Prevalence of treatment-resistant schizophrenia among people with early psychosis and its clinical and demographic correlates.

OBJECTIVE: The prevalence of treatment-resistant schizophrenia (TRS) among people with first-episode schizophrenia (FES) has been sub-optimally researched in Australia and internationally. We evaluated the prevalence of TRS among a cohort of FES patients and compared their sociodemographic and clinical characteristics to those with FES who were treatment responsive. METHODS: Over 2 years, we collated demographic, clinical and treatment-related data of all patients with ICD-10 (International Classification of Diseases, Tenth revision) diagnosis of schizophrenia who were active in October 2020 at four early psychosis intervention services (EPIS) in Western Australia. We used a modified version of Suzuki et al. criteria to diagnose TRS. The data were analysed utilising descriptive statistics, the Mann-Whitney U test, Student's t-test and the False-Discovery Rate method. RESULTS: The prevalence of TRS among the 167 patients diagnosed with FES was 41.3%, and the rates did not differ significantly between the services (p = 0.955). Those in the TRS group were less independent (p = 0.011), had more prolonged unemployment (p = 0.014) and were more likely to be on disability pension (p = 0.011) compared to the treatment responsive group. Furthermore, they had greater severity of symptoms (p = 0.002), longer duration of psychiatric symptoms (p = 0.019), more hospitalisations (p = 0.002) and longer cumulative admission durations (p = 0.002). CONCLUSIONS: Our study revealed that treatment resistance to antipsychotics is prevalent among people with FES managed at EPIS. Notably, it establishes an association between TRS and heightened clinical severity and psychosocial and treatment burden. These findings highlight the imperative for early detection of treatment resistance and timely and specialised interventions for this condition in mental health services.

Access to urban community mental health services: does geographical distance play a role?

PURPOSE: Mental health challenges are a pressing concern in Australia, which account for a significant portion of the disease burden and economic costs, yet a substantial number of those affected do not utilise necessary professional support. This study evaluates distance decay effect on adults' community mental health services in North Metropolitan Western Australia and explores factors influencing service use. METHODS: Data were extracted from the Mental Health Information Data Collections including the records of consumers receiving face-to-face services from the Community Mental Health Clinics in the North Metro Health Service during March 2022 to March 2023. Additionally, socio-demographic information for each suburb and population data were obtained from the Australian Bureau of Statistics. The distance between residential suburbs and clinic locations was calculated. Descriptive statistics were used to describe the characteristics of the study population. A hierarchical linear regression analysis was used to explore whether the distance of suburb to the nearest community clinic was related to service utilisation. RESULTS: A total of 3,453 consumers received direct services across the North Metro Health Service Community Mental Health Clinics. Findings highlighted the impact of proximity to clinics on service utilisation, with suburbs closer to clinics exhibiting higher visit rates (p = 0.004). The data also showed a strong positive correlation between gender (percentage of females in the suburb) and living in socially and economically disadvantaged areas with consumer visits per thousand residents. CONCLUSIONS: These findings underscore the importance of addressing accessibility barriers and tailoring mental health services to meet the diverse needs of the community.

Aripiprazole in young people with early psychosis: a systematic review and meta-analysis of weight gain.

OBJECTIVE: Aripiprazole is often prescribed to young people, although there remain unanswered questions about its effects on weight gain. This study undertook a meta-analysis of weight gain occurring in young people with early psychosis who were prescribed aripiprazole. METHOD: A systematic search was conducted for studies reporting on aripiprazole and weight change in young people with a psychotic disorder. A meta-analysis integrated the data into an estimate of effect size. RESULTS: Eleven studies met the inclusion criteria amounting to 886 participants (mean age 18 years). The results showed significant weight gain averaging 2.7 kg. These increases were associated with a longer duration of exposure to aripiprazole but not a higher dosage. CONCLUSIONS: The results highlight the importance of regular patient monitoring and the early implementation of interventions to manage antipsychotic-related weight gain.

Mental health recovery and physical health outcomes in psychotic illness: Longitudinal data from the Western Australian survey of high impact psychosis catchments.

OBJECTIVE: There is a dearth of longitudinal data on outcomes in prevalent cases of psychotic illness across a range of ages and levels of chronicity. Our aim was to describe changes over time in mental and physical health outcomes, as well as patterns of service utilisation that may have influenced outcomes, in a representative prevalence sample of 641 Western Australians with a psychotic illness who, at Wave 1, were part of the National Survey of High Impact Psychosis. METHODS: In Wave 1 (2010, 2012), a two-phase design was employed to ensure representativeness: Phase 1 psychosis screening took place in public mental health and non-government organisation services, while, in Phase 2, a randomised sample was interviewed. In Wave 2, 380/641 (59%) of participants were re-interviewed, with interviews staggered between 2013 and 2016 (follow-up time: 2.3-5.6 years). Data collection covered mental and physical health, functioning, cognition, social circumstances and service utilisation. Mental health outcomes were categorised as symptomatic, functional and personal recovery. Physical health outcomes covered metabolic syndrome and its component criteria. RESULTS: In mental health, there were encouraging improvements in symptom profiles, variable change in functional recovery and some positive findings for personal recovery, but not quality of life. Participants ranked physical health second among challenges. Metabolic syndrome had increased significantly. While treatment for underlying cardiovascular risk conditions had improved, rates of intervention were still very low. More people were accessing general practices and more frequently, but there were sharp and significant declines in access to community rehabilitation, psychosocial interventions and case management. CONCLUSION: Although we observed some positive outcomes over time, the sharp decline in access to evidence-based interventions such as community rehabilitation, psychosocial interventions and case management is of great concern and augurs poorly for recovery-oriented practice. Changes in service utilisation appear to have influenced the patterns found.

The time course of psychotic symptom side effects of ketamine in the treatment of depressive disorders: a systematic review and meta-analysis.

OBJECTIVE: Ketamine is a potential rapid-acting treatment for depression. Studies have suggested that the side effects are minimal and temporary, but the psychotic symptom side effects have yet to be fully examined. This study investigated whether ketamine infusion in the treatment of mood disorders is associated with increases in positive symptoms and whether these symptom effects endure over time. METHODS: A systematic review and meta-analysis of studies of ketamine in the treatment of depression. Embase and Medline databases were searched for studies including (a) participants with major affective disorders, (b) 0.4 or 0.5 mg intravenously administered ketamine, (c) measurement of positive symptoms using BPRS+, and (d) a within-subject repeated-measures design with participants serving as their own baseline. RESULTS: Seventeen studies met the inclusion criteria, comprising 458 participants. The meta-analyses examined symptom change occurring within the first 4 h, after 1 day, and after 3 days. Results showed significant BPRS+ increases within the first 30-60 min in 72% of studies, followed by a return to baseline levels. CONCLUSION: Peak symptom change occurred within the first hour post infusion. There are limited data to determine if ketamine is safe in the longer term, but there were no indications that psychotic symptoms re-occurred after the first hour and in the days following administration.

Emergency department mental health presentations before and during the COVID-19 outbreak in Western Australia.

OBJECTIVE: Coronavirus (COVID-19) has led to high levels of psychological distress in the community. This study aimed to examine whether emergency departments (EDs) also recorded a rise in mental health presentations. METHOD: Changes in the number, and type, of mental health presentations to Western Australia EDs were examined between January and May 2020, and compared to 2019. RESULTS: Data showed an unexpected decrease in the number of mental health presentations, compared to 2019, which was temporally coincident with the rise in local COVID-19 cases. Presentations for anxiety and panic symptoms, and social and behavioural issues, increased by 11.1% and 6.5%, respectively, but suicidal and self-harm behaviours decreased by 26%. CONCLUSION: A rise in local COVID-19 cases was associated with a decrease in mental health presentations to EDs. This has important implications for the planning and provision of healthcare services in the current pandemic.

Sexual health and sexual trauma in women with severe mental illness: An exploratory survey of Western Australian community mental health services.

Australian women attending community mental health services were surveyed to determine the relationship between sexual trauma, sexual activity, and sexual health seeking behaviors. Self-reported history of "forced sex" was 58.4% (n = 122 out of 220). Latent class analysis revealed a three-class model: "sexually active and health seeking," "low sexual activity and health seeking" and "low sexual activity and not health seeking." An association with general practitioner engagement and sexual health seeking behaviors was found. Rates of self-reported sexual trauma reinforce the need for screening and trauma informed care. Groupings may reflect different aspects of recovery associated with sexual health behaviors.

Comorbid Anxiety and Depression and Their Impact on Cardiovascular Disease in Type 2 Diabetes: The Fremantle Diabetes Study Phase II.

BACKGROUND: The aims were to determine whether anxious depression, defined by latent class analysis (LCA), predicts cardiovascular outcomes in type 2 diabetes and to compare the predictive power of anxious depression with Diagnostic & Statistical Manual Versions IV and 5 (DSM-IV/5) categories of depression and generalized anxiety disorder (GAD). METHODS: Prospective observational study of 1,337 type 2 participants. Baseline assessment with the 9-item Patient Health Questionnaire and the GAD Scale; LCA-defined groups with minor or major anxious depression based on anxiety and depression symptoms. Cox modeling used to compare the independent impact of: (1) LCA anxious depression, (2) DSM-IV/5 depression, (3) GAD on incident cardiovascular events and deaths after 4 years. RESULTS: LCA minor and major anxious depression was present in 21.9 and 7.8% of participants, respectively, DSM-IV/5 minor and major depression in 6.2 and 6.1%, respectively, and GAD in 4.8%. There were 110 deaths, 31 cardiovascular deaths, and 199 participants had incident cardiovascular events. In adjusted models, minor anxious depression (Hazard ratio (95% confidence intervals): 1.70 (1.15-2.50)) and major anxious depression (1.90 (1.11-3.25)) predicted incident cardiovascular events and major anxious depression also predicted cardiovascular mortality (4.32 (1.35-13.86)). By comparison, incident cardiovascular events were predicted by DSM-IV/5 major depression (2.10 (1.22-3.62)) only and cardiovascular mortality was predicted by both DSM-IV/5 major depression (3.56 (1.03-12.35)) and GAD (5.92 (1.84-19.08)). CONCLUSIONS: LCA-defined anxious depression is more common than DSM-IV/5 categories and is a strong predictor of cardiovascular outcomes in type 2 diabetes. These data suggest that this diagnostic scheme has predictive validity and clinical relevance.

Screening for the metabolic syndrome in Australia: a national survey of psychiatrists' attitudes and reported practice in patients prescribed antipsychotic drugs.

OBJECTIVE: To investigate current reported psychiatric practice in relation to screening for the metabolic syndrome in patients prescribed antipsychotic drugs within Australia. METHOD: A postal survey of all Fellows of the Royal Australian and New Zealand College of Psychiatrists. A 28-item questionnaire inquired into different aspects of screening and monitoring for metabolic syndrome in patients on antipsychotic medication. RESULTS: Of 3123 questionnaires sent, 955 were returned. Of respondents, 55% had no established metabolic monitoring protocol or guidelines in their work place, with 13% saying they did not know what to monitor to detect metabolic syndrome. Altogether, 76% reported there was no reliable system in place to remind them when to monitor. Fewer than 50% of respondents routinely check weight, fasting glucose or lipids in their patients on antipsychotics and under than 30% checked blood pressure. Waist circumference was routinely checked in fewer than 7% of patients. Basic monitoring equipment was reported unavailable in more than 50% of clinical settings. However, more than 80% of respondents considered monitoring for metabolic syndrome to be their responsibility and 83% felt they had a medicolegal obligation in this respect. CONCLUSIONS: Routine screening for metabolic syndrome in patients on antipsychotic agents, by Australian psychiatrists, is inadequate. Interventions to improve screening rates need to be developed, implemented and evaluated.

The impact of emotional distress on motor blocks and festination in Parkinson's disease.

Recent studies suggest that depression and anxiety in patients with Parkinson's disease may predispose them to freezing. Although festination is also frequent, the association with emotional disorders has not been examined. The aim of the authors was to clarify the association between freezing and festination with anxiety, depressive disorders, and emotional distress. The authors examined a consecutive series of 95 patients with Parkinson's disease using comprehensive psychiatric assessments and a new instrument specifically designed to assess the severity of freezing, festination, and emotional distress (Motor Blocks and Festination Scale). All patients were assessed with the Motor Blocks and Festination Scale, the Mini International Neuropsychiatric Interview, and scales to measure the severity of mood and anxiety disorders. A linear regression analysis showed that both motor blocks and festination were significantly associated with emotional distress and deficits on activities of daily living. Conversely, there was no significant association between motor blocks or festination and generalized anxiety disorder, panic disorder, agoraphobia, social phobia, or depression. Motor blocks and festination are significantly associated with emotional distress, but no significant associations were found with anxiety or affective disorders.

Anxiety has specific syndromal profiles in Parkinson disease: a data-driven approach.

BACKGROUND: Anxiety symptoms are common in Parkinson disease (PD). Recent evidence suggests that anxiety syndromes as encountered in clinical practice may not correspond to the DSM-IV classification of anxiety disorders. OBJECTIVE: To examine the syndromal pattern of the anxiety spectrum in a large series of patients with PD, as determined with a data-driven approach using latent class analysis (LCA). METHODS: 342 patients with PD were recruited from referrals to movement disorders or psychiatry clinics at six tertiary centers. Participants were assessed with a structured psychiatric interview and specific scales rating the severity of anxiety, depression, cognition and parkinsonism. The main outcome measure was classes of patients with a specific syndromal profile of anxiety symptoms based on LCA. RESULTS: LCA identified four classes that were interpreted as "no anxiety or depression", "episodic anxiety without depression", "persistent anxiety with depression", and "both persistent and episodic anxiety with depression". Symptoms of persistent anxiety were almost invariably associated with symptoms of depression. There were significant differences between classes in terms of history of depression and anxiety, use of psychoactive medication, and on the Mentation and Complications sections of the Unified Parkinson Disease Rating Scale. CONCLUSIONS: Patients with PD show different syndromic profiles of anxiety that do not align with the symptom profiles represented by DSM-IV anxiety disorders and major depression. Accordingly, DSM-IV criteria for anxiety disorders may not be clinically useful in PD. The different classes identified here provide empirically validated phenotypes for future research.

Prevalence and nature of antipsychotic polypharmacy among inpatients with schizophrenia spectrum disorders at an Australian mental health service.

OBJECTIVE: Though antipsychotic polypharmacy (APP) is widely utilised in many clinical settings for the treatment of people with schizophrenia, the extent of this practice varies considerably between different regions, countries and clinical settings. Studies from Australasia exploring the prevalence and factors associated with APP are sparse and have yielded inconsistent results. METHODS: We conducted a systematic retrospective audit of the medical records of all admissions in 2010 in the adult wards of a metropolitan public mental health service in Western Australia, having a diagnosis of schizophrenia or schizoaffective disorder. We analysed the rates of APP use, and its association with selected demographic and clinical variables. RESULTS: The prevalence of APP among our sample of 229 patients was high, at 43.2%. APP was associated with a longer hospital stay (p=0.033) and voluntary admission (p=0.027); but APP was not significantly related to: age, gender, diagnosis and treatment by different psychiatrists. CONCLUSIONS: Substantial difference exists between everyday clinical practice and recommendations of practice guidelines of schizophrenia, regarding the use of APP. Prospective studies from different settings exploring the relevant clinical, patient, prescriber and system-related issues are warranted, to comprehend the rationale behind high utilisation of APP in clinical practice.

Does accumulating exposure to illicit drugs bring forward the age at onset in schizophrenia?

OBJECTIVE: Whilst cannabis has been associated with an earlier age at onset in schizophrenia, the impact of amphetamine and/or cocaine plus cannabis consumption on age at onset remains unclear. The present study was designed to test the hypothesis that consumption of amphetamine and/or cocaine in addition to cannabis would lead to an earlier age at onset of schizophrenia than that seen for cannabis consumption alone. A secondary objective was to determine what kind of effect additional substance use exerted (e.g. additive, multiplicative). METHOD: Patients with a diagnosis of schizophrenia were recruited from consecutive admissions to the inpatient and outpatient services of a large psychiatric hospital in Perth, Australia and 167 participants were assessed using the Diagnostic Interview for Psychosis, which included detailed inquiry into illicit drug use in the 12 months prior to the onset of psychiatric symptoms. Participants were categorized into four groups: no illicit substance use (n = 65), cannabis use (n = 68), cannabis plus amphetamine use (n = 25), and cocaine plus cannabis/cocaine plus cannabis plus amphetamine use (n = 9). Analysis of variance was performed to detect trends, and linear regression used to analyze the consumption of each additional substance as a predictor of age at onset. RESULTS: We observed a linear trend for mean age at onset: 23.34 (SD = 6.91) years for no illicit substance use, 22.51 (SD = 5.27) years for cannabis use, 20.84 (SD = 3.48) years for cannabis plus amphetamine use, and 19.56 (SD = 3.54) years for cocaine plus cannabis/cocaine plus cannabis plus amphetamine use; the variation in the means between groups was statistically significant: F(1,163) = 5.66, p = 0.008, Cohen's d = 0.38. For the consumption of each additional substance, age at onset was earlier by 1.2 years: R (2) = 0.034, F(1,165) = 5.72, p = 0.018. CONCLUSIONS: Whilst preliminary, these findings suggest that additional consumption of each substance predicted an earlier age at onset by approximately 1 additional year.

Clusters according to patient need in a long-stay inpatient population with schizophrenia: does executive dysfunction underpin needs-directed care?

PURPOSE: To identify the external validators of patient clusters according to need in a long-stay inpatient population with schizophrenia. METHODS: We recruited without exclusion 112 in-patients with chronic schizophrenia in a long-stay rehabilitation facility of a major psychiatric hospital in Perth, Western Australia. Case managers completed a number of measures for participants, including The Camberwell Assessment of Need-Short Appraisal Schedule, which evaluates health and social needs. Latent class analysis according to patient need was performed to identify clusters within the cohort. One way analysis of variance was used to identify the external validators of these clusters, using variables obtained from the additional study measures (Social Behaviour Schedule, Global Assessment of Function, Basic Everyday Living Skills, Behaviour Rating Inventory of Executive Function-Adult version). RESULTS: Three distinct needs-based clusters with different external profiles were identified. A "low unmet needs" group (n = 50) with relatively intact executive function, with the least problematic behaviour and most independent functioning; a "high unmet need (drug abstinent)" group (n = 43) with greatest executive dysfunction, most problematic behaviour and least independent function; a "high unmet need (drug using)" group (n = 19), with less severe executive dysfunction, and intermediate relative to the other groups on measures of social behaviour and independent functioning. CONCLUSIONS: The clinical heterogeneity we have identified, which may well be explained by executive dysfunction, suggests further exploration of appropriate assessment and streams of care for those in the rehabilitation setting is warranted.

Modification of the Edinburgh Handedness Inventory: a replication study.

The Edinburgh Handedness Inventory was administered to 1224 high school students (605 males and 619 females). Confirmatory factor analysis was used to re-examine its psychometric properties. The results showed that this instrument has poor measurement properties. Removal of a few problematic items improved internal consistency of the questionnaire and improved its validity. The results also suggest that the impact of modification did not affect classification of individuals into left- and right-handedness categories but did influence classification of mixed-handers with the original version classifying significantly more individuals into mixed-handedness category than the modified version.

Social stereotyping of left-handers in Serbia.

Social tolerance towards left-handed people is commonly accepted in the twenty-first century, though not universal. However, at the level of social cognition a subtle bias against this visible minority group might not have disappeared. To investigate this possibility we adopted the theoretical framework of the stereotype content model (SCM) whereby two fundamental dimensions (warmth and competence) are sufficient to explain group differences in stereotype content. We examined how a large sample of medical students (N=300) perceived nine social groups (seven with various physical, social, or mental handicaps, and the two target groups of left- and right-handers), and four "anchor" groups comprising educated people, pensioners, drug addicts, and rich people) which are considered as prototypical in terms of the SCM. Hierarchical cluster analysis was performed to determine similarity of groups in the warmth × competence two-dimensional space. Four clusters were identified, with left- and right-handers located in the same cluster together with educated people. This cluster had higher ratings on both warmth and competence (i.e., more positive stereotype) compared with all other groups. However, within-cluster analysis showed that the left-handed group was perceived as lower on both dimensions compared to the right-handed group. This statistically significant difference suggests that implicit bias against left-handed individuals has not vanished despite pervasive social tolerance. Possible mechanisms that may explain this subtle and subliminal stereotyping are discussed.

Reasons for non-attendance in youth mental health clinics: Insights from mobile messaging communications.

AIM: Non-attendance at appointments in youth mental health services is a common problem which contributes to reduced service effectiveness and unmet needs. Reasons cited by young people for non-attendance are poorly understood. Information derived from short-message-service (SMS) conversations about appointments between patients and clinicians can uncover new insights about the circumstances leading to 'did not attend' events. METHODS: Text messages between young people and clinicians were examined in a retrospective audit of medical records in two youth mental health services in Perth, Australia. Frequently non-attending young people aged 16-24 (n = 40) engaged in 302 SMS message chains about appointments. Mixed methods included quantitative data and qualitative thematic analysis of textual data. RESULTS: Medical reasons (32/190, 16.8%) and forgetfulness (20/190, 10.5%) were the most frequent reasons for non-attendance. Major issues included non-avoidable events while others were potentially preventable and could be addressed by the service. CONCLUSIONS: The analysis of mobile communications in clinical practice can be used for service evaluation and to reveal barriers that impede attendance to ongoing care.

Brief screening for executive dysfunction in schizophrenia in a rehabilitation hospital.

Few tools assessing neurocognitive dysfunction in schizophrenia are able to measure integrated executive functions in the context of the problem-solving demands of a patient's everyday world. The authors evaluated the BRIEF-A (Behavior Rating Inventory of Executive Function-Adult version) Informant Report in 112 inpatients with chronic schizophrenia in a rehabilitation hospital. Factor analysis yielded a three-factor solution (Emotional Regulation, Problem-Solving, Orderliness). The BRIEF-A is psychometrically robust in this population and, in the absence of patient participation, provides an estimate of executive functions in a population that may otherwise be beyond the reach of formal neurocognitive testing.

Impact of the Reelin signaling cascade (ligands-receptors-adaptor complex) on cognition in schizophrenia.

Our previous neurocognitive studies of schizophrenia outlined two clusters of affected subjects--cognitively spared (CS) and cognitive deficit (CD), the latter's characteristics pointing to developmental origins and impaired synaptic plasticity. Here we investigate the contribution of polymorphisms in major regulators of these processes to susceptibility to schizophrenia and to CD in patients. We examine variation in genes encoding proteins at the gateway of Reelin signaling: ligands RELN and APOE, their common receptors APOER2 and VLDLR, and adaptor DAB1. Association analysis with disease outcome and cognitive performance in the Western Australian Family Study of Schizophrenia (WAFSS) was followed by replication analysis in the Australian Schizophrenia Research Bank (ASRB) and in the Health in Men Study (HIMS) of normal aging males. In the WAFSS sample, we observed significant association of APOE, APOER2, VLDLR, and DAB1 SNPs with disease outcome in the case-control and CD-control datasets, and with pre-morbid intelligence and verbal memory in cases. HIMS replication analysis supported rs439401 (APOE regulatory region), and rs2297660 and rs3737983 (APOER2), with an effect on memory performance in normal aging subjects consistent with the findings in schizophrenia cases. APOER2 gene expression analysis revealed lower transcript levels in lymphoblastoid cells from cognitively impaired schizophrenia patients of the alternatively spliced exon 19, mediating Reelin signaling and synaptic plasticity in the adult brain. ASRB replication analysis produced marginally significant results, possibly reflecting a recruitment strategy biased toward CS patients. The data suggest a contribution of neurodevelopmental/synaptic plasticity genes to cognitive impairment in schizophrenia.

Diagnostic criteria for depression in Parkinson's disease: a study of symptom patterns using latent class analysis.

Although major depression is one of the most frequent psychiatric disorders among patients with Parkinson's disease, diagnostic criteria have yet to be validated. The main aim of our study was to validate depressive symptoms using latent class analysis for use as diagnostic criteria for major depression in Parkinson's disease. We examined a consecutive series of 259 patients with Parkinson's disease admitted to 2 movement disorders clinics for regular follow-ups. All patients were assessed with a comprehensive psychiatric interview that included structured assessments for depression, anxiety, and apathy. The main finding was that all 9 Diagnostic and Statistical Manual (4th edition) diagnostic criteria for major depression (ie, depressed mood, diminished interest or pleasure, weight or appetite changes, sleep changes, psychomotor changes, loss of energy, feelings of worthlessness or inappropriate guilt, poor concentration, and suicidal ideation) identified a patient class (severe depression group) with high statistical significance. Latent class analysis also demonstrated a patient class with minimal depressive symptoms (no-depression group), and a third patient class with intermediate depressive symptoms (moderate depression). Anxiety and apathy were both significant comorbid conditions of moderate and severe depression. Taken together, our findings support the use of the full Diagnostic and Statistical Manual (4th edition) criteria for major depression for use in clinical practice and research in Parkinson's disease and suggest that anxiety may be included as an additional diagnostic criterion.