Comorbidity within mental disorders: a comprehensive analysis based on 145 990 survey respondents from 27 countries.

AIMS: Epidemiological studies indicate that individuals with one type of mental disorder have an increased risk of subsequently developing other types of mental disorders. This study aimed to undertake a comprehensive analysis of pair-wise lifetime comorbidity across a range of common mental disorders based on a diverse range of population-based surveys. METHODS: The WHO World Mental Health (WMH) surveys assessed 145 990 adult respondents from 27 countries. Based on retrospectively-reported age-of-onset for 24 DSM-IV mental disorders, associations were examined between all 548 logically possible temporally-ordered disorder pairs. Overall and time-dependent hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. Absolute risks were estimated using the product-limit method. Estimates were generated separately for men and women. RESULTS: Each prior lifetime mental disorder was associated with an increased risk of subsequent first onset of each other disorder. The median HR was 12.1 (mean = 14.4; range 5.2-110.8, interquartile range = 6.0-19.4). The HRs were most prominent between closely-related mental disorder types and in the first 1-2 years after the onset of the prior disorder. Although HRs declined with time since prior disorder, significantly elevated risk of subsequent comorbidity persisted for at least 15 years. Appreciable absolute risks of secondary disorders were found over time for many pairs. CONCLUSIONS: Survey data from a range of sites confirms that comorbidity between mental disorders is common. Understanding the risks of temporally secondary disorders may help design practical programs for primary prevention of secondary disorders.

Perceived need and barriers to adolescent mental health care: agreement between adolescents and their parents.

AIMS: Mental disorders cause high burden in adolescents, but adolescents often underutilise potentially beneficial treatments. Perceived need for and barriers to care may influence whether adolescents utilise services and which treatments they receive. Adolescents and parents are stakeholders in adolescent mental health care, but their perceptions regarding need for and barriers to care might differ. Understanding patterns of adolescent-parent agreement might help identify gaps in adolescent mental health care. METHODS: A nationally representative sample of Australian adolescents aged 13-17 and their parents (N = 2310), recruited between 2013-2014, were asked about perceived need for four types of adolescent mental health care (counselling, medication, information and skill training) and barriers to care. Perceived need was categorised as fully met, partially met, unmet, or no need. Cohen's kappa was used to assess adolescent-parent agreement. Multinomial logistic regressions were used to model variables associated with patterns of agreement. RESULTS: Almost half (46.5% (s.e. = 1.21)) of either adolescents or parents reported a perceived need for any type of care. For both groups, perceived need was greatest for counselling and lowest for medication. Identified needs were fully met for a third of adolescents. Adolescent-parent agreement on perceived need was fair (kappa = 0.25 (s.e. = 0.01)), but poor regarding the extent to which needs were met (kappa = -0.10 (s.e. = 0.02)). The lack of parental knowledge about adolescents' feelings was positively associated with adolescent-parent agreement that needs were partially met or unmet and disagreement about perceived need, compared to agreement that needs were fully met (relative risk ratio (RRR) = 1.91 (95% CI = 1.19-3.04) to RRR = 4.69 (95% CI = 2.38-9.28)). Having a probable disorder was positively associated with adolescent-parent agreement that needs were partially met or unmet (RRR = 2.86 (95% CI = 1.46-5.61)), and negatively with adolescent-parent disagreement on perceived need (RRR = 0.50 (95% CI = 0.30-0.82)). Adolescents reported most frequently attitudinal barriers to care (e.g. self-reliance: 55.1% (s.e. = 2.39)); parents most frequently reported that their child refused help (38.7% (s.e. = 2.69)). Adolescent-parent agreement was poor for attitudinal (kappa = -0.03 (s.e. = 0.06)) and slight for structural barriers (kappa = 0.02 (s.e. = 0.09)). CONCLUSIONS: There are gaps in the extent to which adolescent mental health care is meeting the needs of adolescents and their parents. It seems important to align adolescents' and parents' needs at the beginning and throughout treatment and to improve communication between adolescents and their parents. Both might provide opportunities to increase the likelihood that needs will be fully met. Campaigns directed towards adolescents and parents need to address different barriers to care. For adolescents, attitudinal barriers such as stigma and mental health literacy require attention.

The risk of developing major depression among individuals with subthreshold depression: a systematic review and meta-analysis of longitudinal cohort studies.

BACKGROUND: Studies have consistently shown that subthreshold depression is associated with an increased risk of developing major depression. However, no study has yet calculated a pooled estimate that quantifies the magnitude of this risk across multiple studies. METHODS: We conducted a systematic review to identify longitudinal cohort studies containing data on the association between subthreshold depression and future major depression. A baseline meta-analysis was conducted using the inverse variance heterogeneity method to calculate the incidence rate ratio (IRR) of major depression among people with subthreshold depression relative to non-depressed controls. Subgroup analyses were conducted to investigate whether IRR estimates differed between studies categorised by age group or sample type. Sensitivity analyses were also conducted to test the robustness of baseline results to several sources of study heterogeneity, such as the case definition for subthreshold depression. RESULTS: Data from 16 studies (n = 67 318) revealed that people with subthreshold depression had an increased risk of developing major depression (IRR = 1.95, 95% confidence interval 1.28-2.97). Subgroup analyses estimated similar IRRs for different age groups (youth, adults and the elderly) and sample types (community-based and primary care). Sensitivity analyses demonstrated that baseline results were robust to different sources of study heterogeneity. CONCLUSION: The results of this study support the scaling up of effective indicated prevention interventions for people with subthreshold depression, regardless of age group or setting.

A profile of Australian mental health carers, their caring role and service needs: results from the 2012 Survey of Disability, Ageing and Carers.

AIMS: Planning mental health carer services requires information about the number of carers, their characteristics, service use and unmet support needs. Available Australian estimates vary widely due to different definitions of mental illness and the types of carers included. This study aimed to provide a detailed profile of Australian mental health carers using a nationally representative household survey. METHODS: The number of mental health carers, characteristics of carers and their care recipients, caring hours and tasks provided, service use and unmet service needs were derived from the national 2012 Survey of Disability, Ageing and Carers. Co-resident carers of adults with a mental illness were compared with those caring for people with physical health and other cognitive/behavioural conditions (e.g., autism, intellectual disability, dementia) on measures of service use, service needs and aspects of their caring role. RESULTS: In 2012, there were 225 421 co-resident carers of adults with mental illness in Australia, representing 1.0% of the population, and an estimated further 103 813 mental health carers not living with their care recipient. The majority of co-resident carers supported one person with mental illness, usually their partner or adult child. Mental health carers were more likely than physical health carers to provide emotional support (68.1% v. 19.7% of carers) and less likely to assist with practical tasks (64.1% v. 86.6%) and activities of daily living (31.9% v. 48.9%). Of co-resident mental health carers, 22.5% or 50 828 people were confirmed primary carers - the person providing the most support to their care recipient. Many primary mental health carers (37.8%) provided more than 40 h of care per week. Only 23.8% of primary mental health carers received government income support for carers and only 34.4% received formal service assistance in their caring role, while 49.0% wanted more support. Significantly more primary mental health than primary physical health carers were dissatisfied with received services (20.0% v. 3.2%), and 35.0% did not know what services were available to them. CONCLUSIONS: Results reveal a sizable number of mental health carers with unmet needs in the Australian community, particularly with respect to financial assistance and respite care, and that these carers are poorly informed about available supports. The prominence of emotional support and their greater dissatisfaction with services indicate a need to better tailor carer services. If implemented carefully, recent Australian reforms including the Carer Gateway and National Disability Insurance Scheme hold promise for improving mental health carer supports.

Deterioration of visuospatial associative memory following a first psychotic episode: a long-term follow-up study.

BACKGROUND: Cognitive deficits are a core feature of schizophrenia, and impairments in most domains are thought to be stable over the course of the illness. However, cross-sectional evidence indicates that some areas of cognition, such as visuospatial associative memory, may be preserved in the early stages of psychosis, but become impaired in later established illness stages. This longitudinal study investigated change in visuospatial and verbal associative memory following psychosis onset. METHODS: In total 95 first-episode psychosis (FEP) patients and 63 healthy controls (HC) were assessed on neuropsychological tests at baseline, with 38 FEP and 22 HCs returning for follow-up assessment at 5-11 years. Visuospatial associative memory was assessed using the Cambridge Neuropsychological Test Automated Battery Visuospatial Paired-Associate Learning task, and verbal associative memory was assessed using Verbal Paired Associates subtest of the Wechsler Memory Scale - Revised. RESULTS: Visuospatial and verbal associative memory at baseline did not differ significantly between FEP patients and HCs. However, over follow-up, visuospatial associative memory deteriorated significantly for the FEP group, relative to healthy individuals. Conversely, verbal associative memory improved to a similar degree observed in HCs. In the FEP cohort, visuospatial (but not verbal) associative memory ability at baseline was associated with functional outcome at follow-up. CONCLUSIONS: Areas of cognition that develop prior to psychosis onset, such as visuospatial and verbal associative memory, may be preserved early in the illness. Later deterioration in visuospatial memory ability may relate to progressive structural and functional brain abnormalities that occurs following psychosis onset.

A systematic review and meta-regression of the prevalence and incidence of perinatal depression.

BACKGROUND: Major Depressive Disorder (MDD) is a leading cause of the disease burden for women of childbearing age, but the burden of MDD attributable to perinatal depression is not yet known. There has been little effort to date to systematically review available literature and produce global estimates of prevalence and incidence of perinatal depression. Enhanced understanding will help to guide resource allocation for screening and treatment. METHODS: A systematic literature review using the databases PsycINFO and PubMed returned 140 usable prevalence estimates from 96 studies. A random-effects meta-regression was performed to determine sources of heterogeneity in prevalence estimates between studies and to guide a subsequent random-effects meta-analysis. RESULTS: The meta-regression explained 31.1% of the variance in prevalence reported between studies. Adjusting for the effects of all other variables in the model, prevalence derived using symptom scales was significantly higher than prevalence derived using diagnostic instruments (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.3-2.0). Additionally, prevalence was significantly higher in women from low and middle income countries compared to women from high income countries (OR 1.8, 95% CI 1.4-2.2). The overall pooled prevalence was 11.9% of women during the perinatal period (95% CI 11.4-12.5). There were insufficient data to calculate pooled incidence. LIMITATIONS: Studies in low income countries were especially scarce in this review, demonstrating a need for more epidemiological research in those regions. CONCLUSIONS: Perinatal depression appears to impose a higher burden on women in low- and middle-income countries. This review contributes significantly to the epidemiological literature on the disorder.

Gender-related patterns and determinants of recent help-seeking for past-year affective, anxiety and substance use disorders: findings from a national epidemiological survey.

AIMS: To examine: (1) gender-specific determinants of help-seeking for mental health, including health professional consultation and the use of non-clinical support services and self-management strategies (SS/SM) and; (2) gender differences among individuals with unmet perceived need for care. METHOD: Analyses focused on 689 males and 1075 females aged 16-85 years who met ICD-10 criteria for a past-year affective, anxiety or substance use disorder in an Australian community-representative survey. Two classifications of help-seeking for mental health in the previous year were created: (1) no health professional consultation or SS/SM, or health professional consultation, or SS/SM only, and; (2) no general practitioner (GP) or mental health professional consultation, or GP only consultation, or mental health professional consultation. Between- and within-gender help-seeking patterns were explored using multinomial logistic regression models. Characteristics of males and females with unmet perceived need for care were compared using chi-square tests. RESULTS: Males with mental or substance use disorders had relatively lower odds than females of any health professional consultation (adjusted odds ratio [AOR] = 0.46), use of SS/SM only (AOR = 0.59), and GP only consultation (AOR = 0.29). Notably, males with severe disorders had substantially lower odds than females of any health professional consultation (AOR = 0.29) and GP only consultation (AOR = 0.14). Most correlates of help-seeking were need-related. Many applied to both genders (e.g., severity, disability, psychiatric comorbidity), although some were male-specific (e.g., past-year reaction to a traumatic event) or female-specific (e.g., past-year affective disorder). Certain enabling and predisposing factors increased the probability of health professional consultation for both genders (age 30+ years) or for males (unmarried, single parenthood, reliance on government pension). Males with unmet perceived need for care were more likely to have experienced a substance use disorder and to want medicine or tablets or social intervention, whereas their females peers were more likely to have experienced an anxiety disorder and to want counselling or talking therapy. For both genders, attitudinal/knowledge barriers to receiving the types of help wanted (e.g., not knowing where to get help) were more commonly reported than structural barriers (e.g., cost). CONCLUSIONS: Findings suggest a need to address barriers to help-seeking in males with severe disorders, and promote GP consultation. Exploring gender-specific attitudinal/knowledge barriers to receiving help, and the types of help wanted, may assist in designing interventions to increase consultation. Mental health promotion/education efforts could incorporate information about the content and benefits of evidence-based treatments and encourage males to participate in other potentially beneficial actions (e.g., physical activity).

Intersectoral policy for severe and persistent mental illness: review of approaches in a sample of high-income countries.

BACKGROUND: It is increasingly recognised that intersectoral linkages between mental health and other health and support sectors are essential for providing effective care for individuals with severe and persistent mental illness. The extent to which intersectoral collaboration and approaches to achieve it are detailed in mental health policy has not yet been systematically examined. METHODS: Thirty-eight mental health policy documents from 22 jurisdictions in Australia, New Zealand, the United Kingdom, Ireland and Canada were identified via a web search. Information was extracted and synthesised on: the extent to which intersectoral collaboration was an objective or guiding principle of policy; the sectors acknowledged as targets for collaboration; and the characteristics of detailed intersectoral collaboration efforts. RESULTS: Recurring themes in objectives/guiding principles included a whole of government approach, coordination and integration of services, and increased social and economic participation. All jurisdictions acknowledged the importance of intersectoral collaboration, particularly with employment, education, housing, community, criminal justice, drug and alcohol, physical health, Indigenous, disability, emergency and aged care services. However, the level of detail provided varied widely. Where detailed strategies were described, the most common linkage mechanisms were joint service planning through intersectoral coordinating committees or liaison workers, interagency agreements, staff training and joint service provision. CONCLUSIONS: Sectors and mechanisms identified for collaboration were largely consistent across jurisdictions. Little information was provided about strategies for accountability, resourcing, monitoring and evaluation of intersectoral collaboration initiatives, highlighting an area for further improvement. Examples of collaboration detailed in the policies provide a useful resource for other countries.

Estimating remission from untreated major depression: a systematic review and meta-analysis.

BACKGROUND: Few studies have examined spontaneous remission from major depression. This study investigated the proportion of prevalent cases of untreated major depression that will remit without treatment in a year, and whether remission rates vary by disorder severity. METHOD: Wait-list controlled trials and observational cohort studies published up to 2010 with data describing remission from untreated depression at ≤ 2-year follow-up were identified. Remission was defined as rescinded diagnoses or below threshold scores on standardized symptom measures. Nineteen studies were included in a regression model predicting the probability of 12-month remission from untreated depression, using logit transformed remission proportion as the dependent variable. Covariates included age, gender, study type and diagnostic measure. RESULTS: Wait-listed compared to primary-care samples, studies with longer follow-up duration and older adult compared to adult samples were associated with lower probability of remission. Child and adolescent samples were associated with higher probability of remission. Based on adult samples recruited from primary-care settings, the model estimated that 23% of prevalent cases of untreated depression will remit within 3 months, 32% within 6 months and 53% within 12 months. CONCLUSIONS: It is undesirable to expect 100% treatment coverage for depression, given many will remit before access to services is feasible. Data were drawn from consenting wait-list and primary-care samples, which potentially over-represented mild-to-moderate cases of depression. Considering reported rates of spontaneous remission, a short untreated period seems defensible for this subpopulation, where judged appropriate by the clinician. Conclusions may not apply to individuals with more severe depression.

Predictors of suicide-related behaviors during treatment following a first episode of psychosis: the contribution of baseline, past, and recent factors.

BACKGROUND: Suicide-related behaviors (suicide attempts and suicides) are common in the early phase of psychotic disorders. Studies have examined risk factors among baseline and historical (i.e., past) variables, yet little is known about recent characteristics that increase suicide risk during treatment for first-episode psychosis (FEP). This study had two aims: first, to determine the relative importance of baseline, past, and recent variables to the prediction of suicide-related behaviors in patients with FEP; second, to identify recent characteristics that exert most influence on suicide risk levels and which could become foci of preventive interventions. METHODS: This was a case-control study of 180 patients from a cohort entering a specialist FEP service between 1/12/2002 and 30/11/2005. Data for 72 cases and 108 matched controls were obtained via medical record audit. Multivariate logistic regression models assessed the contribution of baseline, past, and recent domains. Suicide attempt or suicide during treatment was the outcome variable. RESULTS: The strongest risk factors for suicide-related behaviors were: baseline depressive symptoms, baseline suicidal ideation/intent, past negative events, past non-suicidal self-injurious behavior, recent negative events, recent depressive symptoms, and recent non-suicidal self-injurious behavior. However, when these were entered into a hierarchical logistic regression model, only recent non-suicidal self-injurious behavior (AOR=72.96, p<0.001), and recent negative events (AOR=1.90, p=0.003) remained significant predictors. The final model accurately classified 75.5% of cases and 89.2% of controls, and explained 72.0% of variance in the suicide attempt status. CONCLUSIONS: Since recent negative events and recent non-suicidal self-injurious behavior were the strongest predictors of suicide-related behaviors during treatment for FEP, psychiatric services could consider incorporating psychosocial interventions addressing affect regulation, interpersonal effectiveness, stress management and problem solving, alongside case management and pharmacotherapy, to help to reduce the rates of suicide attempts and suicides in first-episode patients.

Manganese exposure and cognitive deficits: a growing concern for manganese neurotoxicity.

This symposium comprised five oral presentations dealing with recent findings on Mn-related cognitive and motor changes from epidemiological studies across the life span. The first contribution highlighted the usefulness of functional neuroimaging of the central nervous system (CNS) to evaluate cognitive as well as motor deficits in Mn-exposed welders. The second dealt with results of two prospective studies in Mn-exposed workers or welders showing that after decrease of Mn exposure the outcome of reversibility in adverse CNS effects may differ for motor and cognitive function and, in addition the issue of plasma Mn as a reliable biomarker for Mn exposure in welders has been addressed. The third presentation showed a brief overview of the results of an ongoing study assessing the relationship between environmental airborne Mn exposure and neurological or neuropsychological effects in adult Ohio residents living near a Mn point source. The fourth paper focused on the association between blood Mn and neurodevelopment in early childhood which seems to be sensitive to both low and high Mn concentrations. The fifth contribution gave an overview of six studies indicating a negative impact of excess environmental Mn exposure from air and drinking water on children's cognitive performance, with special attention to hair Mn as a potential biomarker of exposure. These studies highlight a series of questions about Mn neurotoxicity with respect to cognitive processes, forms and routes of exposure, adequate biomarkers of exposure, gender differences, susceptibility and exposure limits with regard to age.

Road to full recovery: longitudinal relationship between symptomatic remission and psychosocial recovery in first-episode psychosis over 7.5 years.

BACKGROUND: In recent years there has been increasing interest in functional recovery in the early phase of schizophrenia. Concurrently, new remission criteria have been proposed and several studies have examined their clinical relevance for prediction of functional outcome in first-episode psychosis (FEP). However, the longitudinal interrelationship between full functional recovery (FFR) and symptom remission has not yet been investigated. This study sought to: (1) examine the relationships between FFR and symptom remission in FEP over 7.5 years; (2) test two different models of the interaction between both variables. METHOD: Altogether, 209 FEP patients treated at a specialized early psychosis service were assessed at baseline, 8 months, 14 months and 7.5 years to determine their remission of positive and negative symptoms and functional recovery. Multivariate logistic regression and path analysis were employed to test the hypothesized relationships between symptom remission and FFR. RESULTS: Remission of both positive and negative symptoms at 8-month follow-up predicted functional recovery at 14-month follow-up, but had limited value for the prediction of FFR at 7.5 years. Functional recovery at 14-month follow-up significantly predicted both FFR and remission of negative symptoms at 7.5 years, irrespective of whether remission criteria were simultaneously met. The association remained significant after controlling for baseline prognostic indicators. CONCLUSIONS: These findings provided support for the hypothesis that early functional and vocational recovery plays a pivotal role in preventing the development of chronic negative symptoms and disability. This underlines the need for interventions that specifically address early psychosocial recovery.

Prediction of a single psychotic episode: a 7.5-year, prospective study in first-episode psychosis.

BACKGROUND: Around 20% of patients who suffer from psychosis will experience a single psychotic episode (SPE), but relatively little is known about the characteristics and predictors for this group of patients. This study sought to: 1) characterise the subgroup of first-episode psychosis (FEP) patients who experienced a SPE over a 7.5-year follow-up; and 2) to identify significant predictors for this subgroup independent of potential confounders. METHODS: A representative sample of 413 FEP patients treated at a specialist early psychosis service were assessed at baseline and followed-up for 7.5 years. Binary logistic regression models were employed to investigate univariate and adjusted associations between baseline predictors and experiencing a SPE. Results were adjusted for the influence of known prognostic factors for psychosis. RESULTS: Follow-up data was available for 274 participants. Forty-six (16.5%) achieved clinical remission and experienced no recurrence over the follow-up period. Duration of untreated psychosis (DUP) shorter than 60 days (OR=3.89, p=0.007), more rapid response to antipsychotic treatment (OR=0.33, p=0.019) and no parental loss (OR=5.25, p=0.045) significantly predicted a SPE. The association remained significant after controlling for potential confounders. CONCLUSIONS: Early treatment (within two months of onset of psychotic symptoms) and social support significantly reduce vulnerability to subsequent psychotic episodes. Future studies need to investigate the interplay between biological factors (i.e. sensitized dopaminergic system), environmental variables (i.e. exposure to trauma, stigma and discrimination), and psychological attributes (i.e. cognitive schemata) in order to elucidate the processes underlying the vulnerability to recurrent psychotic episodes.

Suicide attempt in first-episode psychosis: a 7.4 year follow-up study.

BACKGROUND: Individuals with first-episode psychosis demonstrate high rates of suicide attempt (SA). AIMS: 1) To examine the prevalence of, and risk factors for, SA in a first-episode psychosis (FEP) cohort over a 7.4 year follow-up period. 2) To investigate differences between single versus multiple suicide attempters. METHODS: This study reports baseline and follow-up data from a naturalistic, prospective follow-up of 413 FEP patients treated at a specialist early psychosis centre. Assessments were conducted at treatment entry, initial symptom remission or stabilization, and long term follow-up. Binary logistic regression models were used to assess unadjusted and adjusted associations between early illness and sociodemographic characteristics and two outcome measures: any SA during follow-up; and multiple SAs. RESULTS: Follow-up data were available for 282 participants. Sixty-one (21.6%) made a suicide attempt over the follow-up period, including 12 successful suicides. The following baseline risk factors increased the risk of any SA: history of self-harm (OR=4.27; p<0.001), suicidal tendencies (OR=2.30; p=0.022), being depressed for >50% of the initial psychotic episode (OR=2.49; p=0.045), and hopelessness (OR=2.03; p=0.030). History of problem alcohol use increased the risk of multiple SAs (OR=4.43; 95% CI (1.05-18.7); p=0.043). DISCUSSION: The prevalence of suicide attempt in this study exceeds reports from short-term FEP studies but is comparable to longer term follow-up studies, indicating that risk remains elevated for at least 7 years following commencement of treatment. The key predictor of future suicide attempt was previous self-harm, indicating that interventions for self-harm are required.

The stability of correlates of labour force activity.

OBJECTIVE: To investigate the stability of correlates of labour force activity among people with affective and anxiety disorders, compared with healthy adults, between 1998 and 2003. METHOD: Secondary analyses of multi-stage probability samples of community residents (n(1998)=37,580 and n(2003)=36,088) obtained from repeat administrations of an Australian population survey. RESULTS: Proportionally, fewer people with affective or anxiety disorders were employed compared with well controls. Extent of employment restrictions, sex, age left school, country of birth, age and educational attainment were strong correlates of labour force participation and current employment. These effects were stable despite improved labour market conditions in 2003. CONCLUSION: These results can inform decisions about access to substantial forms of employment assistance. Subgroups of people with anxiety and depression, with severe employment restrictions, low education, low language proficiency, aged 15-24 years, or aged 55 years or more, may require greater access to substantial employment assistance.

Prevalence and correlates of comorbidity 8 years after a first psychotic episode.

OBJECTIVE: While rates and correlates of comorbidity have been investigated in the early course of psychosis, little is known about comorbidity in the medium-to-longer term or its relationship with outcome. METHOD: A total of 182 first-episode psychosis (FEP) patients who met DSM-IV criteria for a current psychotic disorder 8 years after index presentation were grouped according to concurrent comorbidity [no concurrent axis I disorder; concurrent substance use disorder (SUD); other concurrent axis I disorder; concurrent SUD and other axis I disorder]. Outcomes were compared between groups controlling for relevant covariates. RESULTS: As much as 39% met criteria for one or more concurrent axis 1 diagnoses. Comorbidity was associated with greater severity of general psychopathology, but not with measures of functioning, treatment or negative symptoms. CONCLUSION: Specific combinations of comorbid disorders may influence patterns of psychotic symptomatology. Routine examination of axis I disorders is warranted in the ongoing management of psychosis.

Treated incidence of first-episode psychosis in the catchment area of EPPIC between 1997 and 2000.

OBJECTIVE: To identify the treated incidence of psychosis in catchment of the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia. METHOD: Cases were aged 15-29 years with a first episode of a psychotic disorder accepted into EPPIC between 1997 and 2000. Age- and sex-specific incidence rates per 10,000 person-years were calculated in 5 year age bands. Rate ratios were used for age group comparisons. RESULTS: The age-specific treated incidence of first-episode psychosis in 15-29-year old individuals was 16.7 per 10,000 person-years in males, and 8.1 per 10,000 person-years in females. The incidence was highest in 20-24-year-old males and in 15-19-year-old females. For both sexes, incidence rates were significantly lower in the 25-29-year age group. CONCLUSIONS: The incidence of psychosis in the catchment of EPPIC was higher than previously reported, especially in female teenagers. Peak rates in 15-24 year olds suggest a youth model approach to early psychosis may be indicated.

Independent detectors for expansion and rotation, and for orthogonal components of deformation.

It is well known that optic flow--the smooth transformation of the retinal image experienced by a moving observer--contains valuable information about the three-dimensional layout of the environment. From psychophysical and neurophysiological experiments, specialised mechanisms responsive to components of optic flow (sometimes called complex motion) such as expansion and rotation have been inferred. However, it remains unclear (a) whether the visual system has mechanisms for processing the component of deformation and (b) whether there are multiple mechanisms that function independently from each other. Here, we investigate these issues using random-dot patterns and a forced-choice subthreshold summation technique. In experiment 1, we manipulated the size of a test region that was permitted to contain signal and found substantial spatial summation for signal components of translation, expansion, rotation, and deformation embedded in noise. In experiment 2, little or no summation was found for the superposition of orthogonal pairs of complex motion patterns (eg expansion and rotation), consistent with probability summation between pairs of independent detectors. Our results suggest that optic-flow components are detected by mechanisms that are specialised for particular patterns of complex motion.

Is optic flow used to guide walking while wearing a displacing prism?

Rushton et al (1998 Current Biology 8 1191 - 1194) recently showed that walkers wearing displacing prisms follow curved trajectories determined by the perceived direction of their target. This suggests that optic flow is not important in guidance, since flow cues are unaffected by the prism and should allow a straight, direct trajectory. We replicated Rushton et al's result but also tried to rule out an important artifact associated with the prism. Prisms restrict the field of view and, particularly, access to the foreground optic flow that is likely to be important in providing guidance cues. We found that performance did not improve when walkers directed their gaze to include the foreground flow, suggesting that Rushton et al's results were not due to this artifact. On the other hand, performance did reliably improve when subjects reduced their viewing height by crawling towards the target. This improvement may be due to coarsening of the visual texture or to increased salience of alignment and motion-parallax cues. Whatever its cause, the improvement demonstrates that guidance is not determined only by perceived target direction and that, under some conditions, flow may be important.