Lisa J. Phillips

Neuroanatomical abnormalities before and after onset of psychosis: a cross-sectional and longitudinal MRI comparison

BACKGROUND Psychotic disorders, such as schizophrenia, are associated with neuroanatomical abnormalities, but whether these predate the onset of symptoms or develop progressively over the course of illness is unclear. We investigated this issue with MRI to study people with prodromal symptoms who are at ultra high-risk for the development of psychosis. METHODS We did two comparisons, cross-sectional and longitudinal. For the cross-sectional comparison, 75 people with prodromal signs of psychosis were scanned with MRI. After at least 12 months of follow-up, 23 (31%) had developed psychosis and 52 (69%) had not. Baseline MRI data from these two subgroups were compared. For the longitudinal comparison, 21 of the ultra high-risk individuals were scanned again with MRI after at least 12 months. Ten of these had developed psychosis and 11 had not. MRI data from baseline and follow-up were compared within each group of people. FINDINGS In the cross-sectional comparison, compared with people who did not develop psychosis, those who did develop the disorder had less grey matter in the right medial temporal, lateral temporal, and inferior frontal cortex, and in the cingulate cortex bilaterally. In the longitudinal comparison, when re-scanned, individuals who had developed psychosis showed a reduction in grey matter in the left parahippocampal, fusiform, orbitofrontal and cerebellar cortices, and the cingulate gyri. In those who had not become psychotic, longitudinal changes were restricted to the cerebellum. INTERPRETATION Some of the grey-matter abnormalities associated with psychotic disorders predate the onset of frank symptoms, whereas others appear in association with their first expression.

Mapping the onset of psychosis: the Comprehensive Assessment of At-Risk Mental States

Objective: Recognizing the prodrome of a first psychotic episode prospectively creates the opportunity of intervention, which could delay, ameliorate or even prevent onset. Valid criteria and a reliable methodology for identifying possible prodromes are needed. This paper describes an instrument, the Comprehensive Assessment of At-Risk Mental States (CAARMS), which has been designed for such a purpose. It has two functions: (i) to assess psychopathology thought to indicate imminent development of a first-episode psychotic disorder; and (ii) to determine if an individual meets criteria for being at ultra high risk (UHR) for onset of first psychotic disorder. This paper describes the pilot evaluation of the CAARMS.Method: Several methodologies were used to test the CAARMS. First, CAARMS scores in a group of UHR young people and the association between CAARMS scores and the risk of transition to psychotic disorder, were analysed. Second, CAARMS scores in a UHR group were compared to a control group. To asses...

Progressive Gray Matter Reduction of the Superior Temporal Gyrus During Transition to Psychosis

CONTEXT Longitudinal magnetic resonance imaging studies have shown progressive gray matter reduction in the superior temporal gyrus during the earliest phases of schizophrenia. It is unknown whether these progressive processes predate the onset of psychosis. OBJECTIVE To examine gray matter reduction of the superior temporal gyrus over time in individuals at risk for psychosis and in patients with first-episode psychosis. DESIGN Cross-sectional and longitudinal comparisons. SETTING Personal Assessment and Crisis Evaluation Clinic and Early Psychosis Preventions and Intervention Centre. PARTICIPANTS Thirty-five ultrahigh-risk individuals (of whom 12 later developed psychosis [UHRP] and 23 did not [UHRNP]), 23 patients with first-episode psychosis (FEP), and 22 control subjects recruited from the community. MAIN OUTCOME MEASURES Volumes of superior temporal subregions (planum polare, Heschl gyrus, planum temporale, and rostral and caudal regions) were measured at baseline and follow-up (mean, 1.8 years) and were compared across groups. RESULTS In cross-sectional comparisons, only the FEP group had significantly smaller planum temporale and caudal superior temporal gyrus than other groups at baseline, whereas male UHRP subjects also had a smaller planum temporale than controls at follow-up. In longitudinal comparison, UHRP and FEP patients showed significant gray matter reduction (approximately 2%-6% per year) in the planum polare, planum temporale, and caudal region compared with controls and/or UHRNP subjects. The FEP patients also exhibited progressive gray matter loss in the left Heschl gyrus (3.0% per year) and rostral region (3.8% per year), which were correlated with the severity of delusions at follow-up. CONCLUSIONS A progressive process in the superior temporal gyrus precedes the first expression of florid psychosis. These findings have important implications for underlying neurobiologic features of emerging psychotic disorders and emphasize the importance of early intervention during or before the first episode of psychosis.

Spatial working memory ability is a marker of risk-for-psychosis

BACKGROUND Working memory has been identified as a core cognitive deficit in schizophrenia that is associated with negative symptoms, but it is unclear whether it is impaired prior to onset of psychosis in symptomatic patients. METHOD Thirty-eight young people at ultra high-risk (UHR) of developing psychosis (of whom nine later became psychotic) were compared with 49 healthy controls on tests of spatial working memory (SWM) and delayed matching-to-sample (DMTS). RESULTS Both SWM and DMTS performance was significantly poorer in the UHR groups. Those who later became psychotic generally performed more poorly than those who did not, although this did not reach significance for any measure. A significant association between SWM errors and negative symptoms was seen in the later-psychotic group only (P = 0.02). CONCLUSIONS Spatial working memory abilities are impaired in those at high-risk for psychosis. The relationship between working memory and negative symptoms may be useful as a predictive tool.

Pituitary Volume Predicts Future Transition to Psychosis in Individuals at Ultra-High Risk of Developing Psychosis

BACKGROUND We examined pituitary volume before the onset of psychosis in subjects who were at ultra-high risk (UHR) for developing psychosis. METHODS Pituitary volume was measured on 1.5-mm, coronal, 1.5-T magnetic resonance images in 94 UHR subjects recruited from admissions to the Personal Assessment and Crisis Evaluation Clinic in Melbourne, Australia and in 49 healthy control subjects. The UHR subjects were scanned at baseline and were followed clinically for a minimum of 1 year to detect transition to psychosis. RESULTS Within the UHR group, a larger baseline pituitary volume was a significant predictor of future transition to psychosis. The UHR subjects who later went on to develop psychosis (UHR-P, n = 31) had a significantly larger (+12%; p = .001) baseline pituitary volume compared with UHR subjects who did not go on to develop psychosis (UHR-NP, n = 63). The survival analysis conducted by Cox regression showed that the risk of developing psychosis during the follow-up increased by 20% for every 10% increase in baseline pituitary volume (p = .002). Baseline pituitary volume of the UHR-NP subjects was smaller not only compared with UHR-P (as described above) but also compared with control subjects (-6%; p = .032). CONCLUSIONS The phase before the onset of psychosis is associated with a larger pituitary volume, suggesting activation of the HPA axis.

Neuroanatomical Abnormalities That Predate the Onset of Psychosis: A Multicenter Study

CONTEXT People experiencing possible prodromal symptoms of psychosis have a very high risk of developing the disorder, but it is not possible to predict, on the basis of their presenting clinical features, which individuals will subsequently become psychotic. Recent neuroimaging studies suggest that there are volumetric differences between individuals at ultra-high risk (UHR) for psychosis who later develop psychotic disorder and those who do not. However, the samples examined to date have been small, and the findings have been inconsistent. OBJECTIVE To assess brain structure in individuals at UHR for psychosis in a larger and more representative sample than in previous studies by combining magnetic resonance imaging data from 5 different scanning sites. DESIGN Case-control study. SETTING Multisite. PARTICIPANTS A total of 182 individuals at UHR and 167 healthy controls. Participants were observed clinically for a mean of 2 years. Forty-eight individuals (26.4%) in the UHR group developed psychosis and 134 did not. MAIN OUTCOME MEASURES Magnetic resonance images were acquired from each participant. Group differences in gray matter volume were examined using optimized voxel-based morphometry. RESULTS The UHR group as a whole had less gray matter volume than did controls in the frontal regions bilaterally. The UHR subgroup who later developed psychosis had less gray matter volume in the left parahippocampal cortex than did the UHR subgroup who did not. CONCLUSIONS Individuals at high risk for psychosis show alterations in regional gray matter volume regardless of whether they subsequently develop the disorder. In the UHR population, reduced left parahippocampal volume was specifically associated with the later onset of psychosis. Alterations in this region may, thus, be crucial to the expression of illness. Identifying abnormalities that specifically predate the onset of psychosis informs the development of clinical investigations designed to predict which individuals at high risk will subsequently develop the disorder.

Non-reduction in hippocampal volume is associated with higher risk of psychosis

Previous research using MRI scans has shown reduced hippocampal volumes in chronic schizophrenia and first-episode psychosis compared to well subjects. There are few MRI volumetric studies of high-risk cohorts and no studies that have compared structural measures between high-risk subjects who later developed a psychotic illness and those who did not. Therefore, the question of whether structural changes to the hippocampi precede the onset of an acute psychotic episode has not been answered. Hippocampal and whole brain volumes of 60 people at ultra high-risk (UHR) of developing a psychotic episode (identified through state and trait criteria) were obtained through MRI scan and compared with subjects with first episode psychosis (FEP: n=32), and no mental illness (n=139). Thirty-three percent (n=20) of the UHR cohort developed a psychotic disorder during the 12-month period following the MRI scan. The UHR group as a whole, like the FEP group, had significantly smaller left and right hippocampal volumes than the normal comparison group. Contrary to our initial hypothesis, the left hippocampal volume of the UHR subjects who developed a psychotic disorder was larger than the UHR-non-psychotic subgroup and the FEP group, but no differences were found between the UHR-psychotic and normal groups. The right hippocampus of the UHR-non-psychotic group was significantly smaller than the Normal group but not different to the FEP group. Furthermore, a larger left hippocampal volume of the UHR cohort at intake was associated with the subsequent development of acute psychosis rather than smaller volumes. These results contradicted the expected outcomes, which had been influenced by the neurodevelopmental model of the development of psychosis and an earlier study comparing hippocampal volumes of first episode, chronic schizophrenia and normal populations. One implication of these results is that a process of dynamic central nervous system change may occur during the onset phase of schizophrenia and related disorders, rather than earlier in life as suggested by the neurodevelopmental model. Alternatively, selection factors associated with the UHR cohort may have created a bias in the results. Replication of these results is required in other high-risk cohorts.

Ethics and early intervention in psychosis : keeping up the pace and staying in step

The intense clinical and research interest in early psychosis in recent years has highlighted a range of ethical issues which need to be considered carefully. Our perspective is based on 16 years of clinical and research experience with young people at this phase of illness as well as the research contributions of many others. We discuss the ethical dilemmas in relation to the three key foci, which make up the early psychosis paradigm. These are the pre-psychotic or prodromal phase, the period of untreated psychosis and the first psychotic episode and the critical period of recovery, which follows this. Most attention is devoted to the pre-psychotic period, however ethical considerations related to research in the other two clinical foci are briefly covered as well. Our contention is that the ethical issues are essentially identical to those arising in early intervention research in mainstream medicine. This has been concealed by inconsistency and emotion, which has great potential to confuse, politicize and derail rational debate. The legacy of the isolation of psychiatry from medicine and consequent prejudice and stigma in the professional as well as the public mind seems to be fueling a tendency in some societies to view psychiatric research as qualitatively different from other medical research. Sound clinical research data should be allowed to illuminate the options for potential consumers across all phases of illness. The alternative is research paralysis, which would force clinical practice to expand blindly without an evidence base.

Anatomic abnormalities of the anterior cingulate cortex before psychosis onset: an MRI study of ultra-high-risk individuals.

BACKGROUND Abnormalities of the anterior cingulate cortex (ACC) are frequently implicated in the pathophysiology of psychotic disorders, but whether such changes are apparent before psychosis onset remains unclear. In this study, we characterized prepsychotic ACC abnormalities in a sample of individuals at ultra-high-risk (UHR) for psychosis. METHODS Participants underwent baseline magnetic resonance imaging and were followed-up over 12-24 months to ascertain diagnostic outcomes. Baseline ACC morphometry was then compared between UHR individuals who developed psychosis (UHR-P; n = 35), those who did not (UHR-NP; n = 35), and healthy control subjects (n = 33). RESULTS Relative to control subjects, UHR-P individuals displayed bilateral thinning of a rostral paralimbic ACC region that was negatively correlated with negative symptoms, whereas UHR-NP individuals displayed a relative thickening of dorsal and rostral limbic areas that was correlated with anxiety ratings. Baseline ACC differences between the two UHR groups predicted time to psychosis onset, independently of symptomatology. Subdiagnostic comparisons revealed that changes in the UHR-P group were driven by individuals subsequently diagnosed with a schizophrenia spectrum psychosis. CONCLUSIONS These findings indicate that anatomic abnormalities of the ACC precede psychosis onset and that baseline ACC differences distinguish between UHR individuals who do and do not subsequently develop frank psychosis. They also indicate that prepsychotic changes are relatively specific to individuals who develop a schizophrenia spectrum disorder, suggesting they may represent a diagnostically specific risk marker.

Evidence of a dimensional relationship between schizotypy and schizophrenia: a systematic review.

The personality dimension of schizotypy is well established, and schizotypal traits can be taken to represent a proneness toward developing psychosis. Yet, there are competing theories about the latent structure of schizotypy. More specifically, there is controversy over the extent to which this propensity toward psychosis is present only in a small proportion of the population, or whether it is spread dimensionally throughout the general community. On the basis of accumulating research findings the present article argues for a fully dimensional model of schizotypy. It describes recent neurobiological, neuropsychological, social and environmental evidence supporting the idea that schizotypy in healthy populations, and disorders on the schizophrenia spectrum are fundamentally linked. Directions for further research are also considered.