Spontaneous abnormal involuntary movements in first-episode schizophrenia and schizophreniform disorder: baseline rate in a group of patients from an Irish catchment area

Sex difference in the interrelationship between TNF-α and oxidative stress status in first-episode drug-naïve schizophrenia

Background

Increasing evidence indicates that dysregulated TNF-α and oxidative stress (OxS) contribute to the pathophysiology of schizophrenia. Additionally, previous evidence has demonstrated sex differences in many aspects of schizophrenia including clinical characteristics, cytokines, and OxS markers. However, to the best of our knowledge, there is no study investigating sex differences in the association between TNF-α, the OxS system, and their interaction with clinical symptoms in schizophrenia patients, especially in first-episode drug-naïve (FEDN) patients.

Methods

A total of 119 FEDN schizophrenia patients and 135 healthy controls were recruited for this study. Serum TNF-α, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA) were measured. The Positive and Negative Syndrome Scale (PANSS) was applied to evaluate psychotic symptoms. Two-way ANOVA, partial correlation analysis, and multivariate regression analysis were performed.

Results

A sex difference in MDA levels was demonstrated only in healthy controls (F = 7.06, p_Bonferroni = 0.045) and not seen in patients. Furthermore, only male patients had higher MDA levels than male controls (F = 8.19, p_Bonferroni = 0.03). Additionally, sex differences were observed in the association of TNF-α and MDA levels with psychotic symptoms (all p_Bonferroni < 0.05). The interaction of TNF-α and MDA was only associated with general psychopathology symptom in male patients (B = − 0.07, p = 0.02).

Conclusion

Our results demonstrate the sex difference in the relationship between TNF-α, MDA, and their interaction with psychopathological symptoms of patients with schizophrenia.

Using Virtual Reality as a Tool in the Rehabilitation of Movement Abnormalities in Schizophrenia

Movement abnormalities are prevalent across all stages of schizophrenia contributing to poor social functioning and reduced quality of life. To date, treatments are scarce, often involving pharmacological agents, but none have been shown to improve movement abnormalities effectively. Virtual reality (VR) is a tool used to simulate virtual environments where behavioral performance can be quantified safely across different tasks while exerting control over stimulus delivery, feedback and measurement in real time. Sensory information is transmitted via a head mounted display allowing users to directly interact with virtual objects and bodies using gestures and body movements in the real world to perform different actions, permitting a sense of immersion in the simulated virtual environment. Although, VR has been widely used for successful motor rehabilitation in a variety of different neurological domains, none have been exploited for motor rehabilitation in schizophrenia. The objectives of this article are to review movement abnormalities specific to schizophrenia, and how VR can be utilized to restore and improve motor functioning in patients with schizophrenia. Constructing VR-mediated motor-cognitive interventions that can help in retaining and transferring the learned outcomes to real life are also discussed.

Spontaneous and emergent extrapyramidal syndromes in Black Africans with first-episode schizophrenia and first exposure to antipsychotics

BACKGROUND

Persons of African ancestry are thought to carry a higher risk for extrapyramidal syndromes (EPS) in schizophrenia.

AIM

We investigated the phenomenon of spontaneous and treatment-emergent EPS in a sample comprising Xhosa (South Africa) and Yoruba (Nigeria) Africans with first-episode schizophrenia and first exposure to antipsychotics.

METHODS

The Extrapyramidal Symptom Rating Scale (ESRS) and a variety of validated tools were used for the assessment of participants before, and two-weekly after treatment with low dose flupenthixol decanoate. Participants were followed up for 12 months. Association of EPS with clinical characteristics was investigated using Pearson's correlation and linear regression analyses.

RESULTS

Of 88 participants at baseline, 16 (18.1%) had at least one definite EPS prior to antipsychotic exposure and 34 (38.6%) had treatment-emergent EPS. While spontaneous Parkinsonism was associated with negative symptoms (r = 0.2, p = 0.043; β = 0.6, p = 0.043), treatment-emergent EPS demonstrated non-significant correlations with clinical characteristics. Apart from dyskinesia, the frequency of treatment-emergent EPS decreased over 12 months observation.

CONCLUSION

These findings support the hypothesis suggesting that spontaneously occurring Parkinsonism in schizophrenia may be the motor spectrum of negative symptomatology. Future studies of this relationship may lead to early identification of patients who may be more sensitive to EPS.

Tardive Dyskinesia and Dopamine Oxidation, Cumulative Effects

It is likely that tardive dyskinsesia is caused by the oxidation of dopamine in dopaminergic neurons. This oxidation produces oxygen radicals that damage neurons. Damage accumulates until tardive dyskinesia occurs. The use of dopamine D2 receptor inhibitors should be limited to the lowest doses for the shortest duration possible.

First-episode schizophrenia, bipolar disorder and other psychoses in a rural Irish catchment area: Incidence and gender in the Cavan–Monaghan study at 5 years

Background

The potential of first-episode studies in schizophrenia is maximised through systematic epidemiological, clinical and biological comparisons between homogeneous populations of the psychoses.

Aims

To conduct prolonged accrual of ‘all’ cases of non-affective and affective psychotic illness on an epidemiologically complete basis.

Method

Within the region covered by Cavan–Monaghan psychiatric service (population 102 810), all putative cases of first-episode psychosis were diagnosed using DSM–IV.

Results

From 1995 to 2000, 69 cases of psychosis were ascertained, the incidence being 2.3-fold lower in females than in males. On resolving the ‘core’ diagnoses of schizophrenia and bipolar disorder, incidence of schizophrenia among women was 7.5-fold lower than among men whereas incidence of bipolar disorder among women was 6.6-fold lower than among men.

Conclusions

This homogeneous population, which eliminates factors associated with urbanicity and minimises confounding factors such as socioeconomic, ethnic and geographical diversity, shows a markedly reduced incidence among females both of schizophrenia and of bipolar disorder.

Assessment of drug-related movement disorders in schizophrenia

Conventional antipsychotic drugs remain one of the mainstays of treatment of schizophrenia and related psychotic disorders. The therapeutic efficacy of these drugs is well established, both for treatment of acute symptoms and in relapse prevention. Unfortunately, they are associated with a broad range of side-effects, the most prominent of which is the development of a variety of movement disorders (see Box 1). Compared with the conventional antipsychotic agents, the newer, atypical antipsychotics have a lower liability for the acute extrapyramidal side-effects (EPS) and, for a few of the new drugs, there is some evidence of a lower risk of tardive dyskinesia (Barnes & McPhillips, 1999). Nevertheless, even with these newer agents, movement disorders are seen in a significant proportion of patients.

Prevalence of spontaneous dyskinesia in first episode, drug naive schizophrenia, and its relation to the positive and negative symptoms of schizophrenia

Aims and objectives

This study aims to assess the prevalence of abnormal involuntary movement in never medicated patients with schizophrenia and to find its relation with demographic variables, and with the positive and negative symptoms of schizophrenia; this study also aims to assess the topography of the dyskinesia.

Methodology

Socio-demographic data of 100 consecutively selected patients who fulfilled the ICD-10 Diagnostic Criteria for Research were collected in a 12-month period. These patients were rated with the Positive And Negative Syndrome Scale (PANSS) and Abnormal Involuntary Movement Scale (AIMS). Patients were labeled as having spontaneous dyskinesia if they fulfilled the criteria of Schooler and Kane which needs a score of two (mild) in at least two areas or score of three (moderate) or four (severe) in one area.

Results

Fifty two per cent of the study samples were male and 48% were female with mean age of 30.72 years with standard deviation of 8.7 years. Sixteen per cent of the patients had dyskinesia when examined with AIMS. However, only 14% fulfilled the Schooler and Kane's criteria for spontaneous dyskinesia. A strong correlation was found between the presence of dyskinesia and negative symptoms of schizophrenia. 57.1% of these 14 patients had dyskinesia located in their oral and facial region. Seventy one per cent of these patients with dyskinesia had no awareness of their involuntary movements.

Conclusions

Spontaneous dyskinesia, negative symptoms, and lack of awareness of the abnormal involuntary movement can be taken as one of the presenting symptoms of schizophrenia.

Tardive Dyskinesia: A Historical Perspective

The goal of this column is to provide historical context on tardive dyskinesia (TD) to help the reader understand how the concept was studied and evolved over time. Psychiatrists today should understand this history and consider it in combination with more recent data on the neurobiology of TD, including data from animal studies. This combination of classic data with modern science can help readers develop a more complete understanding and lead to a more judicious use of the term TD, after consideration of all of the alternative causes of abnormal movements, including spontaneous dyskinesia (SD). We advocate that clinicians use the term SD when in doubt about the cause of a movement disorder in a given patient, as TD is never distinguishable from SD in a given patient but is instead an issue of a statistical odds ratio.

Postural Stability of Patients with Schizophrenia during Challenging Sensory Conditions: Implication of Sensory Integration for Postural Control

Postural dysfunctions are prevalent in patients with schizophrenia and affect their daily life and ability to work. In addition, sensory functions and sensory integration that are crucial for postural control are also compromised. This study intended to examine how patients with schizophrenia coordinate multiple sensory systems to maintain postural stability in dynamic sensory conditions. Twenty-nine patients with schizophrenia and 32 control subjects were recruited. Postural stability of the participants was examined in six sensory conditions of different level of congruency of multiple sensory information, which was based on combinations of correct, removed, or conflicting sensory inputs from visual, somatosensory, and vestibular systems. The excursion of the center of pressure was measured by posturography. Equilibrium scores were derived to indicate the range of anterior-posterior (AP) postural sway, and sensory ratios were calculated to explore ability to use sensory information to maintain balance. The overall AP postural sway was significantly larger for patients with schizophrenia compared to the controls [patients (69.62±8.99); controls (76.53±7.47); t_1,59 = -3.28, p<0.001]. The results of mixed-model ANOVAs showed a significant interaction between the group and sensory conditions [F_5,295 = 5.55, p<0.001]. Further analysis indicated that AP postural sway was significantly larger for patients compared to the controls in conditions containing unreliable somatosensory information either with visual deprivation or with conflicting visual information. Sensory ratios were not significantly different between groups, although small and non-significant difference in inefficiency to utilize vestibular information was also noted. No significant correlations were found between postural stability and clinical characteristics. To sum up, patients with schizophrenia showed increased postural sway and a higher rate of falls during challenging sensory conditions, which was independent of clinical characteristics. Patients further demonstrated similar pattern and level of utilizing sensory information to maintain balance compared to the controls.

Dysfluent Handwriting in Schizophrenic Outpatients

Taking into account findings in the literature, the author aimed to test whether specific graphical characteristics of handwriting can distinguish patients diagnosed with schizophrenic disorders from healthy controls. Handwriting samples (one sample from each person) from 60 outpatients (29 women, 31 men; age M = 28.5, SD = 5.4) with paranoid schizophrenia were analyzed by three documents examiners and were compared to samples from 60 controls (30 men, 30 women, age M = 28.0, SD = 3.0) without psychiatric disorders. Document examiners assessed 32 graphical features potentially related to schizophrenia. The comparisons between groups revealed that only 7 out of 32 handwriting properties were significantly different in the handwriting of schizophrenic outpatients from controls: the calligraphic forms of letters, loops in ovals, lacking of dots, tremor, sinusoidal baseline, and irregularities size of lower zone. These findings are discussed in terms of motor disturbances in schizophrenia and in relation to the previous research on handwriting of other mental disorders. Similarities between the graphical patterns of handwriting of schizophrenic patients and those of other mental disorders and/or other mental states have been demonstrated.

Determining Whether a Definitive Causal Relationship Exists Between Aripiprazole and Tardive Dyskinesia and/or Dystonia in Patients With Major Depressive Disorder: Part 1

This series of columns has 2 main goals: (1) to explain the use of class warnings by the US Food and Drug Administration and (2) to increase clinicians' awareness of movement disorders that may occur in patients being treated with antipsychotic medications and why it is appropriate and good practice to refrain from immediately assuming the diagnosis is tardive dyskinesia/dystonia (TD). This first column in the series will focus on the second goal, which will then serve as a case example for the first goal. Clinicians should refrain from jumping to a diagnosis of TD because a host of other causes need to be ruled out first before inferring iatrogenic causation. The causal relationship between chronic treatment with dopamine antagonists and TD is based on pharmacoepidemiology (ie, the prevalence of such movement disorders is higher in individuals receiving chronic treatment with such agents than in a control group). There is nothing pathognomonic about movement disorders, nor is there any test that can currently prove a drug caused a movement disorder in a specific individual. Another goal of this series is to describe the types of research that would be needed to establish whether a specific agent has a meaningful risk of causing TD. In this first column of the series, we present the case of a patient who developed orofacial dyskinesia while being treated with aripiprazole. In this case, the movement disorder was prematurely called TD, which led to a malpractice lawsuit. This case highlights a number of key questions clinicians are likely to encounter in day-to-day practice. We then review data concerning the historical background, incidence, prevalence, and risk factors for 2 movement disorders, TD and spontaneous dyskinesia. Subsequent columns in this series will review: (1) unique aspects of the psychopharmacology of aripiprazole, (2) the limited and inconsistent data in the literature concerning the causal relationship between aripiprazole and TD, (3) the use of class warnings by the US Food and Drug Administration, which are automatically applied to a drug if it belongs to a specific therapeutic or pharmacological class unless the manufacturer provides convincing data that it does not warrant such a class label, and (4) the types of prohibitively expensive studies that would be needed to determine whether a meaningful causal relationship between aripiprazole and TD exists.

Abnormal movements in first-episode, nonaffective psychosis: dyskinesias, stereotypies, and catatonic-like signs

Motor abnormalities represent a neurobehavioral domain of signs intrinsic to schizophrenia-spectrum disorders, though they are commonly attributed to medication side effects and remain understudied. Individuals with first-episode psychosis represent an ideal group to study innate movement disorders due to minimal prior antipsychotic exposure. We measured dyskinesias, stereotypies, and catatonic-like signs and examined their associations with: (1) age at onset of psychotic symptoms and duration of untreated psychosis; (2) positive, negative, and disorganized symptoms; (3) neurocognition; and (4) neurological soft signs. Among 47 predominantly African American first-episode psychosis patients in a public-sector hospital, the presence and severity of dyskinesias, stereotypies, and catatonic-like features were assessed using approximately 30-min video recordings. Movement abnormalities were rated utilizing three scales (Dyskinesia Identification System Condensed User Scale, Stereotypy Checklist, and Catatonia Rating Scale). Correlational analyses were conducted. Scores for each of three movement abnormality types were modestly inter-correlated (r=0.29-0.40). Stereotypy score was significantly associated with age at onset of psychotic symptoms (r=0.32) and positive symptom severity scores (r=0.29-0.41). There were no meaningful or consistent associations with negative symptom severity, neurocognition, or neurological soft signs. Abnormal movements appear to represent a relatively distinct phenotypic domain deserving of further research.

Movement disorders in neuroleptic-naïve patients with schizophrenia spectrum disorders

BACKGROUND

Spontaneous Movements Disorders (SMDs) or dyskinetic movements are often seen in patients with schizophrenia and other psychotic disorders, and are widely considered to be adverse consequences of the use of antipsychotic medications. Nevertheless, SMDs are also observed in the pre-neuroleptic ear and among patients who were never exposed to antipsychotic medications. The aim of this study was to determine the extent of SMDs among antipsychotic-naïve patients in a low income setting, and to evaluate contextually relevant risk factors.

METHODS

The study was a cross-sectional facility-based survey conducted at a specialist psychiatric hospital in Addis Ababa, Ethiopia. Consecutive consenting treatment-naïve patients with a diagnosis of schizophrenia, schizoaffective disorder and schizophreniform disorder contacting services for the first time were assessed using the Simpson-Angus Rating Scale (SAS) and the Abnormal Involuntary Movement Scale (AIMS) to evaluate the presence of SMDS. Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS) were administered to evaluate negative and positive symptom profiles respectively. Body mass index (BMI) was used as a proxy measure for nutritional status.

RESULT

Sixty-four patients, 67.2% male (n = 43), with first contact psychosis who met the DSM-IV-TR criteria for schizophrenia (n = 47), schizophreniform disorder (n= 5), and schizoaffective disorder (n = 12) were assessed over a two month study period. Seven patients (10.9%) had SMDs. BMI (OR = 0.6, 95% CI = 0.40, 0.89; p = 0.011) and increasing age (OR = 1.10; 95% CI = 1.02, 1.20; p = 0.017) were associated with SMD.

CONCLUSIONS

This finding supports previous suggestions that abnormal involuntary movements in schizophrenia and other psychotic disorders may be related to the pathophysiology of psychotic disorders and therefore cannot be attributed entirely to the adverse effects of neuroleptic medication.

Electromyographic analysis of masseter and temporal muscles, bite force, masticatory efficiency in medicated individuals with schizophrenia and mood disorders compared with healthy controls

This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.

Tardive and spontaneous dyskinesia incidence in the general population

BACKGROUND

To identify the incidence rate of spontaneous dyskinesia (SD) and tardive dyskinesia (TD) in a general population and to examine the association between dykinesia and potential risk factors (exposure to metoclopramide [MCP], antipsychotic drugs, and history of diabetes and psychoses).

METHODS

A retrospective cohort study was conducted for the years 2001 through 2010, based on medical claims data from the Deseret Mutual Benefit Administrators (DMBA).

RESULTS

Thirty-four cases of TD and 229 cases of SD were identified. The incidence rate of TD among persons previously prescribed an antipsychotic or metoclopramide (MCP) (per 1,000) was 4.6 (1.6-7.7) for those with antipsychotic drug use only, 8.5 (4.8-12.2) for those with MCP use only, and 15.0 (2.0-28.1) for those with both antipsychotic and MCP use. In the general population, the incidence rate (per 100,000 person-years) of TD was 4.3 and of probable SD was 28.7. The incidence rates of TD and SD increased with age and were greater for females. Those with diabetes or psychoses had almost a 3-fold greater risk of TD than those without either of these diseases. Persons with schizophrenia had 31.2 times increased risk of TD than those without the disease. Positive associations also existed between the selected diseases and the incidence rate of probable SD, with persons with schizophrenia having 4.4 times greater risk of SD than those without the disease.

CONCLUSIONS

SD and TD are rare in this general population. Diabetes, psychoses, and especially schizophrenia are positively associated with SD and TD. A higher proportion of those with SD present with spasm of the eyelid muscles (blepharospasm) compared more with the TD cases who present more with orofacial muscular problems.

Prospective relationship of duration of untreated psychosis to psychopathology and functional outcome over 12 years

BACKGROUND

The duration of untreated psychosis is well recognised as an independent predictor of symptomatic and functional outcome in the short term and has facilitated the development of worldwide early intervention programmes. However, the extent and mechanisms by which it might influence prognosis beyond a decade remain poorly understood.

METHODS

The authors examined the relationship between duration of untreated psychosis and outcome 12years after a first episode of psychosis and assessed whether its relationship with function is affected by symptoms in a prospective, 12-year follow-up of an epidemiologically-based inception cohort.

RESULTS

Longer duration of untreated psychosis predicted poorer remission status, more severe positive and negative symptoms, and greater impairment in general functioning, social functioning and quality of life at 12years on standardised measures, independent of other factors at baseline. It was not associated with gainful employment, for which education was the only predictor, or independent living, for which age was the only predictor. The relationship between duration of untreated psychosis and functional outcome was mediated by concurrent psychopathology, particularly negative symptoms.

CONCLUSIONS

These results provide qualified support for the potential long-term benefit of reduction in the duration of untreated psychosis in terms of improvement in symptoms and functional outcome. Its failure to predict real-life outcomes such as independent living and gainful employment could reflect the importance of pre-existing socio-cultural factors such as individual opportunity. The relationship between duration of untreated psychosis and negative symptoms was largely responsible for its effect on function, suggesting a possible long-term protective mechanism against disability.

Dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia, first-degree relatives and healthy controls: a meta-analysis

BACKGROUND

Several studies have reported the presence of dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia as well as in their first-degree relatives. These movement disorders may therefore form an integral part of the illness and its (genetic) liability.

METHOD

A systematic search was conducted in the Medline, EMBASE, and PsychINFO databases to identify studies reporting on dyskinesia and parkinsonism assessed in antipsychotic-naive patients with schizophrenia (n = 213) and controls (n = 242) and separately in nonill first-degree relatives (n = 395) and controls (n = 379). Effect sizes were pooled using random-effect models to calculate odds ratios (ORs) to compare the risk of these movement disorders among patients and healthy relatives each with matched controls.

RESULTS

Antipsychotic-naive schizophrenia was found to be strongly associated with dyskinesia (OR: 3.59, 95% confidence interval [CI]: 1.53-8.41) and parkinsonism (OR: 5.32, 95% CI: 1.75-16.23) compared with controls. Dyskinesia and parkinsonism were also significantly more prevalent in healthy first-degree relatives of patients with schizophrenia as compared with healthy controls (OR: 1.38, 95% CI: 1.06-1.81, and OR: 1.37, 95% CI: 1.05-1.79, respectively).

CONCLUSION

The results suggest that movement disorders, and by inference abnormalities in the nigrostriatal pathway, are not only associated with schizophrenia itself but may also be related to the (genetic) risk of developing the disease.

Gray and white matter volumetric and diffusion tensor imaging (DTI) analyses in the early stage of first-episode schizophrenia

PURPOSE

To determine whether statistical analyses of quantitative MR imaging data, including morphological changes, mean diffusivity (MD), and fractional anisotropy (FA), could provide useful biomarkers in early stage of first-episode schizophrenia.

MATERIALS AND METHODS

Twenty-three patients, who met all the criteria in the DSM-IV-TR category for schizophrenia excluding the duration of the disease (less than 6 months of follow-up), were examined by MR imaging during the initial consultation. Nineteen of the 23 patients were finally diagnosed to have schizophrenia after a 6-month follow-up, and they were included in this study as having been in the early stage of first-episode schizophrenia. Nineteen healthy volunteers also underwent MR imaging as age-matched controls. Three-dimensional spoiled gradient recalled acquisition with steady state (3D-SPGR) and diffusion tensor imaging (DTI) were performed at 3T. Image processing for voxel-based morphometry, a fully automatic technique for a computational analysis of differences in regional brain volume throughout the entire brain, was conducted using the Statistical Parametric Mapping 5 software package (SPM5). The 3D-SPGR images in the native space were bias-corrected; spatially normalized; segmented into gray matter, white matter, and cerebrospinal fluid images; and intensity-modulated using SPM5. A voxel-based analysis was conducted using both the MD and FA maps computed from DTI. The customized MD and FA template specific to this study was created from all participants. Thereafter, all the MD and FA maps in the native space were transformed onto the stereotactic space by registering each of the images to the customized MD and FA template. The two groups were compared using SPM5. Age and sex were treated as confounding covariates.

RESULTS

The patients demonstrated a significant increase in the MD of the left parahippocampal gyrus, left insula, and right anterior cingulate gyrus in comparison to the control subjects (FDR corrected p<0.05). No significant difference was observed in the correlation between the gray/white matter volume and FA.

CONCLUSION

These findings suggest that structural abnormalities in the brain are present during the early stage of first-episode schizophrenia and MD might therefore be a sensitive marker for the detection of these abnormalities.

Neurological disorders in schizophrenia

Schizophrenia (SZ) is a complex, heterogeneous, and disabling psychiatric disorder that impairs multiple aspects of human cognitive, perceptual, emotional, and behavioral functioning. SZ is relatively frequent (prevalence around 1%), with onset usually during adolescence or early adulthood, and has a deteriorating course. The rapidly growing area of neuroimaging research has has found clear evidence of many cortical and subcortical abnormalities in individuals with SZ. In this article the most recent findings from multiple studies on neurological disorders in SZ are reviewed, and the authors make a strong argument for a neurological basis of the schizophrenic process.

Spontaneous movement disorders in antipsychotic-naive patients with first-episode psychoses: a systematic review

BACKGROUND

Spontaneous movement disorders (SMDs), such as spontaneous dyskinesia and parkinsonism, have been described in patients with schizophrenia who have never been treated with antipsychotic medication. Their presence has been documented extensively in chronic schizophrenia but not at the time of illness onset.

METHOD

We performed a systematic review of studies investigating spontaneous abnormal movements elicited on clinical examination in antipsychotic-naive patients with first-episode psychosis.

RESULTS

We identified a total of 13 studies. Findings suggest a spontaneous dyskinesia median rate of 9% and a spontaneous parkinsonism median rate of 17%. Information on akathisia and dystonia was limited. The presence of SMDs may be associated with negative symptoms and cognitive dysfunction.

CONCLUSIONS

These findings support the notion that spontaneous abnormal movements are part of a neurodysfunction intrinsic to the pathogenesis of schizophrenia. Future studies should further investigate the role of basal ganglia and extrapyramidal pathways in the pathophysiology of psychosis, with particular attention to treatment implications.

Neurological signs and involuntary movements in schizophrenia: intrinsic to and informative on systems pathobiology

While it has long been considered whether the pathobiology of schizophrenia extends beyond its defining symptoms to involve diverse domains of abnormality, in the manner of a systemic disease, studies of neuromotor dysfunction have been confounded by treatment with antipsychotic drugs. This challenge has been illuminated by a new generation of studies on first-episode schizophrenia before initiation of antipsychotic treatment and by opportunities in developing countries to study chronically ill patients who have remained antipsychotic naive due to limitations in provision of psychiatric care. Building from studies in antipsychotic-naive patients, this article reviews 2 domains of neuromotor dysfunction in schizophrenia: neurological signs and involuntary movements. The presence and characteristics of neurological signs in untreated vis-à-vis treated psychosis indicate a vulnerability marker for schizophrenia and implicate disruption to neuronal circuits linking the basal ganglia, cerebral cortex, and cerebellum. The presence and characteristics of involuntary movements in untreated vis-à-vis treated psychosis indicate an intrinsic feature of the disease process and implicate dysfunction in cortical-basal ganglia-cortical circuitry. These neuromotor disorders of schizophrenia join other markers of subtle but pervasive cerebral and extracerebral, systemic dysfunction, and complement current concepts of schizophrenia as a disorder of developmentally determined cortical-basal ganglia-thalamo-cortical/cerebellar network disconnectivity.

Spontaneous dyskinesia in first-episode psychosis in a Southeast Asian population

Spontaneous dyskinesia in first-episode psychosis was described previously with varying incidence rates ranging from zero to 53%. Dyskinesia was also found to be more common in siblings of patients with both schizophrenia and dyskinesia. This condition was linked with structural brain abnormalities and posited to be another subtype of schizophrenia with striatal pathology. Whether there are ethnic variations in the rates of spontaneous dyskinesia is unknown because of the paucity of studies in this area. This study aims to establish the rates of spontaneous dyskinesia in a Southeast Asian population of drug-naive patients experiencing their first psychotic episode and to examine the clinical correlates. A total of 908 patients were examined, of which, 76.1% were Chinese; 15.4%, Malays; 6.2%, Indians; and 2.3%, from other minor ethnic groups. Schizophrenia was diagnosed in 48.9% of the population. There were 3 patients of Chinese descent who had "minimal" or "mild" dyskinetic movements when rated with the Abnormal Involuntary Movement Scale, but none fulfilled the Schooler and Kane criteria for spontaneous dyskinesia. Their dyskinetic movements resolved when reassessed 3 and 6 months after treatment with antipsychotic medications. Of the 3 patients, 2 were treatment resistant and subsequently treated with clozapine. This is the largest study to date examining the prevalence of spontaneous dyskinesia. We hypothesize that there is an ethnically based difference in the rates of spontaneous dyskinesia that could reflect underlying genetic variations. Patients with dyskinetic movements at baseline could have a more treatment refractory course of illness.

Relations between movement disorders and psychopathology under predominantly atypical antipsychotic treatment in adolescent patients with schizophrenia

OBJECTIVE

To examine relations between movement disorders (MD) and psychopathological symptoms in an adolescent population with schizophrenia under treatment with predominantly atypical antipsychotics.

METHOD

MD symptoms and psychopathology were cross-sectionally assessed in 93 patients (aged 19.6 +/- 2.2 years) using Tardive Dyskinesia Rating Scale (TDRS), Abnormal Involuntary Movement Scale (AIMS), Extrapyramidal Symptom Scale (EPS), Barnes Akathisia Scale (BAS), Brief Psychiatric Rating Scale (BPRS) and the Schedule for Assessment of Negative/Positive Symptoms (SANS/SAPS).

RESULTS

All patients with MD symptoms (n = 37; 39.8 %) showed pronounced global psychpathological signs (SANS/SAPS, BPRS: p = 0.026, p = 0.033, p = 0.001) with predominant anergia symptoms (p = 0.005) and inclinations toward higher anxiety- and depression-related symptoms (p = 0.051) as well as increased thought disturbance (p = 0.066). Both negative symptoms and anergia showed trends for positive correlations with tardive dyskinesia (p = 0.068; p = 0.065) as well as significant correlations with parkinsonism symptoms (p = 0.036; p = 0.023). Akathisia symptoms correlated significantly with hostile and suspicious symptoms (p = 0.013). A superfactor-analysis revealed four factors supporting the aforementioned results.

CONCLUSION

MD symptoms and psychopathology are in some respects related to each other. Motor symptoms representing on the one hand trait characteristics of schizophrenia might additionally be triggered by antipsychotics and finally co-occur with more residual symptoms within a long-term treatment.

The evaluation and management of patients with first-episode schizophrenia: a selective, clinical review of diagnosis, treatment, and prognosis

Patients who present with a first episode of psychosis pose many challenges to psychiatry. While some morbidity from schizophrenia is probably not modifiable once acute psychosis has occurred, the best management of this stage of illness nevertheless holds the promise of improving long-term outcomes. We review the clinical literature on first-episode psychosis to derive clinical guidance with regard to timely diagnosis and optimal pharmacological and nonpharmacological treatment. We describe the illness course and the prognosis for this acute phase of illness and the immediate, postpsychotic period.

Fronto-cerebellar systems are associated with infant motor and adult executive functions in healthy adults but not in schizophrenia

Delineating longitudinal relationships between early developmental markers, adult cognitive function, and adult brain structure could clarify the pathogenesis of neurodevelopmental disorders such as schizophrenia. We aimed to identify brain structural correlates of infant motor development (IMD) and adult executive function in nonpsychotic adults and to test for abnormal associations between these measures in people with schizophrenia. Representative samples of nonpsychotic adults (n = 93) and people with schizophrenia (n = 49) were drawn from the Northern Finland 1966 general population birth cohort. IMD was prospectively assessed at age 1 year; executive function testing and MRI were completed at age 33-35 years. We found that earlier motor development in infancy was correlated with superior executive function in nonpsychotic subjects. Earlier motor development was also normally associated with increased gray matter density in adult premotor cortex, striatum, and cerebellum and increased white matter density in frontal and parietal lobes. Adult executive function was normally associated with increased gray matter density in a fronto-cerebellar system that partially overlapped, but was not identical to, the gray matter regions normally associated with IMD. People with schizophrenia had relatively delayed IMD and impaired adult executive function in adulthood. Furthermore, they demonstrated no normative associations between fronto-cerebellar structure, IMD, or executive function. We conclude that frontal cortico-cerebellar systems correlated with adult executive function are anatomically related to systems associated with normal infant motor development. Disruption of this anatomical system may underlie both the early developmental and adult cognitive abnormalities in schizophrenia.

Prevalence of movement disorders in adolescent patients with schizophrenia and in relationship to predominantly atypical antipsychotic treatment

OBJECTIVE

To examine prevalence of movement disorders (MDs) such as tardive dyskinesia (TD), parkinsonism or akathisia in an adolescent population with schizophrenia and in relationship to predominantly atypical antipsychotic treatment.

METHOD

Ninety-three patients (aged 19.6+/-2.2 years) were ascertained in this cross-sectional/retrospective study. 76 patients (81.7%) received atypical, 10 (10.8%) typical antipsychotics and 7 (7.5%) combinations of atypical/typical antipsychotics. MD symptoms were assessed using Tardive Dyskinesia Rating Scale (TDRS), Abnormal Involuntary Movement Scale (AIMS), Extrapyramidal Symptom Scale (EPS), Barnes Akathisia Scale (BAS).

RESULTS

Movement disorder symptoms were found in 37 patients (39.8%) fulfilling strict/subthreshold criteria for TD (5.4/11.8%), parkinsonism (2.2/25.8%) or akathisia (1.1/11.8%), respectively. Patients treated with typical antipsychotics displayed a significantly higher EPS-score (P=0.036) and a tendency towards a higher BAS-score (P=0.061) compared to patients with atypical antipsychotics. Treatment durations with typical/atypical antipsychotics showed trends towards advantages of atypical antipsychotics with regard to parkinsonism/akathisia symptoms (P=0.061; P=0.054), but not with regard to TD symptoms (P=0.003), possibly due to confounding effects.

CONCLUSION

Under treatment with atypical antipsychotics MD symptoms are less prevalent and less pronounced than under typical antipsychotics. We speculate that the finding of relatively high prevalence rates of subthreshold MD symptoms may be, at least partially, explained by previous or combined therapy with typical antipsychotics.

Spontaneous dyskinesia and familial liability to schizophrenia

Several factors suggest that spontaneous dyskinesia may be a useful supplemental phenotype for further elucidating the specific nature of the genetic contribution to schizophrenia. For example, involuntary movement abnormalities have been observed in both medicated and unmedicated schizophrenia patients, in individuals with schizotypal personality disorder, and sometimes in siblings of schizophrenia patients. However, there are many inconsistencies present in the literature to date. The current study thus sought to investigate the existence of spontaneous dyskinesia in schizophrenia patient probands, their non-psychotic siblings, and healthy controls in order to clarify its potential value as an "endophenotype" in genetic studies of schizophrenia. Videotaped interviews were coded for the presence of spontaneous, involuntary movement abnormalities by a trained and reliable rater using computer assisted technology who was blind to group and family status. The results of this study indicated that siblings of schizophrenia patients did not display significantly more involuntary movements compared to controls, although tremor was observed in a few siblings. In contrast, schizophrenia patients did display significantly more involuntary movements compared to controls as well as their non-psychotic siblings. The lack of significant differences between siblings and controls argues against a strong association between spontaneous dyskinesia and an "unexpressed" genetic liability to schizophrenia. Thus, it appears that involuntary movement abnormalities may be limited in their utility as endophenotypes in genetic studies of schizophrenia, despite being associated with, and perhaps predictive of, schizophrenia itself.

Relationship of neuromotor disturbances to psychosis symptoms in first-episode neuroleptic-naive schizophrenia patients

From the very inception of the modern diagnostic scheme for psychotic disorders, abnormalities in motor function have been observed in these conditions. Despite convergence from multiple areas of research supporting the notion that multiple frontal-subcortical circuits regulate motor and limbic behavior, the precise relationship between motor abnormalities and psychopathology has not been elucidated. The goals of this study were to examine the prevalence of extrapyramidal signs (EPS) in first-episode schizophrenia patients and their relationships to three psychopathological dimensions (positive psychosis syndrome, negative syndrome, and disorganization). We assessed EPS using traditional observer-based as well as quantitative instrumental measures in 39 neuroleptic-naive first-episode schizophrenia subjects. Subjects were followed for 6 months after initiating antipsychotic treatment to examine the stability of motor-limbic relationships. Four main findings emerged from this study. First, depending on the measure used the prevalence of dyskinesia prior to treatment ranged from 13% to 20%. The prevalence of parkinsonism ranged from 18% to 28%. Second, severity of dyskinesia was associated with the positive psychotic syndrome; whereas parkinsonism was associated with the positive psychosis, negative syndrome and disorganization. Third, psychopathology improved significantly across all symptom dimensions following antipsychotic treatment, while EPS remained stable. This suggests that some motor abnormalities in schizophrenia may reflect trait characteristics. Fourth, abnormalities on the pre-treatment instrumental measure of parkinsonism predicted greater improvement on positive psychosis symptoms following treatment (p=0.008). Our findings support the notion that neuromotor disturbances may be a core feature of schizophrenia in a substantial proportion of patients and implicate multiple fronto-striatal circuits regulating limbic and neuromotor behavior in schizophrenia.

Extrapyramidal symptoms in unmedicated schizophrenia

Studies of spontaneous extrapyramidal symptoms, dyskinesia and parkinsonism, in unmedicated schizophrenia are of importance in understanding their underlying pathology and relation to the psychosis. This is a study of extrapyramidal symptoms using Abnormal Involuntary Movements Scale for dyskinesia and Simpson-Angus Scale for parkinsonism in 143 schizophrenia patients who never received antipsychotic medication. Psychopathology was measured using the Positive and Negative Syndrome Scale. Dyskinesia was present in 35% of patients and parkinsonism in 15%. The two disorders coexisted in 11 subjects. Orofacial dyskinesia, rigidity and tremor were common symptoms noted. There was no significant change in the rates and total scores of dyskinesia and parkinsonism with gender, age, duration of illness or age at onset of psychosis. Dyskinesia was unrelated to psychopathology. Parkinsonism score correlated positively with the motor symptom cluster of psychopathology. Dyskinesia and parkinsonism scores correlated positively with each other and parkinsonism score discriminated presence of dyskinesia. The associations between the spontaneous abnormal movements and other aspects of schizophrenia differed from those described in treated patients. Dyskinesia and parkinsonism are an integral part of the schizophrenia disease process whose relationship with other factors could be influenced by antipsychotic drug treatment.

Extrapyramidal symptoms and signs in first-episode, antipsychotic exposed and non-exposed patients with schizophrenia or related psychotic illness

Movement disorders in first-episode psychosis are increasingly recognized; however, the prevalence and clinical correlates are uncertain. We compared antipsychotic exposed (< 12 weeks) with nonexposed first-episode patients, and report prevalence as well as clinical and demographic variables associated with extrapyramidal dysfunction. Data are baseline assessments from a multicentre, international drug trial of first-episode psychosis (n = 535). Analysis included the Extrapyramidal Symptom Rating Scale, Premorbid Adjustment Scale, and the Positive and Negative Syndrome Scale. Of non-exposed patients, 28.1% (n = 47/167) had at least one mild sign of extrapyramidal dysfunction, as did 46.3% (n = 169/365) of previously exposed patients. Hypokinetic Parkinsonism was the most prevalent disorder. The severity of movement disorders and negative symptoms were correlated; however, the effect sizes were small. Logistic regression analysis indicated that the salient risk factors for all patients were: previous antipsychotic exposure [odds ratio (OR) = 2.4; 95% confidence interval (CI) 1.6-3.6] and poor premorbid functioning (OR = 1.8; 95% CI 1.2-2.6). For the non-exposed group (n = 167), the significant risk factors were: having severe mental illness in the family (OR = 2.9; 95% CI 1.2-7.2) and poor premorbid functioning (OR = 2.3; 95% CI 1.0-5.3). For the previously exposed group (n = 368), the significant variables were: poor premorbid functioning (OR = 1.8; 95%CI 1.2-2.8) and shorter duration of untreated psychosis (OR = 0.78; 95% CI 0.64-0.94). Although antipsychotic exposure was associated with extrapyramidal signs, the results indicate that many first-episode patients with no exposure to antipsychotics also had extrapyramidal dysfunction. In this group, family history and poor premorbid functioning appear to be associated with increased risk for movement disorders.

Clinical rating scales and instruments: how do they compare in assessing abnormal, involuntary movements?

OBJECTIVE

Recent studies have shown that quantitative instrumental measurements are more sensitive than clinical rating scales to subclinical dyskinesia and parkinsonism. We therefore hypothesized that an instrumental assessment would be more sensitive to the presence of dyskinetic and parkinsonian movements than the Abnormal Involuntary Movement Scale (AIMS), the Dyskinesia Identification Scale, Condensed User Version (DISCUS), and the Simpson-Angus Scale (SAS). We also hypothesized that the DISCUS, by virtue of its more detailed protocol, would be more sensitive than the AIMS.

METHOD

Using blinded raters, we compared the clinical rating scales with instrumental measurements in 100 patients referred to a movement disorders clinic. We collected demographic data, risk factors for tardive dyskinesia, current medication use, Axis I and III disorders, and an estimate of cognitive functioning using the Mini-Mental Status Examination.

RESULTS

There was no significant difference between the AIM and the DISCUS in the identification of dyskinesia. However, an instrumental assessment revealed a significantly greater prevalence of dyskinesia. The Mini-Mental Status Examination was the most prominent predictor of both instrumental and clinical measurements of parkinsonian and dyskinetic movements.

CONCLUSIONS

It appears that even trained raters, utilizing standard rating scales, may underestimate the prevalence of some motor abnormalities. Instrumental ratings may be helpful to both the clinician and investigator, particularly when abnormal movements are not clinically obvious. The relationship between cognitive impairment and motor abnormalities remains an important area for further research.

Assessing and monitoring antipsychotic-induced movement disorders in hospitalized patients: a cautionary study

OBJECTIVE

To assess the amount of documentation and level of assessment provided by attending physicians and nursing staff in regard to extrapyramidal symptoms (EPS) experienced by hospitalized patients with varied DSM-IV diagnoses regularly treated with antipsychotic medication.

METHOD

We examined the medical records of 204 hospitalized patients. All medical records were examined retrospectively from consecutive admissions beginning in January 1996. We identified demographics, length of hospitalization, diagnosis, and antipsychotic and adjunct medication. EPS were classified into dystonia, parkinsonism, akathisia, and tardive dyskinesia (TD). For each type of EPS, 2 independent raters rated the quality of assessment based on dimensions of severity, location, and laterality.

RESULTS

The extent of interrater agreement was found to be 91.1%. Parkinsonism and akathisia were more frequently assessed, compared with TD and dystonia. However, the medical records examined showed generally poor assessment and documentation of EPS. The percentage of medical records with "no description" for each EPS classification was as follows: dystonia (89%), parkinsonism (71%), akathisia (67%), and TD (94%).

CONCLUSIONS

The major finding of this study was a high rate of failure to document the assessment and course of EPS. This finding suggests that clinicians do not recognize the importance of documenting these significant adverse events. This shortcoming can be corrected with increased awareness of EPS and increased training in their physical examination.

Neural damage in the lenticular nucleus linked with tardive dyskinesia in schizophrenia: a preliminary study using proton magnetic resonance spectroscopy

We investigated, using proton magnetic resonance spectroscopy (1H-MRS), whether the tardive dyskinesia (TD) often seen in schizophrenic patients is associated with cellular abnormalities in the basal ganglia system. The subjects in this study included schizophrenic patients with TD (TD group, n=7), schizophrenic patients without TD (non-TD group, n=7), and healthy volunteers (N group, n=7). We examined the 1H-MRS peaks of N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) in the regions of the left and right lenticular nucleus. In the left lenticular nucleus, the Cho/Cr ratio was significantly greater in the TD and non-TD groups than in the N group (Mann-Whitney U test; p<0.007 and p<0.006, respectively). Further, a significant linear trend was observed in the means of the ratio across the three groups (p<0.005); the TD group was the highest, the N group the lowest, and the non-TD group intermediate. No significant difference in the NAA/Cr ratio was found among groups. These results indicate that neural abnormalities in the basal ganglia may be linked with the neuroleptic medications and the process of the fundamental illness per se, and that more excessive damage to this neural substrate may lead to development of TD. However, as this is a preliminary study, further studies with a large number of subjects are required to verify our findings.

Vulnerability to involuntary movements over a lifetime trajectory of schizophrenia approaches 100%, in association with executive (frontal) dysfunction

This study assessed the prevalence of involuntary movements among older inpatients with severe schizophrenia, many of whom had experienced a lifetime of illness and its treatment, and examined their neuropsychological correlates. The subjects of this study were 128 inpatients with a DSM-IV diagnosis of schizophrenia. They were assessed using the Abnormal Involuntary Movement Scale, the Mini-Mental State Examination for general cognitive impairment and the Executive Interview for executive dyscontrol; additionally, their medical records were reviewed in detail for treatment histories. Prevalence of involuntary movements was examined and their clinical correlates determined in relation to topography of movement disorder using logistic regression. In schizophrenia, prevalence of involuntary movements was: age <65years, 63%; 65-75years, 80%; >75years, 93%. The primary correlate both of overall and of orofacial movements was poor executive function, whereas the primary correlate of limb-trunkal movements was poor general cognitive function. On approaching the limits of human longevity following a lifetime trajectory of illness and its treatment, essentially 'all' patients with schizophrenia appear inherently vulnerable to the emergence of involuntary movements in topographically specific association with cognitive deficits.

Awareness of tardive dyskinesia in Asian patients with schizophrenia

While ethnocultural differences in risk of tardive dyskinesia (TD) have been suggested, no previous studies have examined whether this factor also plays a role in lack of awareness of TD. This study examined this question in an Asian population with schizophrenia. Six hundred seven patients in a state mental hospital in Singapore were assessed using the Abnormal Involuntary Movement Scale (AIMS) and the Simpson-Angus Rating Scale. Of the 607 patients, 242 (39.9%) met criteria for TD, and 163 (67.4%) patients were not aware of the presence of TD. No significant differences in terms of age, gender, and duration of illness were found between those aware of their TD and those not aware. Daily neuroleptic doses and scores for the AIMS and Simpson-Angus Rating Scale were significantly different, although after logistic regression, only the Simpson-Angus Rating Scale scores remained significant. The finding that a large proportion of our patients lacked awareness of their TD is consistent with other reports in the West and provides evidence that this feature is characteristic of the illness rather than of a specific ethnocultural group. We found an association between lack of awareness and greater severity of extrapyramidal symptoms (EPS), suggesting that there may be a subtype of TD in which lack of awareness and greater vulnerability of developing EPS are features.

The current status of tardive dyskinesia

OBJECTIVE

This paper aims to provide an overview of the current knowledge on neuroleptic-induced tardive dyskinesia (TD) in relation to its clinical features, risk factors, pathophysiology and management.

METHOD

The published literature was selectively reviewed and assessed.

RESULTS

Tardive diskinesia is a common neurological side-effect of neuroleptic medication, the cumulative incidence of which increases with increasing duration of treatment. Its clinical manifestations are diverse and subsyndromes have been described. Many risk factors for TD are now recognised, but increasing age remains pre-eminent as a risk factor. The pathophysiology of TD is not completely understood. Of the neurotransmitter hypotheses, the dopamine receptor supersensitivity hypothesis and the gamma-aminobutyric acid insufficiency hypothesis are the main contenders. There is increasing recognition that TD may in fact be caused by neuroleptic-induced neuronal toxicity through free radical and excitotoxic mechanisms. The occurrence of spontaneous dyskinesias in schizophrenic patients and even healthy subjects suggests that neuroleptics act on a substratum of vulnerability to dyskinesia. As no effective treatment for TD is available, the primary emphasis is on prevention. Many drugs can be tried to reduce symptoms in established cases. The increasing use of atypical neuroleptics has raised the possibility of a lower incidence of TD in the future.

CONCLUSIONS

After four decades of clinical recognition, the pathophysiology of TD is still not understood and no effective treatment is available. Its prevention with the optimal usage of currently available drugs and regular monitoring of patients on long-term neuroleptic treatment remain the best strategies to reduce its impact.

Dopamine D2 receptor occupancy by olanzapine or risperidone in young patients with schizophrenia

A crucial characteristic of antipsychotic medication is the occupancy of the dopamine (DA) D2 receptor. We assessed striatal DA D2 receptor occupancy by olanzapine and risperidone in 36 young patients [31 males, 5 females; mean age 21.1 years (16-28)] with first episode schizophrenia, using [123I]iodobenzamide (IBZM) SPECT. The occupancy of DA D2 receptors was not significantly different between olanzapine and risperidone. However, in subgroups of most prescribed doses, DA D2 occupancy was higher in the risperidone 4-mg group (79%) compared to the olanzapine 15-mg group (62%). [123I]IBZM binding ratios decreased with olanzapine dose (r = -0.551; P < 0.01), indicating higher DA D2 receptor occupancy with higher olanzapine dose. Akathisia and positive symptoms were correlated with [123I]IBZM binding ratio (r = -0.442; P < 0.01; and r = -0.360; P < 0.05, respectively). Prolactin (PRL) levels were elevated in the risperidone, but not in the olanzapine group, at comparable D2 receptor occupancy levels. In the olanzapine group, PRL levels were correlated with [123I]IBZM binding ratio (r = -0.551; P < 0.01). In conclusion, both olanzapine and risperidone induce a high striatal D2 receptor occupancy, dependent on dose and group formation. The lower incidence of prolactin elevation with olanzapine, compared to risperidone, may not be attributed to a lower D2 receptor occupancy.

Precursors to schizophrenia: do biological markers have specificity?

This review addresses childhood antecedents and biological markers of schizophrenia within a neurodevelopmental framework. General-population birth-cohort studies illustrate delays in developmental milestones, abnormalities in social functioning, and cognitive deficits throughout childhood, adolescence, and early adulthood. Abnormal neurology and motor dysfunction have been measured in children prior to the onset of schizophrenia, at first onset of disease, and in those with chronic schizophrenia. Minor physical anomalies, a static marker of developmental disturbance, are also increased in schizophrenia. None of these factors has high specificity for this disorder. This review examines the associations between these precursors and some etiological factors for schizophrenia, comments on their lack of complete specificity to this psychotic syndrome, and considers their usefulness as predictors of risk.