An international perspective on assessment of negative and positive symptoms in schizophrenia

Central D2receptor blockade and antipsychotic effects of neuroleptics. Preliminary study with positron emission tomography

The striatal D2receptor density/affinity index was assessed using positron emission tomography and76Br-Bromolisuride in 15 schizophrenics, first untreated, and afterwards receiving neuroleptics, and in 14 control subjects. The patients received low or conventional doses of neuroleptics. The schizophrenics receiving low doses (n= 6) had preponderant negative symptoms. Mean D2receptor occupancy was 24 ± 20%. Despite this weak central D2receptor blockade, a significant decrease in negative symptoms was observed, a result consistent with the hypothesis of a disinhibitory action of some neuroleptics administered in low doses. The patients treated with conventional doses (n= 9) had mixed positive and negative symptoms, and the mean D2receptor occupancy was 54 ± 13%. Significant decreases in positive symptoms, but also in negative symptoms, were obtained with this treatment. Before treatment, there was no significant difference in the striatal D2receptor density/affinity index between: 1) patients and controls, 2) negative and mixed schizophrenics, and 3) the subsequent responder and non-responder patients. In addition, the D2dopamine receptor occupancy by neuroleptics did not significantly differ in responder or nonresponder patients, suggesting that the central D2dopamine receptor blockade is a necessary, but insufficient condition to account for the antipsychotic effect of neuroleptics.

Cortical metabolic patterns in schizophrenia: a mismatch with the positive-negative paradigm

The cortical metabolic patterns of 12 schizophrenics experiencing hallucinations and/or pseudo-hallucinations were investigated using positron tomography and 18F-fluoro-deoxy-glucose. Andreasen's scales were scored and the patients (all “mixed“) were classified in a “positive” or a “negative” group and compared to a group of 6 normal controls. The data were analyzed across groups for absolute metabolic rates, metabolic indices (cortical region/whole studied cortex), and specific indices exploring the sensory non-association/posterior parietal association and the prefrontal association/posterior parietal association dimensions. Whole-cortex metabolic rate in the negative group was found to be lower than both the control (P=0.02) and the positive group (P = 0.002) while the positive group did not differ significantly from the controls. We found “hypofrontality” to be without difference between the positive and the negative group (controls: 7±0.7, positive: 5.9±0.2, negative: 4.9±0.15, mean±SEM in mg/min/100 g). However, the prefrontal association/posterior parietal association ratio was increased in the negative group (P=0.02). A major finding was an increase in the posterior non-association/posterior parietal association ratio in the whole schizophrenic group as compared to the controls (P = 0.004), this being more marked in the negative (P=0.01) than in the positive group. Arguments are given to support the hypothesis that this particular increase could be related to the hallucinatory activity of the patients.

Rating scale for the assessment of communication disorders in schizophrenics

Taking up the Bleulerian view of a clinical description based on a pathogenic model, we propose a rating scale for the assessment of communication disorders in schizophrenic patients. The scale consists of clinical items that could be the direct expression of the three hypotheses of cognitive dysfunction which have been postulated to explain communication dysfunction in these patients. We assessed the frequency of the 16 items in the scale in a total of 80 subjects (43 schizophrenic subjects, ten manic subjects, 17 depressive subjects and ten normal control subjects). The results of this study showed that this item schedule was specific to schizophrenic patients and, in particular, could statistically significantly discriminate schizophrenic patients from psychotic patients with affective disorder. The methodological qualities of the scale were explored and proved accurate, except for the reliability which is too low for some items and the item-to-total correlation which is too low for one item of the scale.

The Scale for the Assessment of Negative Symptoms (SANS): Conceptual and Theoretical Foundations

The Scale for the Assessment of Negative Symptoms (SANS) was the first instrument developed in order to provide for comprehensive assessment of negative symptoms in schizophrenia (Andreasen, 1982, 1983). It consists of five scales that evaluate five different aspects of negative symptoms: alogia, affective blunting, avolition-apathy, anhedonia-asociality, and attentional impairment. Each of these negative symptoms can be rated globally, but in addition detailed observations are made in order to achieve the global rating. It is complemented by a Scale for the Assessment of Positive Symptoms (SAPS), which permits detailed evaluation and global ratings of hallucinations, delusions, positive formal thought disorder and bizarre behaviour (Andreasen, 1984). Taken together, the two scales provide a comprehensive set of rating scales in order to measure the symptoms of schizophrenia and to assess their change over time.

Can we combine symptom scales for collaborative research projects?

Collaborative research projects have the potential to answer important research questions, which may otherwise require huge resources, funding, and time to complete. There are several scales for measuring psychotic symptoms in schizophrenia and other psychotic disorders, with the Scale for Assessment of Positive Symptoms (SAPS), Scale for Assessment of Negative Symptoms (SANS), Positive and Negative Symptom Scale (PANSS), and the Brief Psychiatric Rating Scale (BPRS) being among the most commonly used. High quality research efforts have used these three scales in different projects, and in order to merge study efforts, some means of combining data from these scales may be necessary. We reviewed correlations in published studies for these three scales, finding them to be highly correlated, however on comparison of the three scales there were considerable clinical differences between them. The paper discusses potential methods for combining the scales in collaborative research, including use of the recently developed standardised remission criteria for schizophrenia.

Impact of the Fragile X mental retardation 1 (FMR1) gene premutation on neuropsychiatric functioning in adult males without fragile X-associated Tremor/Ataxia syndrome: a controlled study

Fragile X Syndrome is the most common heritable form of mental retardation caused by silencing of the FMR1 gene, which arises from intergenerational trinucleotide repeat expansion leading to full mutation. An intermediary carrier condition, known as the premutation, is characterized by expansion up to 200 repeats without concomitant gene silencing. This prevalent allelic variant was initially thought to be free of phenotypic effects. However, recent reports have identified a degenerative disease, Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) in older men as well as premature ovarian failure in women. Previously reports are inconsistent regarding the neuropsychiatric phenotype associated with premutation due to small sample sizes, ascertainment bias, lack of adequate control groups, administration of measures with poor psychometric properties, and the confounding effects of FXTAS. We addressed these problems by conducting a controlled study of male carriers (n = 40) of the premutation without manifest symptoms of FXTAS, comparing their responses on specific, reliable, and valid measures of neuropsychiatric functioning to those of individuals with shared family environment (n = 22) and non-carrier comparison males (n = 43). Multivariate analyses revealed that the premutation confers significant risk for working memory difficulties, an associated feature of Attention-Deficit Disorder. Furthermore, both the family controls and men with premutation exhibited higher rates of Alcohol Abuse as compared to non-carrier control men. These findings highlight the importance of recognizing the distinct phenotypic outcomes that characterize the Fragile X premutation and the subtle risk factors that can act as precursors to more significant psychiatric impairment.

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.

Diagnosing delusions: a review of inter-rater reliability

Although several studies have examined the reliability of diagnosing delusions there is no comprehensive review of the literature. Therefore, the reliability of diagnosing 'delusions in general' and the subcategory of 'bizarre delusions' was reviewed, including both structured interview and standardized instrument methods. The literature suggests that delusions in general can be diagnosed reliably with both structured interview and standardized instruments. However, bizarre delusions are not reliably diagnosed by either, suggesting that this concept may have little clinical validity. Nevertheless, many of the studies reviewed are poorly designed or subject to significant confounds. Criteria are suggested for adequate future studies.

Forty-two-years later: the outcome of childhood-onset schizophrenia

This paper describes the long-term course of 76 patients who had been consecutively admitted to the Department of Child and Adolescent Psychiatry, Philipps University, between 1920 and 1961 with a suspected diagnosis of childhood-onset schizophrenia. By means of a consensus analysis of available data in accordance with ICD-10 criteria, the diagnosis of schizophrenia was confirmed in only 50% of the original sample (n = 38, childhood-onset schizophrenia group); whereas the rest of the sample were allotted other diagnoses (n = 38, non-schizophrenia group). A follow-up investigation was conducted, interviewing all available patients, if possible, or their first-degree relatives or doctors. In the childhood-onset schizophrenia group, age at onset (mean +/- S.D.) was 12.7 +/- 2.5 (range 5-14) years and age at follow-up was 55.0 +/- 4.8 (range 42-62) years. The outcome of this group was poor. According to the Global Assessment Scale (GAS), only 16% had a good (GAS score 71-100) and 24% had a moderate (GAS score 41-70) outcome. In the 16 childhood-onset schizophrenia patients who could be personally investigated at follow-up, 10 (62.5%) displayed severe or moderate depressive symptoms according to the BPRS depressive score. The death rate (including suicide) was significantly higher in the schizophrenia group (n = 15; 39.5%) than in the non-schizophrenia group (n = 7; 18.4%). A comparison of the life-time diagnoses of the total sample (n = 76) at follow-up with the ICD-10 diagnoses made retrospectively revealed a diagnostic stability in 69 (91%) and a change of diagnosis in 7 (9%) cases, among them 4 who were originally diagnosed as having childhood-onset schizophrenia.

The factor structure for the Positive and Negative Syndrome Scale (PANSS) in recent-onset psychosis

The Positive and Negative Syndrome Scale (PANSS) is a widely used instrument for measuring severe psychopathology in adult patients with schizophrenia. Data, primarily on chronic patients, have been used to define factors for the PANSS. The present study examines the PANSS factor structure in a large sample of subjects with recent-onset schizophrenia, schizophreniform disorder and schizoaffective disorder who had been exposed to very limited antipsychotic medication. Equamax factor analysis was conducted on PANSS baseline assessments from a multicenter, 11 country drug trial that enrolled 535 patients. The forced five-factor solution essentially corresponds to the factors most frequently described previously, namely negative, positive, disorganized (or cognitive), excited and anxiety/depression. In the exploratory analysis, a seven-factor solution was obtained, with depression and anxiety symptoms separating and a motor component emerging. The results of this study partially support the use of a five-factor model for the PANSS, but suggest that scales for catatonia, depressive and anxiety syndromes should be included in future studies.

The factor structure for positive and negative symptoms in South African Xhosa patients with schizophrenia

Most studies investigating the symptom dimensions of schizophrenia utilising the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS) favour a three factor model. This study sought to investigate the factor structure of both the global and individual items of the SANS and SAPS in a large sample of South African Xhosa patients with schizophrenia. A total of 422 subjects participated. Both principal components and factor analytical procedures were applied. For the global items, a two-factor solution representing positive and negative symptoms accounted for 59.9% of the variance. Alternatively, the three-dimensional model of negative, psychotic and disorganisation factors was supported by a five-factor solution if the more heterogeneous items of attention and alogia were ignored. Analysis of the individual items yielded a five-factor solution with the negative symptoms splitting into diminished expression and disordered relating, and the positive symptoms separating into factors for psychosis, thought disorder and bizarre behaviour. Our findings are very similar to those from other parts of the world, providing evidence that the factor structure for the symptoms of schizophrenia is relatively resistant to cultural influences. This is particularly true for negative symptoms.

Defining the phenotype of schizophrenia: cognitive dysmetria and its neural mechanisms

All research on schizophrenia depends on selecting the correct phenotype to define the sample to be studied. Definition of the phenotype is complicated by the fact that there are no objective markers for the disorder. Further, the symptoms are diverse, leading some to propose that the disorder is heterogeneous and not a single disorder or syndrome. This article explores an alternative possibility. It proposes that schizophrenia may be a single disorder linked by a common pathophysiology (a neurodevelopmental mechanism), which leads to a misconnection syndrome of neural circuitry. Evidence for disruption in a specific circuit is explored: the cortical-thalamic-cerebellar-cortical circuit (CCTCC). It is suggested that a disruption in this circuit leads to an impairment in synchrony, or the smooth coordination of mental processes. When synchrony is impaired, the patient suffers from a cognitive dysmetria, and the impairment in this basic cognitive process defines the phenotype of schizophrenia and produces its diversity of symptoms.

Blood biogenic amines during clozapine treatment of early-onset schizophrenia

The aims of this investigation were to evaluate long-term and short-term effects of clozapine-treatment on plasma biogenic amines and psychopathology measures in adolescents with schizophrenia (DSM-III-R criteria). The long-term study was conducted in a study sample of 40 young patients (age 14-22 years) following a mean of 3.4 years of neuroleptic treatment. During the study, 20 patients received clozapine, and the other 20 patients were treated with standard neuroleptic medications. At the beginning of the open clinical trials, the patients had already been receiving clozapine treatment for 24 +/- 15 months. Assessment of the biochemical and psychopathological measures was performed on six occasions at consecutive 6-week intervals during maintenance treatment with clozapine or conventional neuroleptics. Blood levels of serotonin, 3-methoxy-4-hydroxy-phenylglycol (MHPG), norepinephrine, and epinephrine were significantly higher in clozapine-treated patients than in conventionally treated patients. During long-term treatment, higher serotonin levels were associated with significantly fewer negative symptoms of schizophrenia, whereas higher MHPG levels were correlated with less depression. The short-term effects of clozapine were assessed in a second and independent study sample. After failing on conventional neuroleptics in clinical trials lasting a mean of 1.6 years, 15 inpatients (aged 11-20 years) received clozapine. Weekly ratings of psychopathological symptoms using standard rating scales were performed in parallel to blood samplings for measurements of biogenic amines and serum levels of clozapine. These measures were obtained for 6 weeks during conventional neuroleptic treatment and for 6 weeks during the open-label clozapine trial. Serum levels of serotonin and plasma norepinephrine levels were significantly higher during treatment with clozapine than during pretreatment with typical neuroleptics. A comparison of plasma epinephrine levels in responders (n = 7) and nonresponders (n = 8) to clozapine revealed that response to clozapine can be predicted by epinephrine levels prior to initiation of treatment with clozapine (responders ranging from 32.2 to 90.3 pg/ml; nonresponders ranging from 92.5 to 473.5 pg/ml). Additionally, subjects who responded to clozapine showed increased mean plasma concentrations of MHPG and epinephrine during treatment with this drug in comparison to the levels measured during pretreatment with typical neuroleptic medication. Nonresponders to clozapine failed to show this increase. Finally, in responders to clozapine a negative linear relationship between negative symptoms of schizophrenia and the concentrations of plasma norepinephrine and serum serotonin were observed. In conclusion, our results demonstrate that plasma epinephrine levels prior to initiation of clozapine therapy predict response to this atypical neuroleptic. Our findings derived from short-term and maintenance treatment with clozapine suggest involvement of norepinephrine, epinephrine and serotonin in the therapeutic actions of the atypical neuroleptic clozapine.

Schizophrenic syndromes and clozapine response in treatment-resistant schizophrenia

Relationships between symptom profile and clozapine response were studied. Symptom scores on the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms were subjected to principal component analysis (PCA) in a group of 66 treatment-resistant schizophrenic patients, 49 of whom were treated with clozapine. Factor scores were compared among responders, non-responders and partial responders. The PCA yielded a four-factor solution, with positive symptoms, negative symptoms, cognitive disorganization and behavioral disorganization components. Cognitive and behavioral disorganization syndrome scores showed significant differences across groups. Cognitive disorganization was higher in non-responders, while behavioral disorganization was higher in partial responders. The results support the possibility of using clinical profiles to predict therapeutic response to clozapine.

A study of the interrelationship between and comparative interrater reliability of the SAPS, SANS and PANSS

We assessed the comparative interrater reliability of the SANS/SAPS and PANSS as measures of symptomatology in schizophrenia and also examined the interrelationship between scores on these instruments. Two experienced raters used these Scales to assess positive and negative symptoms in a group of 85 patients with a DSM III-R diagnosis of schizophrenia. Ratings were based on structured clinical interviews, review of case notes and consultation with staff familiar with the patients. Comparable levels of interrater reliability were found for each system of measuring symptomatology, but levels of interrater reliability were on the whole lower than have been reported in the past. There were high correlations between overall indices of positive and negative symptomatology derived from the two measurement systems.

An empirical analysis of latent structures underlying schizophrenic symptoms: a four-syndrome model

Various models of schizophrenia have postulated two syndromes (i.e., positive and negative), although other exploratory factor analyses have suggested a disorganization syndrome. We conducted a confirmatory factor analysis (CFA) on Schedule for the Assessment of Positive Symptoms (SAPS) and Schedule for the Assessment of Negative Symptoms (SANS) items and subscales to assess the latent structure of symptoms reflecting underlying pathological processes. The sample included 253 DSM-IIIR schizophrenic inpatients. Fourteen different models with one, two, three, or four syndromes were compared using CFA for "goodness of fit." The three-syndrome models displayed better fitness than any of the one- or two-syndrome models. All of the three-syndrome models shared the positive and negative dimensions; the third dimension in these three-syndrome models was either the disorganization or Strauss' relational dimensions. In the reported data, a four-syndrome model, including positive, disorganization, negative, and relational dimensions, showed excellent fitness. Despite its limitations, this study suggests the need to explore the validity of a four-syndrome model. The positive-negative model fits poorly with the data.

Positive and negative symptoms of schizophrenia: past, present, and future

The "group of schizophrenias," normally referred to with a single nominative, is phenomenologically heterogeneous. Its symptoms represent multiple psychological domains, including perception, inferential thinking, language, attention, social interaction, emotion expression, and volition. Studies of psychopathology have simplified this complex array in several ways; one has been a subdivision into positive and negative symptoms. Reports by our group and others suggest that the symptoms of schizophrenia fall into three natural dimensions: positive symptoms subdivided into psychotic and disorganized dimensions, while a third negative dimension also emerges. Since these dimensions have impressive consistency across studies, future work must examine their relationship to clinically relevant concepts such as prognosis or etiology and examine four different aspects: longitudinal course, neural mechanisms, relationship to treatment, and interrelationships in other pathological conditions.

A latent structure analysis of the positive and negative symptoms in schizophrenia

Although previous studies have suggested the inadequacy of the two-factor models of positive and negative symptoms in schizophrenia, confirmatory testing of the putative three-factor models is needed. Using a sample of 193 individuals diagnosed with schizophrenia, this study tested the relative goodness-of-fit of one-, two-, and three-factor models of the positive and negative symptoms. Using confirmatory factor analysis (CFA), the three-factor model of Addington et al., Arndt et al., and Liddle and Barnes that specifies positive, negative, and disorganized factors had the best fit with the data. Allowing the factors to co-vary and specifying dimensionality to the negative symptoms substantially improved the fit of the model. The study addressed several other issues. First, whereas the correlation between positive and negative symptoms was modest, the disorganized symptoms were significantly and more strongly related to both the positive and negative symptoms. Second, depression was not correlated with negative symptoms, but was significantly related to both the positive and disorganized symptoms. Third, the relationships between the three factors and levels of global, social, and work functioning in the sample supported the criterion-related validity of the three-factor model.

Central D2 receptors and negative symptoms of schizophrenia

Most in vivo studies of striatal D2 receptor (SD2R) density with positron emission tomography in schizophrenia have attempted to relate this variable to the diagnosis of the illness. In the present study, a relationship between SD2R and clinical dimensions of this psychosis was searched for in a highly selected group of young negative schizophrenics (8 drug-naïve and 2 drug-free). The SD2R density index measured in vivo using 76Br-bromolisuride and PET correlated negatively (r = 0.80, P < 0.01) with a psychomotor dimension of schizophrenia involving blunted affect and alogia. The mean SD2R index of the patients did not differ from that of age-matched control subjects. Therefore, this behavioural dimension accounts for the variance of the SD2R, suggesting that the striatal dopamine system modulates symptoms such as flattened affect and alogia.

Alogia, attentional impairment, and inappropriate affect: their status in the dimensions of schizophrenia

Previous factor analyses have shown that at least three factors are needed to encompass the positive and negative symptoms of schizophrenia. Despite marked similarities across studies, it remains unclear whether certain symptoms such as alogia, attentional impairment, and inappropriate affect are more closely related to negative or positive symptoms. An exploratory analysis was undertaken of the separate items on the Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS) that constitute the global rating of alogia, as well as the global ratings of attentional impairment and inappropriate affect in 90 schizophrenic patients. Findings indicate that inappropriate affect loads significantly with bizarre behavior and positive formal thought disorder on a disorganization factor, whereas attentional impairment loads significantly on psychotic, disorganization, and negative symptom factors. The global rating of alogia appears to comprise both positive and negative symptoms, with the item poverty of content of speech loading on the disorganization factor, and other items such as poverty of speech, blocking, and increased latency loading on the negative symptom factor. It is concluded that three dimensions are needed to characterize the symptoms of schizophrenia as measured by the SAPS/SANS. The use of three dimensions may be a robust way to further explore the relationship between signs and symptoms and their underlying mechanisms in schizophrenia.

Are there more than two syndromes in schizophrenia? A critique of the positive-negative dichotomy

A sample of 115 DSM-III-R schizophrenics was studied by means of the SANS and SAPS. A factor analysis from the nine subscales and two symptoms (inappropriate affect and poverty of content) and a review of the previous factor analyses suggest that schizophrenic symptoms cannot be appropriately classified into positive and negative syndromes. The low internal consistency of the SAPS suggests that the positive symptoms are not a homogeneous syndrome. Our results fit better with Liddle's model of three syndromes (negative, delusion-hallucination and disorganisation syndromes). It is argued that we are far from a valid classification of schizophrenic symptoms and the positive-negative dichotomy appears to be an oversimplification.

Reliability and validity of the Chinese versions of the Scales for Assessment of Positive and Negative Symptoms

This 4-center study assesses the reliability and validity of the Chinese versions of the Scale for Assessment of Positive Symptoms and the Scale for Assessment of Negative Symptoms. Interrater reliability, short-term test-retest reliability, and internal consistency were excellent; intraclass correlation coefficients and Cronbach alphas for the overall scores were all over 0.8. The strong correlation of the scales with an independently assessed parallel measure (the Chinese version of the Brief Psychiatric Rating Scale) and the separate positive and negative factors found with principal components analysis confirm the construct validity of the instruments. These findings demonstrate the importance of culturally sensitive revision and rigorous psychometric evaluation of Western instruments prior to their use in non-Western cultures.

Negative symptoms in chronic schizophrenia. Relationship to duration of illness

The frequency and distribution of negative symptoms in a sample of 40 patients admitted to hospital with RDC-definite schizophrenia were examined. There was a highly significant positive correlation between negative symptom scores obtained using three different rating scales, but the presence of negative symptoms was not significantly related to duration of illness or number of episodes of illness. These findings do not support a model of negative symptoms being the consequence of schizophrenic relapse, but are in favour of their being an integral component of the schizophrenic syndrome, as salient in the first as in later episodes.

Changes in the positive and negative symptoms of schizophrenic in-patients in China

Positive and negative symptoms at admission and discharge of 401 unselected schizophrenic patients from four psychiatric hospitals around China were studied. On admission 58% of patients had prominent negative symptoms and the overall severity of negative symptoms was similar to that of positive symptoms; at discharge, negative symptoms were more prevalent and more severe. The severity of negative symptoms was not significantly correlated with duration of illness or with dosage of medication; 48% of first-episode, drug-naive patients had prominent negative symptoms on admission. Negative symptoms responded to standard neuroleptic treatment, but the improvement was less marked than that in positive symptoms (47% v. 80%). The proportion of patients classified as positive type, negative type, and mixed type schizophrenia altered dramatically with treatment. These findings highlight the importance of negative symptoms in the assessment and treatment of both acute and chronic schizophrenia.

Correlation of negative symptoms in schizophrenia with frontal lobe parameters on magnetic resonance imaging

Among 24 chronic schizophrenic patients, the 10 with high ratings for negative symptoms had significantly higher left-frontal: temporal-cortical T2 ratios. This finding was unrelated to age, dose of medication, length of illness or handedness. No T1 or T2 changes were found to be associated with positive symptoms or tardive dyskinesia in the regions examined.

Neuroleptic-resistant schizophrenics

According to Crow's postulated positive-negative distinction, negative symptoms of schizophrenia are less responsive to neuroleptic drugs. Not all research evidence supports that expectation, however, so that neuroleptics need not be withheld from any schizophrenic patients. Other aspects of Crow's hypothesized distinction have indicated possible promising results, but more research is required.