Plasma homovanillic acid levels in first-episode schizophrenia. Psychopathology and treatment response.

OBJECTIVES: To examine plasma homovanillic acid (pHVA) levels in first-episode schizophrenia, to compare pHVA levels in patients and controls, and to assess the association of pHVA levels with psychopathology and treatment response. METHODS: Forty-one patients entered the study, and pHVA levels were measured at baseline and on a weekly basis for up to 6 weeks of open standardized neuroleptic treatment. Psychopathology was evaluated with the Schedule for Affective Disorders and Schizophrenia, the Scale for Assessment of Negative Symptoms, and the Clinical Global Impressions scale. Ten healthy controls were used for comparison of baseline pHVA levels. RESULTS: No differences were observed between patients and controls. Baseline pHVA level was not associated with psychopathology but was associated with time to reach remission. Baseline pHVA levels and week-1 pHVA levels were higher in responders than nonresponders. Regardless of responsiveness, female participants had higher pHVA levels than male participants throughout the study. The pattern of pHVA levels with treatment was similar in all patients with a short-term rise initially and then a decrease toward baseline values. CONCLUSIONS: These findings suggest that pHVA levels have prognostic significance for response and time to reach remission. Qualitative and quantitative differences between first-episode patients' pHVA levels and studies using a long-term, neuroleptic-exposed population suggest that changes occur with neuroleptic treatment or the progression of the illness.

Incidence and correlates of tardive dyskinesia in first episode of schizophrenia.

BACKGROUND: There is controversy over whether tardive dyskinesia (TD) is solely a consequence of antipsychotic drug treatment or in part may reflect an intrinsic aspect of the disease process. Pathophysiologic factors could, independently or in concert with drug effects, lead to the development of dyskinetic signs. METHODS: We studied prospectively 118 patients in their first episode of psychosis who were treatment-naive or had less than 12 weeks of antipsychotic drug exposure at study entry. Patients received standardized antipsychotic drug treatment and were evaluated for up to 8 1/2 years with regular assessments of psychopathologic signs and symptoms and side effects. RESULTS: The cumulative incidence of presumptive TD was 6.3% after 1 year of follow-up, 11.5% after 2 years, 13.7% after 3 years, and 17.5% after 4 years. Persistent TD had a cumulative incidence of 4.8% after 1 year, 7.2% after 2 years, and 15.6% after 4 years. Taken individually, both antipsychotic drug dose, entered as a time-dependent covariate, and poor response to treatment of the first psychotic episode were significant predicters of time to TD. When antipsychotic drug dose and treatment response were examined together, treatment responders had significantly lower hazards for presumptive TD than nonresponders (hazard ratio, 0.29; 95% confidence interval, 0.09 to 0.97). Dose was a trend-level predicter, with each 100-mg chlorpromazine equivalent unit increase in dose associated with a 5% increase in the hazard of presumptive TD (hazard ratio, 1.05; 95% confidence interval, 0.99 to 1.11). CONCLUSION: Poor response to the treatment of a first episode of psychosis and, to a lesser extent, antipsychotic drug dose are important factors in the development of TD. This suggests that there may be a disease-related vulnerability to TD manifest with antipsychotic drug exposure. Potential pathophysiologic factors might include neurodevelopmentally induced structural neuropathologic characteristics, sensitization of nigrostriatal dopamine neurons, and the induction of glutamatergically mediated neurotoxic effects.

Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder.

BACKGROUND: We examined relapse after response to a first episode of schizophrenia or schizoaffective disorder. METHODS: Patients with first-episode schizophrenia were assessed on measures of psychopathologic variables, cognition, social functioning, and biological variables and treated according to a standardized algorithm. The sample for the relapse analyses consisted of 104 patients who responded to treatment of their index episode and were at risk for relapse. RESULTS: Five years after initial recovery, the cumulative first relapse rate was 81.9% (95% confidence interval [CI], 70.6%-93.2%); the second relapse rate was 78.0% (95% CI, 46.5%-100.0%). By 4 years after recovery from a second relapse, the cumulative third relapse rate was 86.2% (95% CI, 61.5%-100.0%). Discontinuing antipsychotic drug therapy increased the risk of relapse by almost 5 times (hazard ratio for an initial relapse, 4.89 [99% CI, 2.49-9.60]; hazard ratio for a second relapse, 4.57 [99% CI, 1.49-14.02]). Subsequent analyses controlling for antipsychotic drug use showed that patients with poor premorbid adaptation to school and premorbid social withdrawal relapsed earlier. Sex, diagnosis, obstetric complications, duration of psychotic illness before treatment, baseline symptoms, neuroendocrine measures, methylphenidate hydrochloride challenge response, neuropsychologic and magnetic resonance imaging measures, time to response of the initial episode, adverse effects during treatment, and presence of residual symptoms after the initial episode were not significantly related to time to relapse. CONCLUSIONS: There is a high rate of relapse within 5 years of recovery from a first episode of schizophrenia and schizoaffective disorder. This risk is diminished by maintenance antipsychotic drug treatment.

The early stages of schizophrenia: speculations on pathogenesis, pathophysiology, and therapeutic approaches.

Schizophrenia is commonly considered a neurodevelopmental disorder that is associated with significant morbidity; however, unlike other neurodevelopmental disorders, the symptoms of schizophrenia often do not manifest for decades. In most patients, the formal onset of schizophrenia is preceded by prodromal symptoms, including positive symptoms, mood symptoms, cognitive symptoms, and social withdrawal. The proximal events that trigger the formal onset of schizophrenia are not clear but may include developmental biological events and environmental interactions or stressors. Treatment with antipsychotic drugs clearly ameliorates psychotic symptoms, and maintenance therapy may prevent the occurrence of relapse. The use of atypical antipsychotic agents may additionally ameliorate the pathophysiology of schizophrenia and prevent disease progression. Moreover, if treated properly early in the course of illness, many patients can experience a significant remission of their symptoms and are capable of a high level of recovery following the initial episode. Because the clinical deterioration that occurs in schizophrenia may actually begin in the prepsychotic phase, early identification and intervention may favorably alter the course and outcome of schizophrenia.

Striatal enlargement in rats chronically treated with neuroleptic.

BACKGROUND: Striatal enlargement with chronic neuroleptic treatment in schizophrenic patients has been reported by several investigators. Longitudinal magnetic resonance imaging studies of patients suggest that changes in striatal volume may be caused by treatment with antipsychotic medication. METHODS: We have examined the effects of chronic neuroleptic treatment on postmortem striatal volume in the laboratory rat and have examined the relationship between striatal volume and vacuous chewing movements (VCMs). Autoradiographs of 50 rats treated with haloperidol (1.5 mg/kg/day) or drug free for varying durations of time (1-12 months) were utilized in this analysis. RESULTS: Chronic treatment with neuroleptics (1 month or greater) was associated with larger striatal volumes. The increase in striatal volume was present at 1 month of treatment and was sustained to 12 months of treatment. Rats that developed the high-VCM syndrome had larger striatal volumes than both drug-free and low-VCM rats, while low-VCM rats had larger striatal volumes than drug-free rats. CONCLUSIONS: These data suggest that chronic neuroleptic treatment is the cause of striatal enlargement in the laboratory rat, and that this enlargement is most prominent in rats that have the high-VCM syndrome.

Longitudinal study of brain morphology in first episode schizophrenia.

BACKGROUND: Beginning with Kraepelin, schizophrenia has been viewed as a progressive disorder. Although numerous studies of the longitudinal course of schizophrenia have demonstrated the clinical deterioration that occurs predominantly in the early stages of the illness, the pathophysiology of this clinical phenomenon has not been established. This aspect of the illness may be of critical importance to understanding the pathogenesis of schizophrenia and determining preventive therapeutic strategies. Abnormalities in brain morphology have been consistently described in schizophrenia, but it is not known when in the natural history of the illness they arise and whether they are progressive. Previous studies of brain morphology have been inconclusive, in part because of the variability of methods for image acquisition and analysis, assessment of patients already at chronic stages of their illness with extensive prior treatment exposure, and inadequate periods of follow-up. METHODS: To address these questions we examined 107 patients in their first episode of schizophrenia or schizoaffective disorder and 20 healthy volunteers using high resolution magnetic resonance imaging (MRI) and clinical assessments of psychopathology and treatment outcome for periods of up to 6 years. Fifty-one patients and 13 control subjects had MRIs after at least 12 months of follow-up. RESULTS: Results confirm the findings of ventricular enlargement and anterior hippocampal volume reductions in first episode schizophrenia patients that have been previously reported. In addition, we found changes in selected structures over time in relation to treatment outcome, including increases in ventricular volume that were associated with poor outcome patients. Contrary to our hypothesis, there were no significant reductions in cortical and hippocampal volumes over time. CONCLUSIONS: The finding of progressive ventricular enlargement in patients with poor outcome schizophrenia is consistent with the hypothesis that persistent positive and negative symptoms result in progressive brain changes in the form of ventricular enlargement, possibly due to neurodegeneration rather than the confounding effects of treatment. Future studies of first episodes of schizophrenia should utilize higher resolution imaging techniques that compare clinically well characterized patients with and without poor outcome and recurrent symptoms to control subjects who are well matched to patients for age and gender. There is also a need to control for treatment effects of typical antipsychotic medication on brain structure.

Serotonergic basis of antipsychotic drug effects in schizophrenia.

Recent attention has been focused on the involvement of serotonin (5-HT) in the pathophysiology of schizophrenia and its role in mediating antipsychotic drug effects. There are two reasons for the new emphasis: the tremendous success of the so-called "atypical" antipsychotic drugs (a common feature of which is their high affinity for specific 5-HT receptor subtypes); and the elucidation of a complex family of 5-HT receptors whose function and pharmacology is only beginning to be understood. This paper will review the evidence that pertains to the role of 5-HT in mediating antipsychotic drug effects. The interaction of dopamine and 5-HT systems will be reviewed, and the mechanisms of action of atypical antipsychotic drugs will be evaluated in this context. The impact of serotonin on neurodevelopment, and the involvement of serotonin in the psychotomimetic and psychotogenic properties of hallucinogens, will be discussed. Together, these facts will be placed into the context of changes in serotonergic function in schizophrenia.

Effectiveness of second-generation antipsychotics in patients with treatment-resistant schizophrenia: a review and meta-analysis of randomized trials.

OBJECTIVE: The authors conducted a review and meta-analysis of studies that compared the efficacy and tolerability of typical and second-generation antipsychotics for patients with treatment-resistant schizophrenia. METHOD: A systematic search revealed 12 controlled studies (involving 1,916 independent patients), which were included in the review. For the seven studies that compared clozapine to a typical antipsychotic, a meta-analysis was performed to examine clozapine's effects on overall psychopathology, response rate, extrapyramidal symptoms, and tardive dyskinesia. RESULTS: The meta-analysis confirmed that treatment-resistant schizophrenic patients have more favorable outcomes when treated with clozapine rather than a typical antipsychotic, as reflected by Brief Psychiatric Rating Scale total score, categorical response rate, Scale for the Assessment of Negative Symptoms score, Simpson-Angus Rating Scale score, and compliance rate. Clozapine also conferred benefits on the sickest treatment-resistant schizophrenic patients. Patients treated with olanzapine also had more favorable outcomes with regard to categorical response and compliance rates. CONCLUSIONS: In the aggregate, the results of a meta-analysis indicated that clozapine exhibits superiority over typical antipsychotics in terms of both efficacy (as measured by improvement in overall psychopathology) and safety (in terms of reduced extrapyramidal side effects). However, the magnitude of the clozapine treatment effect was not consistently robust. Efficacy data for other second-generation antipsychotics in the treatment of patients with refractory schizophrenia were inconclusive. There is, therefore, a growing need to consider new and different treatment strategies, whether they be adjunctive or monotherapeutic, for schizophrenia that continues to be resistant or only partially responsive to treatment.

Relation of plasma fluphenazine levels to treatment response and extrapyramidal side effects in first-episode schizophrenic patients.

OBJECTIVE: The aim of this study was to determine the relation between plasma fluphenazine levels and clinical response in first-episode schizophrenic patients. METHOD: Data from 36 first-episode schizophrenic or schizoaffective inpatients diagnosed according to the Research Diagnostic Criteria were evaluated. The patients received open, standardized treatment with fluphenazine, 20 mg/day, for at least 4 weeks. Psychopathology was assessed biweekly, and plasma fluphenazine levels were ascertained weekly. Patients were classified as responders or nonresponders, and correlations between their neuroleptic levels and ratings of psychopathologic and extrapyramidal symptoms were computed. RESULTS: Plasma fluphenazine levels for weeks 1 through 4 were significantly correlated with each other but were not correlated with age, gender, diagnosis, or race. Mean neuroleptic levels (weeks 3 and 4) were not different between responders and nonresponders and were not correlated with measures of psychopathology or extrapyramidal symptoms. CONCLUSIONS: These results do not indicate an association between plasma fluphenazine levels and response to treatment or extrapyramidal side effects in first-episode schizophrenia. The disparity between the results of this study and those of previous studies may be due to methodological differences or to a biologically based difference between first-episode and chronic patients.

Depression in first-episode schizophrenia.

OBJECTIVE: Because findings regarding the prognostic significance of depressive symptoms in schizophrenia and their effect on the course and treatment of schizophrenia have been limited by the effects of previous treatment, retrospective evaluations, and differing definitions and criteria, the authors sought to determine the prevalence and prognostic significance of depressive symptoms in first-episode schizophrenia. METHOD: Thirty-nine men and 31 women experiencing their first episode of schizophrenia were evaluated with behavioral and extra-pyramidal symptom scales before treatment (baseline), biweekly during acute treatment, and then monthly. Extracted scores on the Hamilton Rating Scale for Depression and a "syndromal" definition of depression based on Research Diagnostic Criteria were obtained. Patients were followed prospectively for up to 5 years and received open standardized treatment. RESULTS: The prevalence of depressive symptoms at baseline ranged from 75% (patients who met extracted Hamilton and/or syndromal criteria) to 22% (patients who met both criteria). Of 808 psychotic ratings given to the 70 patients over a 5-year follow-up period, 210 (26%) were concurrently rated as depressed; of the 1,754 nonpsychotic ratings, only 70 (4%) were concurrently rated as depressed. Of the 210 depressive symptoms that occurred concurrently with psychosis, 206 (98%) resolved as the psychosis remitted. Depressive symptoms were prodromal to a psychotic relapse in only two (7%) of 27 patients who relapsed. Depressive symptoms correlated more with positive and negative symptoms than with extrapyramidal symptoms. CONCLUSIONS: These findings suggest that depressive symptoms in patients experiencing their first episode of schizophrenia may represent a core part of the acute illness or may occur as a subjective reaction to the experience of psychotic decompensation. Since most of the depressive symptoms resolved as the psychosis remitted, antidepressant therapy should be limited to patients in whom the depression persists.

Prevalence and clinical correlates of extrapyramidal signs and spontaneous dyskinesia in never-medicated schizophrenic patients.

OBJECTIVE: This study assessed the prevalence of extrapyramidal signs and spontaneous dyskinesia in neuroleptic-naive, first-episode schizophrenic patients and examined the clinical correlates. METHOD: In a prospective study of the psychobiology of schizophrenia, the authors examined 89 neuroleptic-naive patients for the presence of extrapyramidal signs by using the Simpson-Angus Rating Scale and for dyskinesia by using the Tardive Dyskinesia Rating Scale. RESULTS: Fifteen patients (16.9%) had extrapyramidal signs, but only one had spontaneous dyskinesia at baseline. Presence of extrapyramidal signs was correlated with more negative symptoms and poorer treatment outcome that was reflected in a longer time to and lower level of remission. There was no correlation of spontaneous extrapyramidal signs with age of patient, age at onset of psychotic symptoms, or baseline psychopathology. There was no difference between patients with and without spontaneous extrapyramidal signs in terms of the subsequent development of persistent tardive dyskinesia, but the patients with spontaneous extrapyramidal signs were more likely to develop parkinsonian side effects after 8 weeks of antipsychotic treatment. CONCLUSIONS: Extrapyramidal signs are present in a proportion of neuroleptic-naive, first-episode schizophrenic patients, which suggests an involvement of these signs in the schizophrenic process that probably reflects basal ganglia pathology. The presence of spontaneous extrapyramidal signs seems to have prognostic significance insofar as it is linked to a poorer outcome and longer time to remission. Spontaneous dyskinesia appears to be a relatively rare finding.

Increase in caudate nuclei volumes of first-episode schizophrenic patients taking antipsychotic drugs.

OBJECTIVE: This study examined the pathomorphology of the caudate nuclei in first-episode schizophrenic patients with minimal previous neuroleptic exposure. METHOD: Magnetic resonance imaging (MRI) of the brain was used to examine longitudinally the caudate pathomorphology in 29 first-episode schizophrenic patients and 10 healthy comparison subjects. MRI scans were obtained after the subjects entered the study and at 18-month follow-up. The patients were treated with standardized neuroleptic regimens during the 18-month period. Volumetric assessments of the cerebral cortex, lateral ventricles, and caudate nuclei were performed on T1-weighted coronal brain sections. In addition, the patients were systematically evaluated for psychopathology at baseline and during treatment. RESULTS: Caudate volumes increased 5.7% in the patients during the 18-month treatment interval, whereas they decreased 1.6% in the comparison subjects over the same time period. Greater amounts of antipsychotic medication received by patients before the first scan and younger age at the time of the first scan were associated with larger increases in caudate volume. CONCLUSIONS: Caudate enlargement occurs early in the course of treatment in young first-episode schizophrenic patients. This may be a result of an interaction between neuroleptic treatment and the plasticity of dopaminergic neuronal systems in young patients.

Gender differences in onset of illness, treatment response, course, and biologic indexes in first-episode schizophrenic patients.

OBJECTIVE: Gender differences in onset of illness, response to treatment, course, and biologic measures have been consistently reported in patients with chronic schizophrenia. Patients with first-episode schizophrenia were examined to determine whether gender differences also occur in these patients. METHOD: Fifty-four neuroleptic-naive schizophrenic patients (29 men and 25 women) were studied beginning in an initial stage of the first hospitalization for psychosis while undergoing treatment with a standardized medication regimen. Before antipsychotic drug treatment and during 1 year of follow-up each patient was rated on the Schedule for Affective Disorders and Schizophrenia--Change Version (psychosis and disorganization items), Scale for the Assessment of Negative Symptoms, Clinical Global Impression, modified Simpson Tardive Dyskinesia Scale, and Simpson-Angus Rating Scale for extrapyramidal side effects. Methylphenidate challenge testing was done at study entry. Plasma neuroleptic, homovanillic acid (HVA), and prolactin levels were determined weekly for the first 6 weeks. RESULTS: The female schizophrenic patients had a later onset and better treatment response than the men. Plasma HVA levels at baseline and week 1 and changes in prolactin levels from baseline to weeks 1 through 6 were greater among the women. CONCLUSIONS: Gender differences in onset and degree of treatment response in first-episode schizophrenic patients are similar to those of chronic patients and are apparent at early stages of the illness. The greater pharmacologic responsivity of the female patients, as indicated by the neuroendocrine results, is consistent with the gender difference in degree of symptom improvement with medication.

Predictors of treatment response from a first episode of schizophrenia or schizoaffective disorder.

OBJECTIVE: This study examined the treatment response of patients with first-episode schizophrenia and schizoaffective disorder and potential predictors of response. METHOD: First-episode patients were assessed on measures of psychopathology, cognition, social functioning, and biological parameters and treated according to a standardized algorithm. RESULTS: One hundred eighteen patients (52% male, mean age 25.2 years) entered the study. The cumulative percentage of patients responding by 1 year was 87%; the median time to response was 9 weeks. The following variables were significantly associated with less likelihood of response to treatment: male sex, obstetric complications, more severe hallucinations and delusions, poorer attention at baseline, and the development of parkinsonism during antipsychotic treatment. Variables not significantly related to treatment response were diagnosis (schizophrenia versus schizoaffective disorder), premorbid functioning, duration of psychotic symptoms prior to study entry, baseline disorganization, negative and depressive symptoms, baseline motor function, akathisia and dystonia during treatment, growth hormone and homovanillic acid measures, psychotic symptom activation to methylphenidate, and magnetic resonance measures. CONCLUSIONS: Patients with first-episode schizophrenia and schizoaffective disorder have high rates of response to antipsychotic treatment; there are specific clinical and pathobiologic predictors of response.

The behavioral effect of m-chlorophenylpiperazine (mCPP) and methylphenidate in first-episode schizophrenia and normal controls.

Although there has been renewed interest in the serotonin (5-HT) system in schizophrenia, direct evidence for 5-HT dysfunction is limited. This study compares the responses of m-chlorophenyl-piperazine (mCPP), a 5-HT agonist, in first-episode schizophrenia and a known psychotogenic dopamine agonist, methylphenidate. Eighteen patients experiencing their first episode of psychosis and eight healthy controls received methylphenidate (0.5 mg/kg) and mCPP (0.1 mg/kg) intravenously. Behavioral assessments were done before and after the procedure, and a peak response to each agent was rated. Methylphenidate, but not mCPP, produced psychotic symptoms in patients. mCPP did decrease anxiety, hallucinations, and anger and increased agitation, somatic concern, and impaired understandability. Both agents had limited effects on controls. In conclusion, unlike methylphenidate, mCPP did not produce psychotic symptom activation in schizophrenic patients in, and its effects appeared to be nonspecific.

Psychobiologic correlates of treatment response in schizophrenia.

In studies conducted on largely treatment naive patients in their first episode of psychosis, we have found that treatment outcome is quite good and that most patients recover or at least achieve a substantial degree of symptom remission. However, over the course of their illness and in the context of subsequent psychotic episodes, they may experience some decrease in their treatment response from illness progression. In addition, the heterogeneity of treatment outcome is associated with specific clinical (gender, primary negative symptoms of the deficit state, duration of psychosis) and biological variables (pHVA, ventricular volume). It is unclear whether these variables represent aspects of discrete subtypes of schizophrenia or dimensional measures of pathology within the broad context of a unitary disease entity.

Cerebral morphometry and clozapine treatment in schizophrenia.

Studies of brain morphology in schizophrenia may be informative about basic pathophysiologic processes, provide clinically useful indicators of treatment response, and lead to the identification of markers for selective treatment effects. This paper reviews findings from magnetic resonance imaging studies of patients with schizophrenia conducted at Hillside Hospital, with special attention to (1) findings that have helped distinguish patients who respond well to typical neuroleptics from those who have gone on to trials of clozapine, (2) the capacity of morphological measures to predict clozapine treatment response, and (3) the possibility that selective hypertrophy of striatal structure may be caused by chronic treatment with typical neuroleptics, but not by clozapine.

Factors influencing treatment response and outcome of first-episode schizophrenia: implications for understanding the pathophysiology of schizophrenia.

For the majority of patients, schizophrenia is a chronic recurrent disease that leads to significant residual morbidity which occurs through a process of behavioral deterioration. The factors that influence the course of schizophrenia after its onset and the ability of treatment to modify the effects of the patient's illness are not well understood. This article examines specific clinical and biological variables that are associated with treatment response and outcome. These variables, which are both trait and state dependent, include premorbid adjustment, age and mode of onset of illness, gender, duration of psychosis, schizophrenia subtype, primary negative symptoms, and extrapyramidal signs including tardive dyskinesia and plasma HVA and brain pathomorphology. In addition, the chronic effects of antipsychotic drug treatment may influence illness course both favorably and adversely as well as potentially altering the neurobiological substrates that mediate expression of the illness and treatment response. Finally, the question of whether the active phase of the illness involves a pathologic process that leads to illness progression is discussed. In light of this discussion, we can speculate that although certain aspects of the illness in terms of its severity and course may be, to an extent, predetermined, a number of factors can exert favorable and unfavorable effects on the course of the illness and its ultimate outcome. One question for the field is to develop therapeutic strategies that minimize the morbidity of the illness in a way that does not introduce iatrogenic consequences to the patient.

IQ scores of treatment-resistant schizophrenia patients before and after the onset of the illness.

In this study we examined the correlations of actual pre-morbid IQ scores (obtained from routine educational assessments) and estimated current IQ scores in 27 treatment-resistant schizophrenia patients. Pre-morbid (mean = 93) and current (mean = 83) IQ scores were significantly correlated (r = 0.807, P < 0.0001), while duration of illness (10-40 years) was unrelated to the magnitude of IQ score decline (r = -0.103, P = 0.575). These data suggest that pre-morbid IQ test scores are highly predictive of post-morbid scores.

Emerging roles for novel antipsychotic medications in the treatment of schizophrenia.

Antipsychotic medications are the mainstay of treatment for schizophrenia. The recent advent of atypical antipsychotics has provided new clinical options and set higher expectations for the treatment of schizophrenia. It is not yet clear how each different drug will fit within the therapeutic armamentarium and this lack is most evident with considering patients with treatment refractory schizophrenia. On the other hand, the expectation of superior efficacy, more benign side effect profile and potential to impact the longitudinal course of schizophrenia provide a rationale for the use of novel antipsychotics as a first-line treatment of schizophrenia.