; p=0.003) were associated with waist circumference. Discussion: At a mean age of 30 years old, patients with schizophrenia and an additional diagnosis of MetS had lower IQ and performed worse on immediate and delayed recall and processing speed as compared to schizophrenia patients without MetS. This suggests that, even in the early stages of the disease, metabolic abnormalities are related to poor cognition in schizophrenia. Future studies are needed to examine whether treatment of MetS will also have a beneficial effect on cognitive performance in schizophrenia.

Neuritin, A Neurotrophic Factor in Nervous System Physiology

Neuritin (also known as candidate plasticity gene 15, cpg15) is an activity-induced glycosylphosphatidylinositol- anchored axonal protein and is mainly expressed in the brain. Neuritin mRNA expression is modulated by neurotrophic factors, synaptic activity, hormones, sensory experience, and electroconvulsive seizure therapy. Neuritin has several effects in the nervous system, such as promoting neurite outgrowth, modulating neurite outgrowth during neuronal differentiation, protecting motor neuron axons, promoting dendritic growth, shaping dendritic arbors of target neurons, regulating synaptic plasticity, stabilizing active synapses, promoting synaptic maturation and neuronal migration, promoting the development and maturation of visual cortical neurons, regulating apoptosis of proliferative neurons, and regenerating peripheral nerve and spinal axons. Neuritin is also implicated in cerebral ischemia, depression, and cognitive function in schizophrenia, and it upregulates transient outward K(+) currents in neurons, suggesting that neuritin may be a potential therapeutic target in peripheral and central nervous system diseases. This review focuses on the expression, distribution, and physiological functions of neuritin in the nervous system.

Peripheral interleukin-2 level is associated with negative symptoms and cognitive performance in schizophrenia

Although several studies have pointed to a possible role of interleukin 2 (IL-2) in schizophrenia (SZ), association between IL-2 and the different groups of symptoms has not been explored. The objective of this study was to investigate a possible correlation of peripheral IL-2 levels with symptoms and cognitive performance in patients with SZ. In addition, we compared the plasma levels of IL-2 between patients with SZ and healthy controls. Twenty-nine chronically medicated outpatients with SZ according to DSM-IV were compared with twenty-six healthy controls. The patients were evaluated with the Positive and Negative Syndrome Scale (PANSS), the Calgary Depression Scale for Schizophrenia (CDSS), the Clinical Global Impression (CGI) and the Global Assessment of Functioning (GAF). All the participants had blood collected into EDTA tubes by venipuncture between 9:00 and 10:00AM. Plasma concentrations of IL-2 were determined by cytometric bead array. A computerized neuropsychological battery assessed verbal learning, verbal fluency, working memory, set shifting, executive function, inhibition and intelligence. Patients with SZ had lower levels of IL-2 than healthy controls (p<0.001). In the SZ group, IL-2 levels were positively correlated with scores in the digit span test (rho=0.416, P=0.025) and intelligence (rho=0.464, P=0.011). We also found a negative correlation between IL-2 and total score in the negative subscale of PANSS (rho=−0.447, p=0.015). Our findings suggest that IL-2 may be involved in the mechanisms related to cognitive deterioration and negative symptomatology in schizophrenia.

EPA-1797 – Metabolic syndrome in young patients with schizophrenia is associated with poor cognitive performance

Background In schizophrenia about 40% of patients have an additional diagnosis of metabolic syndrome (MetS). In this present study the effect of MetS on cognition in a relatively young group of patients with schizophrenia was examined. Methods 290 schizophrenia patients (age/sd = 30/6.37 years old) were included in the study. Patients were divided into two groups, those with and those without MetS (MetS+/MetS-). Neuropsychological performance was assessed with the Wechsler Adult Intelligence Scale-III, the Continuous Performance Test-HQ, the Word Learning Task and the Response Shifting Task. Results 124 (42%) patients with schizophrenia met the criteria for MetS. MetS+ and MetS- groups did not differ on amount of cigarettes, alcohol, drug use, severity of illness, socioeconomic status and antipsychotic medication. MetS+ had a significantly lower estimated IQ (sd) 94.9 (17.4) compared to MetS- 100.1(16.3) (t=2,54; p=0.012). MetS+ performed significantly worse on immediate (t=3,12; p=0.002) and delayed recall (t=2,92; p=0.004) and processing speed (t=-2,80; p=0.006) as compared to MetS-. Linear regression analyses revealed that WAIS IQ scores (p=0.026) and immediate memory (p=0.003) were associated with waist circumference. Discussion Patients with schizophrenia and an additional diagnosis of MetS had lower IQ, performed worse on immediate and delayed recall and processing speed as compared to patients without MetS. This suggests that, even at a relatively young age, metabolic abnormalities are related to poor cognition in schizophrenia. Future studies are needed to examine whether treatment of MetS will also have a beneficial effect on cognitive performance in schizophrenia.

Routine clinical assessment of cognitive functioning in schizophrenia, major depressive disorder, and bipolar disorder

As more evidence points to the association of cognitive dysfunction with mental health disorders, the assessment of cognitive function in routine clinical care of these disorders is increasingly important. Despite this, it remains unknown how cognitive function is measured in routine clinical practice. The objective of this study was to assess psychiatrists' awareness of cognitive dysfunction in mental health disorders and their methods of cognitive assessment. An online survey was disseminated to psychiatrists in Europe, Asia, Australia and the United States. The survey asked about their perceptions of cognitive dysfunction in several mental health disorders, knowledge of cognitive assessment, method of cognitive assessment, and instruments used to measure cognitive function. Among the 61 respondents, most perceived that schizophrenia was associated with the greatest cognitive dysfunction. Many were unaware whether guidelines were available on cognitive assessment. In schizophrenia, 59% of psychiatrists reportedly used cognitive instruments, while the remainder relied solely on patient history interviews. The use of instruments to assess cognition in major depressive disorder (MDD) and bipolar disorder (BPD) was lower, 38% and 37% respectively. Of the reported instruments used, only a few were actually appropriate for use in the diseases of interest (12% in schizophrenia, 3% in MDD and 0% in BPD). Other instruments reported were clinical measures that did not assess cognition. These findings reveal some inconsistencies in psychiatrists' routine clinical evaluation of cognitive function. There appeared to be low use of true cognitive assessment instruments in clinical practice and confusion regarding what constituted a cognitive assessment instrument.

Could Infection Effect Cognitive Function in Schizophrenia ? : One Egyptian Center Study

ackground: Numerous viral infections, in utero or in childhood, have been associated with an increased risk of later developing schizophrenia. This may be explained by chronic infections or an altered immune status. Objectives: The present study aimed to measure levels of serum antibodies to some infectious agents in a sample of Egyptian patients with schizophrenia and to assess if there is correlation of cognitive functioning with this serum titer. Methods: the Arabic Version of Wechsler Adult Intelligence Scale Revised; selected subtests from Wechsler Memory Scale-Revised; Trail making test and Self-Assessment Scale of Cognitive Complaints in Schizophrenia were used to assess cognitive function in 102 newly diagnosed drug naive patients with schizophrenia and 124 healthy matched individuals. Solid phase enzyme immuno-assay (EIA) techniques were used to measure IgG class antibodies to Rubella virus, cytomegalovirus (CMV), Herpes simplex virus type 1&2 (HSV-1&2), and to Toxoplasma gondii (T. gondii) in the sera of the study individuals. Associations between serological exposure to selected infectious agents and cognitive function in schizophrenia were evaluated. Results: All studied infectious agents were more prevalent in patients with schizophrenia than in the control group. Higher anti-HSV1&2, and anti-Rubella IgG antibodies titers were significantly correlated with impaired cognitive tests, while anti-T. gondii IgG titer was insignificantly correlated with any of the neuro-cognitive tests. Conclusions: The higher prevalence of serum IgG antibodies to all analyzed infectious agents with higher titers within patients with schizophrenia emphasizes a possible role of infectious agents in the etiopatho-genesis of schizophrenia. The data indicates that not one specific agent might be responsible for schizophrenic symptoms. Impairment of the cognitive functions in patients with schizophrenia was associated with higher IgG titers to HSV1&2, and Rubella virus.

Dichotic listening, executive functions and grey matter cortical volume in patients with schizophrenia and healthy controls

Schizophrenia is characterized by cognitive impairment, especially in relation to executive functions. Brain structural abnormalities are also often seen in schizophrenia although little is known of the relationship between cognitive impairment and structural brain changes. Our aim was therefore to investigate this relationship further using MRI and a dichotic listening (DL) task with simple speech sounds and with instructions to focus attention and report only from the left or right ear stimulus. When instructed to focus attention on the left ear syllable a cognitive conflict is induced requiring the allocation of executive resources to be resolved. Grey matter (GM) volume was measured with MRI from four volumes of interests (VOIs), left and right frontal and temporal cortex, respectively, and correlated with DL performance. The results showed significant differences between the groups in their ability to focus attention on and report the left ear stimulus, which was accompanied by reduced GM volume in the left frontal and right temporal lobe VOIs. There was also a significant positive correlation between left frontal GM volume and performance on the DL task, for the groups combined. The results did not support a conclusion that an impairment in cognitive function in schizophrenia was driven by an corresponding impairment in brain structure, since there were no significant correlations when the groups were analyzed separately. It is however concluded that patients with schizophrenia are impaired in executive functions and that they also show reduced GM volumes in left frontal and right temporal lobe areas, compared to healthy controls.

Research progress in China on the assessment of cognitive function in schizophrenia.

SummaryCognitive impairment – one of the core symptoms of schizophrenia – has become a focus of research about schizophrenia in China and elsewhere. The main reason for the interest in cognitive functioning is that the degree of cognitive impairment is associated both with the current severity of the illness and with the prognosis of the illness due to its effect on individuals' ability to live independently and on their occupational and social functioning. The first study on cognitive function in schizophrenia in China was conducted in the late 1970s; more recently there has been a resurgence of interest in the area because of new information that has emerged as neuroimaging technologies have improved. The current review summarizes studies on cognitive impairment in schizophrenia conducted in China and proposes directions for future research in this area.

Schizophrenia Is a Cognitive Illness

Schizophrenia is currently classified as a psychotic disorder. This article posits that this emphasis on psychosis is a conceptual fallacy that has greatly contributed to the lack of progress in our understanding of this illness and hence has hampered the development of adequate treatments. Not only have cognitive and intellectual underperformance consistently been shown to be risk factors for schizophrenia, several studies have found that a decline in cognitive functioning precedes the onset of psychosis by almost a decade. Although the question of whether cognitive function continues to decline after psychosis onset is still debated, it is clear that cognitive function in schizophrenia is related to outcome and little influenced by antipsychotic treatment. Thus, our focus on defining (and preventing) the disorder on the basis of psychotic symptoms may be too narrow. Not only should cognition be recognized as the core component of the disorder, our diagnostic efforts should emphasize the changes in cognitive function that occur earlier in development. Putting the focus back on cognition may facilitate finding treatments for the illness before psychosis ever emerges.