Neuropsychological and clinical correlates of antisaccade task performance in schizophrenia

OBJECTIVES: To elucidate pathophysiologic mechanisms involved in abnormal antisaccade task performance in schizophrenia by investigating a possible relationship among antisaccade task performance, neuropsychological test results, and symptomatology in a group of young patients with recent-onset schizophrenia; to compare the effects of olanzapine and risperidone on antisaccades and reflexive saccades. BACKGROUND: Patients with schizophrenia consistently perform worse than controls on the antisaccade task in which the subject is required to inhibit a reflexive saccade to a suddenly appearing visual target and look in the opposite direction. METHODS: In 37 young (mean age 21 years), medicated patients with recent-onset schizophrenia the authors assessed antisaccades, reflexive saccades, neuropsychological test performance, and symptomatology. A subgroup of 18 patients was treated with olanzapine, and 15 patients were treated with risperidone. Reflexive-saccade and antisaccade task results were compared with those obtained in 13 control subjects. RESULTS: The antisaccade error rate was significantly higher in the patients than in the control subjects. In the patients, poor working memory function was related to increased antisaccade error rate. Severity of disorganization symptoms at intake was related to prolonged mean latency of the correct antisaccades. Patients on risperidone had a prolonged mean latency in the reflexive saccade task compared with patients using olanzapine. CONCLUSIONS: Abnormal antisaccade task performance is already present in early schizophrenia and may reflect working memory dysfunction. In future studies, medication effects should be considered in interpreting eye movement test results of patients with schizophrenia.     

Saccadic disinhibition in patients with acute and remitted schizophrenia and their first-degree biological relatives

OBJECTIVE: Performance on measures of saccadic inhibition and control was investigated in a large family study of schizophrenia to evaluate the utility of using antisaccade task performance as an endophenotypic marker of genetic liability for schizophrenia. METHOD: Ninety-five patients with acute schizophrenia and 116 of their first-degree biological relatives, 13 schizophrenia patients whose illness was in full remission, 35 patients with acute psychotic affective disorder, and 109 nonpsychiatric comparison subjects were administered antisaccade and prosaccade tasks. RESULTS: Both schizophrenia patient groups had a greater number of errors on the antisaccade task than did the first-degree relatives and the affective disorder group, which both had more errors than the comparison subjects. Among the first-degree relatives of the probands with acute schizophrenia, relatives of poor-performing patients performed worse on the antisaccade task than relatives of patients with good performance. Reflexive errors were not likely the result of interfering psychotic symptoms, medication, or medication side effects. Although the schizophrenia patients demonstrated other signs of saccadic abnormalities, these problems, which were not observed in their relatives even though they had high antisaccade error rates, seem unlikely to account for the higher antisaccade error rate of the schizophrenia patients. CONCLUSIONS: These findings suggest that saccadic disinhibition is strongly associated with the genetic liability for schizophrenia.     

The association between antisaccade task and working memory task performance in schizophrenia and bipolar disorder

To date, the research literature has yielded conflicting reports regarding the specificity of antisaccade deficits to schizophrenia. We sought to examine antisaccade and working memory task performance in schizophrenia patients and bipolar patients, as well as to examine the relationship between the two tasks in both patient populations. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 nonpatient controls were administered saccadic inhibition (antisaccade), working memory, and sensorimotor tasks. Compared with the controls, the schizophrenia patients displayed both antisaccade deficits and working memory deficits. In contrast, the bipolar patients produced significantly more errors on the antisaccade task than the controls, though the bipolar group performed similarly to the control group on the working memory task. Mediational analyses demonstrated that working memory partially mediates the relationship between patients' diagnostic group status and antisaccade task performance; working memory performance contributed uniquely to the prediction of antisaccade task performance in the two patient groups. Antisaccade deficits do not appear specific to schizophrenia. The results suggest that in schizophrenia, working memory and antisaccade tasks are tapping similar cognitive processes, whereas in bipolar patients the processes underlying antisaccade and working memory performance are disparate.     

Deficit of theory of mind in individuals at ultra-high-risk for schizophrenia

BACKGROUND: Although a deficit in social cognition is regarded as an early indicator of schizophrenia, few studies have investigated social cognition in ultra-high-risk (UHR) individuals. METHODS: Our investigation involved subjects at UHR for psychosis (N=33) and an age- and IQ-matched healthy control (HC) group (N=36). Two types of theory of mind (ToM) tasks and a neuropsychological test battery were measured. RESULTS: Compared to the HC group, the UHR group performed significantly worse for ToM tasks, with the effect size at an intermediate level (0.64-0.68). Furthermore, the UHR group showed impaired performance in the executive and working memory tests, but not verbal memory tests. These deficits for ToM tests observed in the UHR group were significantly correlated with set-shifting tasks. CONCLUSIONS: Deficits in social cognition may be modest at the prodromal stage of schizophrenia and may be attributed to prefrontal dysfunction. To prevent or delay transition to psychosis, there is a need for specific preventive strategies targeting social functioning for the UHR group.     

Reduced prepulse inhibition in adolescents at risk for psychosis: a 2-year follow-up study

Background

Reduced prepulse inhibition (PPI) of the auditory startle reflex is a hallmark feature of attention-processing deficits in patients with schizophrenia and other psychotic disorders. Recent evidence suggests that these deficits may also be present before the onset of psychosis in individuals at ultra-high risk (UHR) and become progressively worse as psychosis develops. We conducted a longitudinal follow-up study to observe the development of PPI over time in UHR adolescents and healthy controls.

Methods

Two-year follow-up data of PPI measures were compared between UHR adolescents and a matched control group of typically developing individuals.

Results

We included 42 UHR adolescents and 32 matched controls in our study. Compared with controls, UHR individuals showed reduced PPI at both assessments. Clinical improvement in UHR individuals was associated with an increase in PPI parameters.

Limitations

A developmental increase in startle magnitude partially confined the interpretation of the association between clinical status and PPI. Furthermore, post hoc analyses for UHR individuals who became psychotic between assessments had limited power owing to a low transition rate (14%).

Conclusion

Deficits in PPI are present before the onset of psychosis and represent a stable vulnerability marker over time in UHR individuals. The magnitude of this marker may partially depend on the severity of clinical symptoms.     

A case of rapid conversion to psychosis of delusional misidentification associated with derealisation,verbal memory impairment and FDG-PET imaging abnormalities

The delusional misidentification syndromes, occurring within the context of different nosological settings, such as schizophrenia, are psychopathological phenomena related to the experience of depersonalisation/derealisation. Extensive research indicates that individuals meeting specific “prodromal” criteria, such as attenuated psychotic symptoms, brief intermittent psychotic symptoms, or functional decline and family history of schizophrenia have increased risk for impending psychosis. Despite depersonalisation and/or derealisation often precede psychotic onset, they are not included among the prodromal criteria of the Australian–American approach. A 17-year-old boy with acute agitation, violent behaviour and aggression, and dissociative amnesia had a mild verbal memory impairment and temporo-limbic hypometabolism on the positron-emission tomography. The patient was assessed with both the ultra-high risk (UHR) and the basic symptom approaches and was not found to be prodromal with imminent risk of transition to psychosis. He was hospitalised briefly and 2 weeks after discharge he developed delusional misidentification. This case shows that even the integration of both UHR and basic symptoms criteria may give false negatives in the prediction of psychosis, especially in those cases in which a long prodromal phase is absent.     

Cognitive functioning in the schizophrenia prodrome

In the last decade, there has been an increasing interest in cognitive alterations during the early course of schizophrenia. From a clinical perspective, a better understanding of cognitive functioning in putative at-risk states for schizophrenia is essential for developing optimal early intervention models. Two approaches have more recently been combined to assess the entire course of the initial schizophrenia prodrome: the predictive "basic symptom at-risk" (BS) and the ultra high-risk (UHR) criteria. Basic symptoms are considered to be present during the entire disease progression, including the initial prodrome, while the onset of symptoms captured by the UHR criteria expresses further disease progression toward frank psychosis. The present study investigated the cognitive functioning in 93 subjects who met either BS or UHR criteria and thus were assumed to be at different points on the putative trajectory to psychosis. We compared them with 43 patients with a first episode of psychosis and to 49 help-seeking patient controls. All groups performed significantly below normative values. Both at-risk groups performed at intermediate levels between the first-episode (FE) group and normative values. The UHR group demonstrated intermediate performance between the FE and BS groups. Overall, auditory working memory, verbal fluency/processing speed, and declarative verbal memory were impaired the most. Our results suggest that cognitive impairments may still be modest in the early stages of the initial schizophrenia prodrome and thus support current efforts to intervene in the early course of impending schizophrenia because early intervention may prevent or delay the onset of frank psychosis and thus prevent further cognitive damage.     

Meta-analysis of Cognitive Deficits in Ultra-high Risk to Psychosis and First-Episode Psychosis: Do the Cognitive Deficits Progress Over,or After,the Onset of Psychosis?

Cognitive dysfunction is a well-established feature of schizophrenia, and there is evidence suggesting that cognitive deficits are secondary to abnormal neurodevelopment leading to problems in acquiring such abilities. However, it is not clear whether there is also a decline in cognitive performance over, or after, the onset of psychosis. Our objective was to quantitatively examine the longitudinal changes in cognitive function in patients who presented with first-episode psychosis (FEP), ultra-high risk (UHR) for psychosis, and controls. Electronic databases were searched for the studies published between January 1987 and February 2013. All studies reporting longitudinal cognitive data in FEP and UHR subjects were retrieved. We conducted meta-analyses of 25 studies including 905 patients with FEP, 560 patients at UHR, and 405 healthy controls. The cognitive performances of FEP, UHR, and healthy controls all significantly improved over time. There was no publication bias, and distributions of effect sizes were very homogenous. In FEP, the degree of improvement in verbal working memory and executive functions was significantly associated with reduction in negative symptoms. There was no evidence of cognitive decline in patients with UHR and FEP. In contrast, the cognitive performances of both groups improved at follow-up. These findings suggest that cognitive deficits are already established before the prodromal phases of psychosis. These data support the neurodevelopmental model rather than neurodegenerative and related staging models of schizophrenia.Key words: schizophrenia, psychosis, cognition, neuropsychology, longitudinal     

Elevated Antisaccade Error Rate as an Intermediate Phenotype for Psychosis Across Diagnostic Categories

Background: Elevated antisaccade error rate, reflecting problems with inhibitory behavioral control, is a promising intermediate phenotype for schizophrenia. Here, we consider whether it marks liability across psychotic disorders via common or different neurophysiological mechanisms and whether it represents a neurocognitive risk indicator apart from the generalized cognitive deficit. Methods: Schizophrenia (n = 267), schizoaffective (n = 150), and psychotic bipolar (n = 202) probands, their first-degree relatives (ns = 304, 193, 242, respectively), and healthy controls (n = 244), participating in the Bipolar-Schizophrenia Network on Intermediate Phenotypes consortium, performed antisaccade and prosaccade tasks and completed a neuropsychological battery. Results: Antisaccade error rate was elevated in proband groups with greatest deficit observed in schizophrenia and was unrelated to symptoms and antipsychotic treatment. Increased error rate was also observed among relatives, even those without history of psychosis or psychosis spectrum personality traits. Relatives’ deficits were similar across proband diagnoses. Error rate was familial and remained elevated in proband and relative groups after accounting for generalized cognitive impairment. Speed of attentional shifting, indexed by prosaccade latency, was similarly influenced in all groups by manipulations that freed vs increasingly engaged attention systems and was inversely associated with antisaccade error rate in all but schizophrenia probands. Conclusions: These findings indicate that elevated antisaccade error rate represents an intermediate phenotype for psychosis across diagnostic categories, and that it tracks risk beyond that attributable to the generalized cognitive deficit. The greater severity of antisaccade impairment in schizophrenia and its independence from attention shifting processes suggest more severe and specific prefrontal inhibitory control deficits in this disorder.Key words: schizophrenia, schizoaffective disorder, bipolar disorder, endophenotype, family study     

The relationship between IQ, memory, executive function, and processing speed in recent-onset psychosis: 1-year stability and clinical outcome

Studies commonly report poor performance in psychotic patients compared with controls on tasks testing a range of cognitive functions, but, because current IQ is often not matched between these groups, it is difficult to determine whether this represents a generalized deficit or specific abnormalities. Fifty-three first-episode psychosis patients and 53 healthy controls, one-to-one matched for sex, age, and full-scale current IQ, were compared on Wechsler Adult Intelligence Scale (WAIS) subtests representing indices of perceptual organization, verbal comprehension, processing speed, and working memory as well as other tests of executive function and episodic memory. The groups showed an equivalent pattern of performance on all WAIS subtests except digit symbol processing speed, on which the patients were significantly worse. Patients were also worse on measures where performance correlated with digit symbol score, namely working and verbal memory tasks. Standardized residual scores for each subtest were calculated for each patient using the difference between their actual subtest score and a predicted subtest score based on their full-scale IQ and the performance of controls. Scaled scores and residual scores were examined for relationships with clinical measures. Digit symbol-scaled score was significantly correlated with concurrent negative syndrome score at baseline, and digit symbol residual score significantly predicted residual negative symptoms at 1-year follow-up. In summary, our comparison of patients and controls precisely matched for IQ revealed that processing speed was attenuated in recent-onset schizophrenia, contributed significantly to working and episodic memory deficits, and was a prognostic factor for poor outcome at 1 year.     

Neuropsychology of subjects with ultra-high risk (UHR) of psychosis: A critical analysis of the literature

Cognitive disorders are currently considered as central components of disorders found in schizophrenia and are a major handicap for patients day to day. These disorders appear before the first psychotic episode, in the prodromal phase, during which time the symptoms are below the threshold for psychosis. People with these symptoms are considered as presenting an at-risk mental state (or at ultra-high risk, UHR of psychosis) and their risk for psychotic transition is between 20% and 40% within one year. Despite a number of studies, the chronology in which cognitive disorders appear in relation to the psychotic symptoms has not clearly been established and the study of the links between cognition and symptoms could improve our understanding of psychotic disorders. The detection of certain cognitive disorders before the onset of psychotic disorders could help improve early detection. We carried out a systematic analysis of the literature exploring cognitive disorders found in subjects with UHR for psychosis. The objective of most studies was to establish the predictive value for psychotic transition. Nevertheless study results have shown little consensus. Faced with this heterogeneity of results from past studies, we carried out a critical analysis of the literature and suggest areas of reflection for future research.     

Neurocognitive predictors of functional outcome two to 13 years after identification as ultra-high risk for psychosis

Background and aim

Little is known about the relationship between neurocognitive performance and functional outcome before the onset of frank psychosis. This longitudinal study aimed to investigate neurocognitive predictors of poor functional outcome in a group identified as ultra-high risk (UHR) for psychosis between two and 13 years prior.

Method

Individuals (N = 230) identified as UHR for psychosis at the PACE Clinic in Melbourne completed assessment of psychopathology, functioning and neurocognition at baseline and follow-up. The mean length of follow-up was 7.26 years (SD 3.05).

Results

Forty-one individuals with the poorest functional outcome were identified. Only 48.8% of this group had transitioned to psychosis. Poor functional outcome was associated with reduced performance at baseline in the specific neurocognitive domains of verbal learning and memory, processing speed and attention, and verbal fluency, but not global cognitive impairment. Reduced performance on a verbal story recall task, in combination with higher negative symptoms at baseline, was the best predictor of later poor outcome. Baseline positive psychotic symptoms and GAF scores were not associated with later poor outcome.

Discussion

To date, this is the longest follow-up study of an UHR sample. Poor functional outcome was associated with specific neurocognitive decrements, regardless of transition to psychosis. The detection of individuals with poor functioning at follow-up, against a background of previously identified risk factors for psychotic disorder, may yield a valid group in which to study biomarkers and treatment of schizophrenia.     

Proton magnetic resonance spectroscopy in first episode psychosis and ultra high-risk individuals

The underlying neurobiology of emerging psychotic disorders is not well understood. Recent neuroimaging findings have suggested that some brain areas are affected prior to the onset of psychosis, while changes occur in other brain regions during the transition to illness. Further, previous research using magnetic resonance spectroscopy (MRS) has generally demonstrated that there are changes to the brain chemistry of patients with schizophrenia. However, it is unclear whether these changes are present prior to or at the onset of the disorder, and to what extent they are specific to schizophrenia. In this study, we assessed the left medial temporal and left dorsolateral prefrontal regions of 56 patients in their first episode of a psychotic disorder, 30 young people at ultra high-risk (UHR) of developing psychosis, and 21 healthy controls, using proton MRS. Six of the UHR group developed a first episode psychosis over the study period. No differences were identified between the first episode and control groups for any metabolite ratio in either region of interest. This may reflect intact neuronal circuits in the early phase of psychotic disorders. There were also no differences between the UHR and control groups for the medial temporal region. However, there was a significant elevation of the NAA/Creatine and the Choline/Creatine ratios in the dorsolateral prefrontal region of the UHR group, which was interpreted as a decline in creatine indicative of hypometabolism. This finding did not discriminate between those UHR individuals who later became psychotic and those who did not.     

Neurocognitive performance in subjects at ultrahigh risk for schizophrenia: a comparison with first-episode schizophrenia

Objective

The aim of the present study was to explore the neurocognitive performance of patients at ultrahigh risk (UHR) compared with patients with first-episode (FE) schizophrenia and healthy control (HC) subjects.

Method

Twenty-seven subjects at UHR for schizophrenia, 25 patients in their FE of schizophrenia, and 33 HCs were included. All participants completed a neurocognitive battery, including tests of general intelligence, attention and working memory, executive function, and verbal and visual memory.

Results

Of the 3 groups, the FE subjects performed poorest at all neurocognitive tests, encompassing the broad range of impairments. The UHR subjects had a similar pattern of neuropsychological dysfunction but less severe than that of FE patients. The UHR subjects were particularly impaired on measures of attention and working memory, executive function, and verbal memory compared with the HCs.

Conclusion

These findings are consistent with the view that the neurocognitive impairments of schizophrenia are neurodevelopmental in nature and, although less severe, those impairments are mostly in place before the onset of the first frank psychotic episode. Neurocognitive impairments may play an important role in the pathogenesis of early psychosis and could help to clarify individuals at UHR for schizophrenia.     

Do antisaccade deficits in schizophrenia provide evidence of a specific inhibitory function?

BACKGROUND: Despite its inhibitory control requirements, antisaccade deficits have been consistently associated with working memory impairments in schizophrenia. We investigated whether variance in antisaccade performance could be better accounted for in terms of a specific inhibitory function. METHOD: We assessed 48 clinically stable out-patients with schizophrenia on an antisaccade task, as well as on measures of spatial and verbal working memory, sustained selective attention, and a simple motoric go/no-go measure of response inhibition. RESULTS: In a stepwise multiple regression analysis, go/no-go task performance accounted for a considerably greater percentage of variance in antisaccade performance (25.3%) than either working memory (8.4%) or sustained selective attention task (9.1%). DISCUSSION: We conclude that antisaccade deficits in schizophrenia appear to be better understood in terms of a specific deficit of inhibitory control than in terms of more general difficulties with context maintenance or goal neglect.     

White matter abnormalities in subjects at ultra high-risk for schizophrenia and first-episode schizophrenic patients

Schizophrenia is associated with neuroanatomical abnormalities. Gray matter decrease seems to predate first schizophrenic episode. Whether white matter abnormalities predate the onset of psychotic symptoms is unclear. We investigated this issue using voxel-based morphometry (VBM) of structural magnetic resonance images to examine individuals with prodromal symptoms who were at ultra high-risk (UHR) of developing schizophrenia and compared them to first-episode schizophrenic patients and healthy controls. White matter volume maps from high-resolution magnetic resonance T1 weighted whole brain images were analyzed in a cross-sectional study using SPM2 in 30 UHR patients, 23 first-episode schizophrenic patients and 29 healthy controls. UHR patients showed significant lower white matter volume in the right superior temporal lobe compared to healthy controls. First-episode patients with schizophrenia showed widespread smaller white matter volume bilaterally compared to UHR patients. This study provides first evidence for smaller white matter volume in the right temporal lobe of UHR patients, one of the key structures in the pathophysiology of schizophrenia. Furthermore, white matter abnormalities seem to progress after transition into schizophrenia.     

Effects of psychotic state and task demand on prefrontal function in schizophrenia: an fMRI study of overt verbal fluency

OBJECTIVE: Impaired prefrontal cortical function is regarded as a central feature of schizophrenia. Although many neuroimaging studies have found evidence of abnormal prefrontal activation when patients with schizophrenia perform cognitive tasks, the extent to which this abnormality depends on the presence of active psychotic symptoms and on the demands of the task is unclear. The authors tested the hypothesis that prefrontal functional abnormalities in schizophrenia would be more evident in patients with active psychosis than in patients who were in remission and would become more apparent in the face of increasing task demands. METHOD: The authors used functional magnetic resonance imaging (fMRI) to examine prefrontal cortical activity during a paced letter verbal fluency task in three groups of subjects: acutely psychotic patients with schizophrenia, schizophrenia patients in remission, and healthy volunteers. Online subject performance was measured by utilizing a clustered fMRI acquisition sequence that allowed overt verbal responses to be made in the relative absence of scanner noise. RESULTS: Patients with schizophrenia showed less activation than the healthy comparison subjects in the anterior cingulate and the inferior frontal and right middle frontal cortices, independent of psychotic state and task demand. Acutely psychotic patients showed less activation than the healthy comparison subjects, but these differences were less marked than the differences between the patients in remission and the healthy comparison subjects. Acutely psychotic patients had less activation than the comparison subjects in the anterior cingulate but no significant difference in lateral prefrontal activation. Increasing task demand led to greater anterior cingulate and middle frontal activation in patients with active psychosis than in patients in remission. CONCLUSIONS: Schizophrenia is associated with impaired prefrontal function, but its manifestation depends on the severity of psychotic symptoms and the level of task difficulty.     

Visual object working memory function and clinical symptoms in schizophrenia

OBJECTIVE: The presence of working memory deficits suggests abnormalities of prefrontal cortex (PFC) in schizophrenia. Although much is known about spatial working memory deficits in schizophrenia, including its potential as a phenotypic marker, it is unclear whether object working memory is similarly affected. Our goal was to examine nonspatial, object working memory function in relation to clinical symptoms. METHODS: We assessed object working memory and clinical symptoms in 28 schizophrenia patients during acute psychotic episode and 4 months later during partial remission. Delayed-matching-to-sample tasks for familiar object (DMTS-F) and novel shapes (DMTS-N) were used. Symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). 33 age-matched normal subjects were also tested over the same time period. RESULTS: Acutely psychotic patients showed deficits in both DMTS-F and DMTS-N. Four months later, their DMTS-F performance improved significantly but deficits in DMTS-N were still present. During acute psychosis, symptoms correlated with DMTS-F but not with the DMTS-N. Four months later, negative symptoms correlated with both tasks. CONCLUSIONS: Object working memory as measured by DMTS-N was impaired in schizophrenia patients during both acute and chronic states. When schizophrenia patients were in partial remission, object working memory was associated with negative symptoms.     

Stress and protective factors in individuals at ultra-high risk for psychosis, first episode psychosis and healthy controls

Stress-vulnerability models of schizophrenia regard psychosocial stress as an important factor in the onset and aggravation of psychotic symptoms, but such research in the early phases of psychosis is limited. Protective factors against the effects of stress might be the key to understanding some inconclusive findings and to the development of optimal psychosocial interventions. The present study compared self-reported levels of stress, self-esteem, social support and active coping in 32 patients with a first episode of psychosis (FEP), 30 individuals at ultra-high risk for psychosis (UHR) and 30 healthy controls. Associations with symptoms of psychosis were assessed in both patient groups. Individuals at UHR reported significantly higher stress levels compared to FEP patients. Both patient groups showed lower self-esteem compared to controls, and the UHR group reported lower social support and active coping than controls. These group differences could not be explained by age and dose of antipsychotic medication in the FEP group. In the UHR group, higher stress levels and lower self-esteem were associated with more severe positive and depressive symptoms on the Brief Psychiatric Rating Scale. Multiple regression analyses revealed that stress was the only significant predictor for both symptom measures and that the relationship was not moderated by self-esteem. Our findings show that individuals at UHR for psychosis experience high levels of psychosocial stress and marked deficits in protective factors. The results suggest that psychosocial interventions targeted at reducing stress levels and improving resilience in this population may be beneficial in improving outcomes.     

Transition to Psychosis Associated With Prefrontal and Subcortical Dysfunction in Ultra High-Risk Individuals

Background: People at ultra high risk (UHR) of psychosis have an elevated risk of developing a psychotic disorder, but it is difficult to predict which individuals will make a transition to frank illness. We investigated whether functional magnetic resonance imaging (fMRI) in conjunction with a phonological fluency task at presentation could distinguish subjects who subsequently developed psychosis from those who did not. Methods: Sixty-five subjects (41 with an UHR and 24 healthy controls) were assessed at clinical presentation using fMRI, in conjunction with a verbal fluency task. [18F]-DOPA positron emission tomography (PET) data were also available in a subgroup of 21 UHR and 14 healthy controls subjects. UHR subjects were followed clinically for at least 2 years. Results: Compared with UHR subjects who did not become psychotic, UHR subjects who subsequently developed psychosis showed increased activation in bilateral prefrontal cortex (PFC), brainstem (midbrain/basilar pons), the left hippocampus, and greater midbrain-PFC connectivity. Furthermore, exploratory analysis of [18F]-DOPA PET data showed that transition to psychosis was associated with elevated dopaminergic function in the brainstem region. Conclusions: In people at high risk of psychosis, increased activation in a network of cortical and subcortical regions may predict the subsequent onset of illness. Functional neuroimaging, in conjunction with clinical assessment and other investigations, may facilitate the prediction of outcome in subjects who are vulnerable to psychosis.