[show abstract][hide abstract] ABSTRACT: BACKGROUND: Grey matter volume and cortical thickness represent two complementary aspects of brain structure. Several studies have described reductions in grey matter volume in people at ultra-high risk (UHR) of psychosis; however, little is known about cortical thickness in this group. The aim of the present study was to investigate cortical thickness alterations in UHR subjects and compare individuals who subsequently did and did not develop psychosis. Method We examined magnetic resonance imaging data collected at four different scanning sites. The UHR subjects were followed up for at least 2 years. Subsequent to scanning, 50 UHR subjects developed psychosis and 117 did not. Cortical thickness was examined in regions previously identified as sites of neuroanatomical alterations in UHR subjects, using voxel-based cortical thickness. RESULTS: At baseline UHR subjects, compared with controls, showed reduced cortical thickness in the right parahippocampal gyrus (p < 0.05, familywise error corrected). There were no significant differences in cortical thickness between the UHR subjects who later developed psychosis and those who did not. CONCLUSIONS: These data suggest that UHR symptomatology is characterized by alterations in the thickness of the medial temporal cortex. We did not find evidence that the later progression to psychosis was linked to additional alterations in cortical thickness, although we cannot exclude the possibility that the study lacked sufficient power to detect such differences.
Psychological Medicine 05/2013; · 5.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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 towards 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.
[show abstract][hide abstract] ABSTRACT: PURPOSE: Vocational recovery is a primary treatment goal of young people with first-episode psychosis (FEP), yet treatment in this domain is often delayed due to concerns that it might be too stressful. This study aimed to examine whether a relationship exists between vocational status and level of perceived stress and daily hassles in FEP. METHODS: Forty-seven FEP participants were recruited upon admission to the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne. Demographics, psychopathology, perceived stress (Perceived Stress Scale; PSS) and daily hassles (Hassles Scale; HS) were measured. RESULTS: Regarding vocational status, 19 participants were unemployed, 13 were employed, 14 were students, and 1 reported 'home duties'. ANOVAs and post hoc tests comparing the first three groups on perceived stress and daily hassles revealed that the mean PSS Total and mean PSS Distress scores of the employed group were significantly lower than those of the unemployed and student groups. Regarding hassles scores, the employed group had a significantly lower mean Hassles Intensity score than the unemployed group. Results were largely unchanged when covariates were included. There were no significant differences between the three groups in levels of anxiety, negative or positive symptoms. The employed group reported lower depression than the student group, but this finding disappeared after controlling for gender. CONCLUSIONS: These results provide preliminary evidence supporting the notion that working or studying is not associated with increased perceived stress or daily hassles in FEP. The findings require replication in larger samples and in different phases of psychosis.
[show abstract][hide abstract] ABSTRACT: Objective:Impaired regulation of the hypothalamic-pituitary-adrenal (HPA) axis and hyper-activity of this system have been described in patients with psychosis. Conversely, some psychiatric disorders such as post-traumatic stress disorder (PTSD) are characterised by HPA hypo-activity, which could be related to prior exposure to trauma. This study examined the cortisol response to the administration of low-dose dexamethasone in first-episode psychosis (FEP) patients and its relationship to childhood trauma.Method:The low-dose (0.25 mg) Dexamethasone Suppression Test (DST) was performed in 21 neuroleptic-naïve or minimally treated FEP patients and 20 healthy control participants. Childhood traumatic events were assessed in all participants using the Childhood Trauma Questionnaire (CTQ) and psychiatric symptoms were assessed in patients using standard rating scales.Results:FEP patients reported significantly higher rates of childhood trauma compared to controls (p = 0.001) and exhibited lower basal (a.m.) cortisol (p = 0.04) and an increased rate of cortisol hyper-suppression following dexamethasone administration compared to controls (33% (7/21) vs 5% (1/20), respectively; p = 0.04). There were no significant group differences in mean cortisol decline or percent cortisol suppression following the 0.25 mg DST. This study shows for the first time that a subset of patients experiencing their first episode of psychosis display enhanced cortisol suppression.Conclusions:These findings suggest there may be distinct profiles of HPA axis dysfunction in psychosis which should be further explored.
Australian and New Zealand Journal of Psychiatry 11/2012; · 3.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has been suggested that some cases of schizophrenia may be caused by an interaction between physiological risk factors and exposure to certain neurotropic infectious agents such as Herpes Simplex Virus type 1 (HSV1). This study investigated whether HSV1 exposure was associated with structural brain abnormalities in individuals who, because of genetic or other factors, were deemed at ultra high risk (UHR) of developing psychosis. Twenty-five UHR individuals with a history of HSV1 exposure (HSV1+), 33 UHR participants without a history of HSV1 exposure (HSV1-) and 19 healthy controls participated in the study. All participants underwent a T1-weighted structural MRI scan, and HSV1 exposure was determined based on the presence of IgG class antibodies in the blood serum. Voxel based morphometry revealed that the HSV1+ participants exhibited volumetric gray matter reductions in the cuneus, relative to both the HSV1--and healthy control participants (p<0.05, small volume corrected for familywise error). The results of the study suggest that a history of HSV1 infection is associated with volumetric gray matter reductions in individuals at ultra-high risk for developing psychosis, and are consistent with previous studies that have identified structural gray matter abnormalities in HSV1-infected patients with established schizophrenia.
Schizophrenia Research 03/2012; 135(1-3):175-80. · 4.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate if low-dose lithium may counteract the microstructural and metabolic brain changes proposed to occur in individuals at ultra-high risk (UHR) for psychosis.
Hippocampal T2 relaxation time (HT2RT) and proton magnetic resonance spectroscopy ((1)H-MRS) measurements were performed prior to initiation and following three months of treatment in 11 UHR patients receiving low-dose lithium and 10 UHR patients receiving treatment as usual (TAU). HT2RT and (1)H-MRS percentage change scores between scans were compared using repeated measures ANOVA and correlated with behavioural change scores.
Low-dose lithium significantly reduced HT2RT compared to TAU (p=0.018). No significant group by time effects was seen for any brain metabolites as measured with (1)H-MRS, although myo-inositol, creatine, choline-containing compounds and NAA increased in the group receiving low-dose lithium and decreased or remained unchanged in subjects receiving TAU.
This pilot study suggests that low-dose lithium may protect the microstructure of the hippocampus in UHR states as reflected by significantly decreasing HT2RT. Larger scale replication studies in UHR states using T2 relaxation time as a proxy for emerging brain pathology seem a feasible mean to test neuroprotective strategies such as low-dose lithium as potential treatments to delay or even prevent the progression to full-blown disorder.
Current pharmaceutical design 01/2012; 18(4):570-5. · 4.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although the experience of stress and associated coping responses are thought to play a role in the onset of schizophrenia and other psychotic disorders, there is little empirical evidence to support such a relationship. The relatively recent development of validated and reliable criteria for identifying young people at "ultra" high-risk (UHR) of psychosis has enabled the process of illness onset to be studied more closely than was previously possible.
This longitudinal study compared the experiences of stress and coping between a UHR cohort (N=143) and a healthy comparison group (HC group, N=32).
The UHR group experienced significantly fewer life events over a 12-month period than the HC group, but there was no difference in the experience of minor events or "hassles". However, the UHR group reported feeling significantly more distressed by events, felt they coped more poorly and utilized different coping strategies.
The appraisals made about stressors differentiated the groups and was associated with differences in coping and distress levels. This suggests that treatment strategies focusing on stress management and enhancing coping skills might be important components of preventive interventions.
Behavioural and Cognitive Psychotherapy 07/2011; 40(1):69-88. · 1.69 Impact Factor
[show abstract][hide abstract] ABSTRACT: The treatment of psychotic disorders such as schizophrenia, schizophreniform, and bipolar disorder had been viewed with pessimism
until a shift in focus from established or chronic illness to earlier phases of illness around the onset highlighted opportunities
for enhanced recovery. The early psychosis focus emerged from recognition that the underlying nature of the illnesses would
be better studied in this phase of disorder (1). A welcome by-product has been the revival of interest in a realistic preventive treatment approach centering primarily
on enhanced detection and treatment of first episode psychosis (2,3,4, 5). It has also been recognized that even prior to the onset of frank psychosis, during the prodromal phase, the changes underpinning
the illness are already active although less obtrusively, and lead to substantial and progressive distress and disability
(6). The major emphasis to date has been on limiting the psychosocial, and possibly biological (7), damage which flows from delays in treatment which occur even after the onset of frank psychotic symptoms (2, 8). However, to a significant extent, the horse may well have bolted by this stage. The bulk of the early phase psychosocial
disability has generally emerged by the advent of the prepsychotic phase, and could therefore set a ceiling for recovery even
when timely treatment of the first psychotic episode is ultimately available (6, 9,10). This suggests that the prepsychotic phase is the “critical period” (11) par excellence for intervention efforts.
[show abstract][hide abstract] ABSTRACT: 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.
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.
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.
Magnetic resonance images were acquired from each participant. Group differences in gray matter volume were examined using optimized voxel-based morphometry.
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.
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.
Archives of general psychiatry 05/2011; 68(5):489-95. · 12.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: Recent neuroimaging investigations have identified a relationship between psychotic symptoms in schizophrenia and abnormal brain connectivity. On the basis of the continuum model of psychosis, it was hypothesized that schizotypal traits in healthy control participants would be associated with relatively impaired frontotemporal white matter health as assessed using diffusion tensor imaging. Twenty-one participants (12 women and 9 men aged 18 to 58 years) completed the Schizotypal Personality Questionnaire (SPQ) and underwent diffusion-weighted magnetic resonance imaging scanning as part of a larger study. White matter integrity for the major association fibre tracts was assessed using standard measures of diffusivity, specifically fractional anisotropy (FA) and axial and radial diffusivity. A series of negative binomial regressions yielded significant relationships between reduced FA in seven white matter tracts and increased scores on the SPQ cognitive-perceptual factor. These findings are consistent with research relating brain connectivity to the positive symptoms of schizophrenia, suggesting that the neurobiological bases of schizotypal personality in healthy controls may be analogous to the neurobiological bases of schizophrenia spectrum disorders.
The Journal of nervous and mental disease 05/2011; 199(5):348-53. · 1.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: It remains unclear whether brain structural abnormalities observed before the onset of psychosis are specific to schizophrenia or are common to all psychotic disorders. This study aimed to measure regional gray matter volume prior to the onset of schizophreniform and of affective psychoses. We investigated 102 subjects at ultrahigh risk (UHR) of developing psychosis recruited from the Personal Assessment and Crisis Evaluation Clinic in Melbourne, Australia. Twenty-eight of these subjects developed psychosis subsequent to scanning: 19 schizophrenia, 7 affective psychoses, and 2 other psychoses. We examined regional gray matter volume using 1.5 mm thick, coronal, 1.5 Tesla magnetic resonance imaging and voxel-based morphometry methods of image analysis. Subjects were scanned at presentation and were followed up clinically for a minimum of 12 months, to detect later transition to psychosis. We found that both groups of subjects who subsequently developed psychosis (schizophrenia and affective psychosis) showed reductions in the frontal cortex relative to UHR subjects who did not develop psychosis. The subgroup that subsequently developed schizophrenia also showed smaller volumes in the parietal cortex and, at trend level, in the temporal cortex, whereas those who developed an affective psychosis had significantly smaller subgenual cingulate volumes. These preliminary findings suggest that volumetric abnormalities in UHR individuals developing schizophrenia vs affective psychoses comprise a combination of features that predate both disorders and others that may be specific to the nature of the subsequent disorder.
[show abstract][hide abstract] ABSTRACT: Dehydroepiandrosterone (DHEA) and its sulphate form (DHEA) are neuroactive steroids with antiglucocorticoid properties. An imbalance in the ratio of cortisol to DHEA(S) has been implicated in the pathophysiology of stress-related psychiatric disorders. This study prospectively investigated circulating cortisol, DHEAS and their ratio in first-episode psychosis (FEP) patients compared to healthy controls, and their relationship to perceived stress, psychotic, negative and mood symptoms.
Blood cortisol and DHEAS levels were obtained in 39 neuroleptic-naïve or minimally-treated FEP patients and 25 controls. Twenty-three patients and 15 controls received repeat assessments after 12 weeks. Perceived stress was assessed using the Perceived Stress Scale and symptoms were assessed in patients using standard rating scales.
At baseline, no differences were observed in cortisol, DHEAS or the cortisol/DHEAS ratio between patients and controls. There were also no group differences in the change in these biological variables during the study period. Within FEP patients, decreases in cortisol and the cortisol/DHEAS ratio over time were directly related to the improvement in depression (r = 0.45; p = 0.031, r = 0.52; p = 0.01), negative (r = 0.51; p = 0.006, r = 0.55; p = 0.008) and psychotic symptoms (cortisol only, r = 0.53; p = 0.01). Perceived stress significantly correlated with DHEAS (r = 0.51; p = 0.019) and the cortisol/DHEAS ratio (r = -0.49; p = 0.024) in controls, but not patients, possibly reflecting an impaired hormonal response to stress in FEP patients.
These findings further support the involvement of the stress system in the pathophysiology of psychotic disorders, with implications for treatment strategies that modulate these neurosteroids.
Journal of psychiatric research 02/2011; 45(2):249-55. · 3.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cognitive therapy and/or low-dose antipsychotic administered during the prodromal phase of schizophrenia may prevent or delay the onset of full-blown illness. However, it is unclear which of these treatments are most effective, how long treatment should be given, and whether effects will be sustained over a prolonged period.
In order to examine these issues, we conducted a randomized controlled trial of cognitive therapy + risperidone; cognitive therapy + placebo; and supportive therapy + placebo in young people at ultra high risk for developing a psychotic disorder (that is, putatively prodromal). The main outcome was transition to psychotic disorder, with level of symptoms and functioning the secondary outcomes. This article reports the interim 6-month follow-up results. The study was conducted from August 2000 to May 2007.
Of a possible 464 eligible ultra high risk individuals, 115 were recruited to the randomized controlled trial (cognitive therapy + risperidone, n = 43; cognitive therapy + placebo, n = 44; and supportive therapy + placebo, n = 28). An additional 78 individuals agreed to follow-up assessments but not to randomization ("monitoring group," n = 78). At 6 months, 8 of the 115 participants (7.0%) and 4 of the monitoring group (5.1%) had developed psychotic disorder. There were no significant differences between the 3 randomized groups (log rank test, P = .92) or between all 4 groups (log rank test, P = .93). There was also no difference between the 4 groups in secondary measures, with all groups showing a reduction in symptoms and increased functioning.
Rates of transition to psychosis were lower than expected, particularly in the control supportive therapy + placebo group. This may have accounted for the negative finding, as the sample was therefore underpowered to find any difference between groups. Alternatively, it may be that all treatments were equally effective or equally ineffective at 6 months.
http://www.anzctr.org.au Identifier: ACTRN012605000247673.
The Journal of Clinical Psychiatry 10/2010; 72(4):430-40. · 5.81 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although the hippocampus is a key brain region in the pathophysiology of schizophrenia, it is unclear whether structural or biochemical abnormalities predate illness onset. In this study, we used magnetic resonance imaging and spectroscopy data acquired prior to both the onset of psychosis and treatment with antipsychotics to determine this. Sixty-six young people clinically at ultra high-risk of development of psychosis were recruited, 59 of whom did not later develop a psychotic disorder and 7 who had done so after at least 24 months follow-up. These participants were compared with 29 healthy comparison subjects on multiple independent magnetic resonance measures: hippocampal volume, hippocampal T2 relaxation time, and medial temporal lobe metabolite concentrations (including N-acetylaspartate). We found similar reductions in left hippocampal volume in the at-risk group compared to comparison subjects regardless of later transition status; on the right this only reached significance for the at-risk group who did not transition to psychosis. T2 relaxation time in the left hippocampal head was significantly elevated in the later-psychotic group, and this elevation positively correlated with total positive symptoms in the UHR group as a whole. Medial temporal lobe metabolite concentrations did not differ. These findings suggest that there are subtle pathological changes in the hippocampus prior to the development of psychosis, but that they are limited to the left hippocampal head. However, standard measures of neuroanatomical disturbance do not appear to be predictive of later transition, and instead are likely to be non-specific and common in cases that later develop a non-psychotic disorder.
[show abstract][hide abstract] ABSTRACT: The aim of the present study was to investigate whether volumetric abnormalities of the caudate nuclei predate the onset of psychotic illness. Caudate nuclei volume (CNVs), excluding the tail, were measured using region-of-interest (ROI) tracing of magnetic resonance imaging (MRI) scans acquired on a 1.5T scanner. Subjects included 39 individuals deemed at ultra-high risk of psychosis who converted to psychosis (UHR-P) after initial MRI scanning; 39 matched individuals at ultra-high risk who did not convert to psychosis (UHR-NP); and 39 matched healthy controls. All subjects were neuroleptic-naïve. After adjusting CNVs for intracranial volume (ICV), univariate analyses of variance and repeated measures analyses of variance were undertaken to examine the relationship of CNVs to psychosis transition and to family history of psychosis. Pearson's correlations were used to investigate the relationship of psychopathological scores to CNVs. CNVs did not differ significantly between UHR individuals and healthy controls, and there was no significant difference between converters and non-converters to psychosis. In the UHR group, presence of family history of psychosis was not related to CNVs. There was no correlation between CNVs and either positive or negative symptoms of schizophrenia. Significant associations were found between larger CNV and increased errors on a spatial working memory task but better verbal fluency performance. These data suggest that the caudate is macroscopically normal prior to illness onset, while the relationship to tasks of executive function may implicate the caudate together with its connections to prefrontal regions. Future research should examine changes longitudinally together with analysis of shape to assess subregions of the caudate that connect with prefrontal cortex.
Psychiatry Research 06/2010; 182(3):223-30. · 2.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study was designed to identify early symptoms associated with the occurrence of psychosis during adolescence.
Participants were recruited in the Republic of Palau, an isolated island nation in Micronesia with a prevalence rate for schizophrenia of 1.99%. Diagnostic interviews were used to obtain reports of early and current symptoms from 112 genetically high-risk (GHR) and 208 genetically low-risk (GLR) adolescents (ages 16-23). Based on current psychotic symptoms, participants were sorted into three groups: non-clinical, at-risk/symptomatic risk and clinically symptomatic.
Multivariate analysis of variance revealed several between-group differences on rates of early symptoms. Most notably, youth who were in the GHR-clinically symptomatic group reported significantly higher rates of early marijuana use than GLR-clinically symptomatic youth, who were significantly more likely to report early symptoms of depression and behaviour disorders. In addition, several gender based differences in the link between early symptoms and adolescent onset psychosis were noted.
Findings are generally consistent with previous research on early indicators, though several unexpected findings suggest that results from this study may not be fully generalizable beyond this relatively isolated and culturally distinct Micronesian nation.
Early Intervention in Psychiatry 05/2010; 4(2):153-61. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Morphological abnormalities of the superior temporal gyrus have been consistently reported in schizophrenia, but the timing of their occurrence remains unclear.
To determine whether individuals exhibit superior temporal gyral changes before the onset of psychosis.
We used magnetic resonance imaging to examine grey matter volumes of the superior temporal gyrus and its subregions (planum polare, Heschl's gyrus, planum temporale, and rostral and caudal regions) in 97 antipsychotic-naive individuals at ultra-high risk of psychosis, of whom 31 subsequently developed psychosis and 66 did not, and 42 controls.
Those at risk of psychosis had significantly smaller superior temporal gyri at baseline compared with controls bilaterally, without any prominent subregional effect; however, there was no difference between those who did and did not subsequently develop psychosis.
Our findings indicate that grey matter reductions of the superior temporal gyrus are present before psychosis onset, and are not due to medication, but these baseline changes are not predictive of transition to psychosis.
The British journal of psychiatry: the journal of mental science 03/2010; 196(3):206-11. · 6.62 Impact Factor
[show abstract][hide abstract] ABSTRACT: This paper focuses on the role of adoption and family relations as moderators of genetic risk for psychotic disorders.
Participants included 184 adolescents in the Republic of Palau identified to be at genetic risk for schizophrenia and other psychotic disorders. Palau is an island nation in Micronesia with a lifetime prevalence of 1.99% for schizophrenia and 2.67% for psychotic disorders more broadly defined. In Palauan culture, kinship adoption is a common cultural practice; 47 of the 184 participants had been adopted at an early age. The current study was designed to test the hypothesis that adoption would function as a protective factor among Palauan youth at genetic risk for the development of psychotic symptoms. Participants were evaluated for psychotic and other psychiatric symptoms using KSADS-PL. Concurrently, the Youth Self Report was used to assess the perceived quality of family relationships.
Results indicated that adopted adolescents were more likely to develop psychotic symptoms than non-adopted adolescents. However, perceived family relations moderated the association between adoption status and psychotic symptoms, such that adopted adolescents with poorer family relations reported disproportionately higher rates of psychotic symptoms. Family relations also moderated the association between level of genetic risk and psychotic symptoms, independently of adoption status.
Consistent with previous research, adolescents at high genetic risk who reported more positive family relations also reported fewer psychotic symptoms.
Social Psychiatry 11/2009; 45(12):1105-14. · 2.05 Impact Factor
[show abstract][hide abstract] ABSTRACT: Intervention during the pre-psychotic period of illness holds the potential of delaying or even preventing the onset of a full-threshold disorder, or at least of reducing the impact of such a disorder if it does develop. The first step in realizing this aim was achieved more than 10 years ago with the development and validation of criteria for the identification of young people at ultra-high risk (UHR) of psychosis. Results of three clinical trials have been published that provide mixed support for the effectiveness of psychological and pharmacological interventions in preventing the onset of psychotic disorder.
The present paper describes a fourth study that has now been undertaken in which young people who met UHR criteria were randomized to one of three treatment groups: cognitive therapy plus risperidone (CogTher + Risp: n = 43); cognitive therapy plus placebo (CogTher + Placebo: n = 44); and supportive counselling + placebo (Supp + Placebo; n = 28). A fourth group of young people who did not agree to randomization were also followed up (monitoring: n = 78). Baseline characteristics of participants are provided.
The present study improves on the previous studies because treatment was provided for 12 months and the independent contributions of psychological and pharmacological treatments in preventing transition to psychosis in the UHR cohort and on levels of psychopathology and functioning can be directly compared. Issues associated with recruitment and randomization are discussed.
Australian and New Zealand Journal of Psychiatry 10/2009; 43(9):818-29. · 3.29 Impact Factor