An analysis of the clinical features of familial schizophrenia

A systematic review of clinical guidelines on choice, dose, and duration of antipsychotics treatment in first- and multi-episode schizophrenia

Clinical guidelines provide evidence-based recommendations to regulate pharmacological treatment of psychotic disorders. However, the quality of evidence, country of origin, and publication dates of such guidelines vary, which leads to discrepancies between recommendations. This systematic review aimed to examine consensus and disparities between clinical recommendations on the choice, dose, and duration of antipsychotic treatment for first- and multi-episode schizophrenia patients. A literature search through The Cochrane Library, Embase, Medline, PsycINFO, PubMed, Scopus, Web of Sciences, and relevant bibliographies revealed 24 guidelines that met the inclusion criteria. The guidelines indicated mostly consistent recommendations regarding the optimal dose range of antipsychotics, while guidance with regards to the choice and duration of treatment remains somewhat controversial. Current trends in guidelines emphasize that there is simply no 'one-size-fits-all' method to manage schizophrenia patients. Further research is needed not only to address discrepancies between guidelines, but also to justify the gap between theory and practice.

Relationship between menarche and psychosis onset in women with first episode of psychosis

AIM

The aim of this study was to explore the relationship between age at menarche and age at first episode of psychosis, as well as clinical severity and outcome, in a population of women with first-episode psychosis.

METHODS

Clinical and socio-demographical data, age at menarche and at first-episode psychosis, parental history of psychosis and cannabis-use habits were obtained from 42 subjects with a first episode of psychosis. Positive and Negative Syndrome Scale, Clinical Global Impression, Global Assessment Function, Disability Assessment Schedule, Wechsler Adult Intelligence Scale and Wechsler Intelligence Scale for Children, European Quality of Life, and Lewis and Murray Obstetric Complication Scales were administered. Statistical analysis was performed by means of zero-order correlations and Mann-Whitney U and Kruskal-Wallis tests using SPSS version 17.0.

RESULTS

We found no significant correlation between age at menarche and age at first-episode psychosis, or with the clinical scores performed. We observed that subjects with earlier age at menarche had more parental history of psychosis.

CONCLUSIONS

Our negative results do not support the theory of a possible protective role of oestrogen, which seems to be more complex than previously thought. We would suggest that further research is needed to investigate developmental influences of sex steroids on the onset of psychosis and potentially therapeutic benefits based upon oestrogen.

Gender difference in age at onset of schizophrenia: a meta-analysis

BACKGROUND

Most studies reporting the gender difference in age at onset of schizophrenia show an earlier onset in males, but vary considerably in their estimates of the difference. This may be due to variations in study design, setting and diagnostic criteria. In particular, several studies conducted in developing countries have found no difference or a reversed effect whereby females have an earlier onset. The aim of the study was to investigate gender differences in age of onset, and the impact of study design and setting on estimates thereof.

METHOD

Study methods were a systematic literature search, meta-analysis and meta-regression.

RESULTS

A total of 46 studies with 29,218 males and 19,402 females fulfilled the inclusion criteria and were entered into a meta-analysis. A random-effects model gave a pooled estimate of the gender difference of 1.07 years (95% confidence interval 0.21-1.93) for age at first admission of schizophrenia, with males having earlier onset. The gender difference in age at onset was not significantly different between developed and developing countries. Studies using diagnostic and statistical manual of mental disorders (DSM) criteria showed a significantly greater gender difference in age at onset than studies using International Classification Of Diseases (ICD) criteria, the latter showing no difference.

CONCLUSIONS

The gender difference in age of onset in schizophrenia is smaller than previously thought, and appears absent in studies using ICD. There is no evidence that the gender difference differs between developed and developing countries.

Family history of psychosis negatively impacts age at onset, negative symptoms, and duration of untreated illness and psychosis in first-episode psychosis patients

Family history (FH) of psychosis has been a focus of investigations attempting to explain the heterogeneity in schizophrenia. Previous studies have demonstrated that FH is associated with earlier age at onset, severity of positive and negative symptoms, and the duration of untreated illness (DUI). The current study examined the impact of FH on the clinical presentation and help-seeking behaviors of a well-characterized, first-episode sample. The present study utilized the Symptom Onset in Schizophrenia (SOS) Inventory, the Positive and Negative Syndrome Scale (PANSS), and structured interviews on FH to examine these relationships in a large (n=152) sample of predominantly African American patients. Results showed that patients with a first-degree FH of psychosis had a younger age at onset of both the prodrome and psychosis, but did not differ in duration of prodromal period. Furthermore, FH and sex interacted to influence severity of negative, but not positive symptoms. Finally, FH interacted with sex to influence both the DUI and DUP in that only males with FH had longer DUI and DUP. The findings have implications for understanding the impact of specific family-related mechanisms on both clinical and help-seeking factors, as well as for informing future family-based intervention efforts.

Concordance between chart review and structured interview assessments of schizophrenic symptoms

BACKGROUND

It is unclear whether direct structured interviews are able to capture the full range of psychopathology in schizophrenia, as is required in diagnostic assessments or clinical ratings. We examined agreement between symptom ratings derived from direct patient interviews and from review of casenotes.

METHODS

The study sample comprised 1021 schizophrenic subjects collected as part of the Irish Case-Control Study of Schizophrenia. Diagnostic interviews used a modified version of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Symptoms were rated by the interviewer. In addition, the Casenote Rating Scale was used to rate symptoms based on medical record information. For each negative and positive symptom, we calculated the Pearson correlation between the interview and the casenote rating. Using the mean of the interview and casenote rating for each symptom, exploratory factor analysis using Varimax rotation was performed.

RESULTS

Three factors were extracted in factor analysis: positive, negative, and Schneiderian symptoms. The highest correlations between interview and casenote ratings were for negative symptoms, in which all symptoms were significantly correlated. Positive and Schneiderian symptoms were significantly correlated with the exception of thought insertion, thought withdrawal, voices speaking in sentences, and somatic hallucinations. Significant correlations were generally moderate (0.2-0.55).

CONCLUSION

Most schizophrenic symptoms, especially negative symptoms, can be assessed by direct interviews as the sole source of information with moderate reliability. However, the presence of some Schneiderian and possibly less prevalent positive symptoms may be difficult to determine without a review of records, which may include longitudinal observations and information from multiple observers.

The impact of a family history of psychosis on age-at-onset and positive and negative symptoms of schizophrenia: a meta-analysis

The results of research on the relation of family history (FH) of psychosis with clinical presentation in schizophrenia have been mixed. To date, there have been no comprehensive reviews that have examined this body of research. The current review quantitatively evaluates research on the relation of FH with two aspects of schizophrenia, age-at-onset and symptom presentation. Studies investigating the influence of a FH on age-at-onset (N=15 studies), age-at-onset and sex (N=12 studies), and/or positive (N=11 studies) and negative symptoms (N=12 studies) in patients with schizophrenia were included in the meta-analyses. Results showed that FH has a small but significant impact on age-at-onset as well as negative symptoms. Of most interest was the finding that sex differences in age-at-onset are not observed in samples with a FH. Furthermore, there was a significant interaction between FH and sex with respect to negative symptoms. The findings of the current review are discussed in light of the diathesis-stress model. Theoretical assumptions and empirical research are reviewed to support the notion that FH influences susceptibility and presentation through similar mechanisms. Implications of the current findings, limitations of the review, and directions for future research are highlighted.

Prediction of symptom remission in schizophrenia during inpatient treatment

OBJECTIVE

Standardized consensus criteria for remission in schizophrenia were recently proposed. The present study applied the symptom-severity component of these criteria to a sample of inpatients in order to determine the rates of remission during inpatient treatment and to explore predictors of remission.

METHOD

A total of 288 inpatients from a multi-centre follow-up programme who fulfilled ICD-10 criteria for schizophrenia were included in the present analyses. PANSS ratings at admission and at discharge from hospitalization were used to examine remission status. Clinical and sociodemographic variables at admission were tested for their ability to predict remission at discharge.

RESULTS

In total, 55% of the sample achieved symptom remission during inpatient treatment; 84% percent showed remission with respect to 'reality distortion', 85% with respect to 'disorganization' and only 65% with respect to 'negative symptoms'. Logistic regression analysis revealed that the global functioning (GAF) in the year before admission, the total score of the Strauss-Carpenter Prognostic Scale and the PANSS negative subscore at admission were predictive for symptom remission. The regression model showed a predictive value of about 70% and explained 36% of the observed variance.

CONCLUSION

The results highlight the impact of negative symptoms for the course and treatment response of schizophrenic illness.

Psychopathological characteristics and treatment response of first episode compared with multiple episode schizophrenic disorders

OBJECTIVE

The aim was to investigate the hypothesis that patients with first episode schizophrenic disorders have a more favorable treatment response than those with multiple episodes.

METHOD

A total of 400 inpatients from an ongoing multi-centre, follow-up program who fulfilled ICD-10 criteria for schizophrenic disorders (F2) were assessed at admission to and discharge from hospital using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

At admission, first episode patients (n = 121) showed higher levels of positive symptoms (PANSS positive subscore) and lower ones of negative symptoms (PANSS negative subscore) than multiple episode patients (n = 279), whereas the global disease severity (PANSS total score) was comparable. Analyses of covariance revealed that treatment response (adjusted symptom levels at discharge) was more favorable in first-episode patients, with respect to both positive and negative symptoms.

CONCLUSION

The results are compatible with the hypothesis that treatment response becomes less favorable during the course of schizophrenic illness. This finding might be associated with progressive neurobiological alterations.

Schizotypal dimensions: an intermediate phenotype associated with the COMT high activity allele

BACKGROUND

Although catechol-O-methyltransferase (COMT) has long been suggested to be implicated in the pathogenesis of schizophrenia, association studies have generated discrepant results concerning the involvement of the COMT gene in schizophrenia. As several studies have suggested that schizotypal traits might be genetically related to schizophrenia, increased statistical power to detect gene effects could be obtained by using dimensional personality traits in unaffected relatives.

METHODS

We tested the hypothesis that the functional Val158Met COMT polymorphism might contribute to the variance of self-reported schizotypal scores in a sample of 106 unaffected subjects, composed of controls (N = 57), first-degree relatives of schizophrenic (N = 27) and of bipolar (N = 22) probands. We also looked for specific associations between COMT polymorphisms and the three dimensions of schizotypy (positive, negative, disorganized) assessed by the Schizotypal Personality Questionnaire (SPQ).

RESULTS

We found that self-reported SPQ scores are related to COMT genotype (P = 0.01), with individuals homozygous for the high activity allele having the highest scores. This association is primarily due to specific associations with the positive (P = 0.001) and negative (P = 0.04) dimensions.

CONCLUSIONS

Our data support the hypothesis that the functional COMT polymorphism could be involved in different psychotic dimensions. This confirms that studying specific schizotypal dimensions can help to identify the genes involved in the pathogenesis of psychosis.

Clinical features of psychotic disorders and polymorphisms in HT2A, DRD2, DRD4, SLC6A3 (DAT1), and BDNF: a family based association study

Schizophrenia is clinically heterogeneous and multidimensional, but it is not known whether this is due to etiological heterogeneity. Previous studies have not consistently reported association between any specific polymorphisms and clinical features of schizophrenia, and have primarily used case-control designs. We tested for the presence of association between clinical features and polymorphisms in the genes for the serotonin 2A receptor (HT2A), dopamine receptor types 2 and 4, dopamine transporter (SLC6A3), and brain-derived neurotrophic factor (BDNF). Two hundred seventy pedigrees were ascertained on the basis of having two or more members with schizophrenia or poor outcome schizoaffective disorder. Diagnoses were made using a structured interview based on the SCID. All patients were rated on the major symptoms of schizophrenia scale (MSSS), integrating clinical and course features throughout the course of illness. Factor analysis revealed positive, negative, and affective symptom factors. The program QTDT was used to implement a family-based test of association for quantitative traits, controlling for age and sex. We found suggestive evidence of association between the His452Tyr polymorphism in HT2A and affective symptoms (P = 0.02), the 172-bp allele of BDNF and negative symptoms (P = 0.04), and the 480-bp allele in SLC6A3 (= DAT1) and negative symptoms (P = 0.04). As total of 19 alleles were tested, we cannot rule out false positives. However, given prior evidence of involvement of the proteins encoded by these genes in psychopathology, our results suggest that more attention should be focused on the impact of these alleles on clinical features of schizophrenia.

How many and which are the psychopathological dimensions in schizophrenia? Issues influencing their ascertainment

During the last two decades, much effort has been made to precisely characterize the symptom dimensions of schizophrenia. A number of dimensional models have been proposed, the most popular of which has been a three-dimensional model consisting of psychotic, negative and disorganizational symptoms. This model, however, has been criticized as too simplistic, and more complex models have been proposed, although to date there has been no consensus as to the number and nature of dimensions necessary to account for the whole range of schizophrenic symptoms. In the present paper, the authors review the main methodological issues which have led to the current confusion about the number of dimensions underlying schizophrenic psychopathology. Among the main issues influencing the delimitation of dimensions are: statistical procedures for determining the number of factors, phase of the illness, level of analysis of symptoms (i.e., symptoms or groups of symptoms), and measurement instrument used. Studies analyzing either a broad range of symptoms or particular symptoms at a finer level have produced a rather complex picture of schizophrenic dimensions. There is evidence supporting the existence of eight major dimensions of psychopathology: psychosis, disorganization, negative, mania, depression, excitement, catatonia and lack of insight. The dimensional structure of symptoms becomes even more complex if one considers that these big dimensions can be further divided into more elementary components. A hierarchical approach for organizing the complex dimensional structure of schizophrenic symptoms is proposed.

Familiality of symptom dimensions in schizophrenia

The division of schizophrenic symptoms into three core dimensions - psychomotor poverty, reality distortion, and disorganisation - is well established. When factor analytic studies have included affective symptoms they have identified two additional dimensions - manic and depressive. Whether these five dimensions represent underlying psychopathology of a genetic or environmental aetiology remains unclear. The aims of this study were to perform factor analysis of symptoms in a group of familial schizophrenic patients and to investigate the familiality of the symptom dimensions identified, and their relationship to clinical characteristics. Symptoms were recorded, using the Operational Criteria Checklist for Psychotic Illness, for 155 Caucasian subjects with an RDC diagnosis of schizophrenia, schizoaffective disorder, or psychosis of unknown origin, from 61 families multiply affected with schizophrenia. Factor analysis indicated five symptom dimensions: depressive, manic, reality distortion, disorganisation, and psychomotor poverty. The psychomotor poverty, disorganisation, and manic dimensions were shown to be familial. Psychomotor poverty, disorganisation, and reality distortion were all associated with deterioration from premorbid functioning and chronic course of the disorder. In addition, psychomotor poverty was significantly related to poor premorbid functioning, as well as to single marital status and unemployment at onset. Disorganisation was significantly related to single marital status and unemployment at onset. The familiality of the psychomotor poverty, disorganisation, and manic dimensions supports their use in the delineation of homogeneous subsets for genetic studies.

Main risk factors for schizophrenia: increased familial loading and pre- and peri-natal complications antagonize the protective effect of oestrogen in women

Women fall ill with schizophrenia 3 to 4 years later than men. The neurobiological mechanism, explaining the delay of onset in women until menopause, is presumably due to a sensitivity reducing effect of oestrogen on central d(2) receptors, as we have previously shown in animal experiments and in a controlled clinical study. The gender difference in age at onset seems to disappear in familial cases with schizophrenia, but it increases to highly significant values of 5 years or more in isolated cases according to a recent study by Albus and Maier (Schizophrenia Research 18:51-57, 1995). We tried to replicate these findings and to test the hypothesis of a functional antagonism between genetic predisposition to illness and the protective effect of oestrogen in a population-based sample of 232 first illness episodes of schizophrenia. In women with at least one first-degree relative suffering from schizophrenia, age at onset defined by first psychotic symptom was significantly reduced by several years and the difference with men disappeared. In sporadic female cases (no mental disorder in first-degree relatives) the age at onset was slightly increased compared with the total sample, which was in accordance with our hypothesis. In men with familial schizophrenia, but without a protective agent like oestrogen, the age at onset was only slightly and non-significantly reduced compared with the total group and with sporadic cases. This was in line with Albus and Maier and with our hypothesis that only the protective effect of oestrogen could be antagonized by a strong genetic disposition. The second main risk factor for schizophrenia is pre- and peri-natal complications. We compared men and women from our sample of first illness episodes with a history of pre- and peri-natal complications with those without a history of obstetric complications. In women the age at first psychotic symptom was markedly reduced, but due to small case numbers not significantly, compared with women without the risk factor and with the total group. Again, schizophrenic men with a history of pre- and peri-natal complications showed only a small, non-significant reduction of age at onset compared with the total and the group without the risk factor. Therefore, we concluded that the degree of genetically determined vulnerability and, presumably to a slightly lesser extent, the degree of pre- and peri-natal brain injury antagonizes the onset delaying effect of oestrogen in schizophrenia.

[Lack of gender effect on familial schizophrenia. A Brazilian study]

Epidemiological studies on schizophrenia have showed different age at onset between gender, in which male schizophrenics present symptoms earlier than females. However this gender effect is not observed within familial schizophrenia. The present study investigates the age at onset in 31 RDC-schizophrenics from 13 Brazilian families. No differences in age at onset were found between gender, confirming previous studies in other populations. This result may indicate genetic influences on age at onset in a subgroup of patients affected by schizophrenia and can be explored by molecular genetic studies.

Age at onset and outcome in schizophrenia are related to the degree of familial loading

BACKGROUND

Recent research suggests that high familial loading is associated with early onset of schizophrenia. Results concerning outcome have been controversial.

METHOD

We assessed the relationship between familial loading, age at onset and outcome in all Finnish patients with schizophrenia born between 1950 and 1969. Patients and their first-degree relatives were identified using nationwide registers. Familial loading scores were calculated for schizophrenia and for combined psychotic disorders, and patients were accordingly classified into three groups: high (n = 761), intermediate (n = 14,247), and low familial loading (n = 725). Linear mixed models and the Cox proportional hazard model were used in the analyses.

RESULTS

Onset was earliest, hospitalisation longest and risk of retirement in receipt of a disability pension highest in the group with high familial loading, with opposite extremes found in the group with low familial loading.

CONCLUSIONS

High familial loading for schizophrenia is associated with early onset and poor outcome of schizophrenia.

Familial associations of subsyndromes of psychosis in affected sibling pairs with schizophrenia and schizoaffective disorder

Attempts to describe the clinical heterogeneity of schizophrenia have consisted of categorical subtyping and a dimensional approach using factor analysis. The latter has yielded three dimensions or subsyndromes: positive, negative and disorganisation. The aim of this study is to explore to what degree these subsyndromes are correlated within 114 sibling pairs (185 individuals) with DSM-III-R schizophrenia or schizo-affective disorder who were assessed for the lifetime presence or absence of the positive, negative, affective and disorganisation subsyndromes. Ratings were based on the core symptoms of each subsyndrome using a modified Krawieka scale. First rank symptoms were also included in the analysis. Coincidence was assessed by application of the binomial theorem to the frequency of occurrence of subsyndromes in this set of siblings. The disorganisation subsyndrome was shared above chance expectation (chi2=9.15, P < 0.01 for all sibling pairs). The significant results for the disorganisation subsyndrome suggest that it may be a suitable phenotypic marker for genetic linkage studies.

Factor structure and clinical validity of competing models of positive symptoms in schizophrenia

BACKGROUND

The factor structure of four competing models of positive symptoms and their clinical validity was studied in a sample of 253 schizophrenia inpatients.

METHODS

The following models were tested using confirmatory factor analysis: a one-dimension severity model, a two-dimension model comprising a psychosis factor and a disorganization factor, a four-dimension model based on the Scale for the Assessment of Positive Symptoms (SAPS) structure in subscales, and a five-dimension model derived from the previous one by further differentiating Schneiderian delusions from non-Schneiderian ones.

RESULTS

More complex multifactorial models fit the data better than simpler models. The five-dimension model was the best adjusted (goodness of fit index = .844, nonnormed fit index = .812, normed fit index = .728). Whereas the one-dimension model did not display significant association with the clinical variables, multidimensional models were related to age at onset and illness severity. The two-dimension model captured well the clinical correlates of the more complex models.

CONCLUSION

None of the tested models showed good fit to the data. The one-dimension model displayed both poor factor validity and poor external validity; therefore, research relying on the SAPS total score may reach misleading conclusions.

Lack of gender differences in familial schizophrenia

Objective:Gender appears to have a significant impact on the prevalence, age at onset, symptoms and outcome of schizophrenia. This study examines gender effects in a population of familial schizophrenic patients in Ireland.

Method:Families with two or more siblings suffering from schizophrenia, as defined by DSM-III-R were ascertained in Ireland. The final sample comprised 169 siblings from 80 families. Siblings were interviewed using the Structured Clinical Interview for DSM-III-R (SCID), the Scale for the Assessment of Negative Symptoms (SANS) and the Strauss-Carpenter Levels of Functioning Scale. The difference between males and females for various clinical features were calculated.

Result:There was a marked excess of affected males (65% male and 35% female). When the excess of male subjects was taken into account there was no significant excess of same-sex as compared to opposite-sex pairs. There were no significant difference between males and females for age at onset, age at first admission, symptoms or level of outcome.

Conclusion:The excess of males and the lack of gender differences for clinical features found in this study may, in part, be due to the narrow diagnostic criteria used. Alternatively, at least some of these findings may be specific to this Irish sample. Further research is a need to see if these findings can be replicated in other countries.

Factor structure of symptoms in functional psychoses

Global ratings from the Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms were subjected to principal-component analysis (PCA) in 80 schizophrenia patients, 76 patients with schizophreniform disorder, 80 patients with schizoaffective and mood disorders, and 78 patients with delusional, brief reactive, and atypical psychoses. The resulting factors were correlated with depressive, manic, and catatonic syndromes, and subjected to a multivariate analysis of variance across DSM-III-R diagnoses. PCAs revealed that psychosis, disorganization, and negative factors were also present in each of the nonschizophrenic groups. The disorganization factor tended to be related to the manic syndrome, and the negative factor to depressive and catatonic syndromes. Overall, the three factors had little diagnostic relevance in functional psychoses, although the negative factor was relatively more characteristic of schizophrenia. The data suggest that positive, negative, and disorganization factors are not specific to schizophrenia; this is consistent with a dimensional view of psychopathology in functional psychoses.

Factor-derived subsyndromes of schizophrenia and familial morbid risks

Factor analysis was performed on OPCRIT checklist ratings from 66 patients with RDC schizophrenia. Eight substantive factors were found, characterised respectively by: positive formal thought disorder; first rank delusions; first rank hallucinations; inappropriate affect/bizarre behaviour; negative symptoms; grandiose/bizarre delusions; delusions of influence/persecution; and other hallucinations. A history of schizophrenia and other non-affective psychoses was ascertained in the probands' first-degree relatives using a family history approach. Illness in relatives was best predicted by probands' scores on subsyndromes derived from the inappropriate affect/bizarre behaviour and positive formal thought disorder factors.

Factor analysis of schizophrenic symptoms using the OPCRIT checklist

Factor analysis was performed on OPCRIT checklist psychotic symptoms rated on 102 patients with DSM-III-R schizophrenia. An initial three-factor solution produced positive, negative, and disorganisation factors. However, application of the scree test suggested five substantive factors, with the positive factor dividing into three factors characterised, respectively, by paranoid symptoms, first rank delusions and first rank hallucinations.

Expanded CAG/CTG repeats in schizophrenia. A study of clinical correlates

BACKGROUND

Schizophrenia is associated with expanded CAG/CTG trinucleotide repeats. We wished to determine whether the presence of such expansions correlated with specific subsyndromes or other clinical features of schizophrenia.

METHOD

Seventy patients from England and Wales and 44 patients from Portugal with a DSM-III-R diagnosis of schizophrenia were rated on the OPCRIT checklist. Patient's maximum CAG/CTG repeat length was measured using repeat expansion detection (RED). Significant differences were sought for repeat lengths in subjects categorised according to dimensional and categorical schizophrenia subsyndromes, affective episodes, individual symptoms, and a range of demographic variables.

RESULTS

Maximum CAG/CTG repeat length did not differ significantly for any of the clinical or demographic variables studied.

CONCLUSION

There are no subsyndromes or other clinical features of schizophrenia associated with CAG/CTG repeat expansion. Therefore, the identification of the gene(s) that contain expanded CAG/CTG repeats and which are associated with schizophrenia is unlikely to be facilitated at present by using any subsyndromes of schizophrenia as phenotypes.

Age of onset in familial and sporadic schizophrenia

We have studied the gender and family history differences with regard to age of onset of schizophrenia. These differences have often been viewed as an important clue to the aetiology of the illness. Patients from three centres in Europe and Canada were included in the study. A sample of 1089 subjects was categorized according to the subject's sex, family history of schizophrenia, and the centre. The principal statistical method was analysis of variance. Patients with no family history of schizophrenia had a consistently higher average age of onset. This effect was seen in both male and female subjects across all three groups. These results support the relationship between familial risk and early onset, but no interaction of gender and family history was found.

Eye movements and psychopathology in schizophrenia and bipolar disorder

The aim of this study was to examine multivariate patterns of relationships between oculomotor performance, psychopathology, and neuropsychology. Performance on smooth pursuit and saccadic eye movement tasks was assessed in three DSM-III-R diagnosis-based groups of subjects; normal (N = 55), schizophrenic (N = 29), and bipolar disorder (N = 26) and analyzed in relation to age, gender, scale for the Assessment of Negative Symptoms, Scale for the Assessment of Positive Symptoms, and Brief Psychiatric Rating Scale scores, Shipley intelligence quotient, and Wisconsin Card Sorting Test Performance. The greatest difference was a higher proportion of errors in the antisaccade task in the schizophrenic and bipolar groups, which was related to worse Wisconsin Card Sorting Test performance and was not accounted for by gender, age, education, or intelligence quotient. A significant gender and bipolar interaction showed bipolar women to have worse antisaccade performance. Abnormal smooth pursuit was more specific to schizophrenia. Antisaccade task and sine wave root-mean-square error were correlated in bipolar but not schizophrenic subjects. Scale for the Assessment of Negative Symptoms and Scale for the Assessment of Positive Symptoms scores had independent associations with the antisaccade task. Faster reaction times in the schizophrenic group to antisaccade errors were observed, suggesting an abnormality in visual attention processing and perhaps sensory gating functions. These results confirm abnormal smooth pursuit in schizophrenia and suggests that impairments in saccadic function are less specific to diagnostic group. Oculomotor performance and psychopathology seem related in complex ways to age, gender, intelligence quotient, and executive neuropsychological and possibly visual attention functions.

Clinical similarities in siblings with schizophrenia

Three symptom groups, identified by factor analysis of schizophrenic symptoms, together with other clinical variables, were compared among 80 sibships (169 individuals) containing two or more members affected with schizophrenia. The three factors, which were labelled negative symptom disorganization, and reality distortion, all showed a moderate but significant degree of correlation between siblings. Age at onset was also significantly correlated. Such a familial pattern of clinical heterogeneity suggests underlying common familial aetiologies that influence the clinical form of the disorder. Whether these are genetic or environmental requires further investigation. This finding confers some external validation on the three factor model. It may be feasible to develop familial symptom patterns as the basis for an a priori approach to linkage heterogeneity.