Schizotypy and creativity in visual artists

'Every work of art is an uncommitted crime' Adorno (1951). Cited in Julius (2002). Given the putative relationship between creativity and schizotypy/psychoticism, the current study set out to investigate differences in scores on a range of personality and creativity measures between visual artists and non-artists. Results found that the visual artists group scored higher on measures of positive-schizotypy, disorganized-schizotypy, asocial-schizotypy, neuroticism, openness and divergent thinking (uniqueness) than did the non-artist group and lower on agreeableness. These findings lend support to other studies reporting higher schizotypy scores in artistic and creative cohorts, although provide some of the first evidence of higher unusual experiences and impulsive nonconformity scores on the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) in visual artists. The relationship between creativity and schizotypy is discussed in terms of unusual ideas and a propensity to endorse socially undesirable responses.

Cognitive function and symptoms in adolescents with schizotypal personality disorder

Cognitive deficits have been documented in schizophrenia and spectrum disorders. This study examines cognitive functioning and its relation to symptoms in adolescents with schizotypal personality disorder (SPD). Participants are 89 adolescents recruited for a study of youth at risk for Axis I disorders, especially psychosis. At intake, 34 met criteria for SPD, 38 for another Axis II disorder and/or conduct disorder (Other disorder-OD), and 17 did not currently meet criteria for any DSM-IV disorder (normal control-NC). At initial assessment, cognitive functioning was measured using subtests from the Wechsler Intelligence Scales and Wechsler Memory Scales (WMS), and symptoms were measured using the Structured Interview for Prodromal Symptoms (SIPS). At the time of this report, 50 were readministered the SIPS at 1-year follow-up (T2). The SPD group scored significantly below the NC group on the Arithmetic subtest of the Wechsler Intelligence Scales, but there was only limited evidence of group differences on the WMS. Poorer performance on the Wechsler Intelligence Scales was associated with greater severity of negative and disorganized symptoms. Deficits on the WMS were linked with more severe disorganized symptoms. The findings reported here are consistent with previous reports of limited cognitive deficits in adolescents with SPD, with the most marked deficits in mental arithmetic. The associations between symptoms and cognitive scores parallel those observed in adults with schizophrenia and spectrum disorder, and they are consistent with the notion that negative symptoms are more stable and partially reflect premorbid cognitive functions.

Height, weight and body mass index in early adulthood and risk of schizophrenia

OBJECTIVE

To illuminate the possible associations between height, weight, and body mass index (BMI) during early adulthood and the development of schizophrenia.

METHOD

This prospective study is based on an all-male sample of 3210 individuals from the Copenhagen Perinatal Cohort, comprising individuals born between 1959 and 1961. In 1999, cases of schizophrenia were identified in the Danish Psychiatric Central Register, and the cases were compared with the cohort pool of controls with respect to height, weight, and BMI from draft records. The effect of low BMI was adjusted for parental social status when the cohort members were 1 year old, birth weight, birth length, and maternal pre-pregnancy BMI.

RESULTS

Forty-five cases of schizophrenia had a lower young adult mean body weight and BMI than controls. A significant inverse relationship between BMI and risk of later schizophrenia was found. For each unit increase in BMI, the adjusted odds ratio was 0.81 (95% CI, 0.70-0.93) and the risk of schizophrenia decreased by 19%. Excluding individuals who had been admitted to an in-patient facility before or within 5 years after appearing before the draft board, yielded virtually the same results. No significant differences between cases and controls were observed with respect to adult height.

CONCLUSION

Independent of several possible confounders, an inverse relationship between young adult BMI and risk of later development of schizophrenia was demonstrated in this all-male sample.

The effect of gender in diagnosing early schizophrenia--an experimental case simulation study

BACKGROUND

Studies of diagnostic practice confirm that there is a diagnostic delay in diagnosing women with schizophrenia compared to diagnosing men. The aim of the present study was to investigate the diagnostic practice of Norwegian and Russian psychiatrists when it comes to early psychosis, emphasising gender differences. We wanted to study the association between patient gender as such and diagnostic decision-making among psychiatrists.

MATERIALS AND METHODS

Psychiatrists in Norway and the Archangels region in Russia were invited to participate in a study of diagnostic practice, and received a written case description of a patient with early psychosis symptoms that could be interpreted as schizophrenia. They were, however, not informed that 50% of them received a female case description and 50% a male case description. Apart from the patient being described as "he" or "she" the stories were identical. Effects of patient gender, clinician gender, age and main area of interest were estimated using logistic regression analysis.

RESULTS

A total of 467 psychiatrists answered the questionnaire. We found that schizophrenia diagnosis was given significantly more often to the male case than to the female case. Our finding remained significant after adjustment for country, clinician gender, age and main area of interest, and is unlikely to be explained by known biases.

CONCLUSION

Patient gender in itself affects clinicians' diagnostic practice regarding schizophrenia, as schizophrenia diagnosis is given significantly more often to a male case description than to a female one, the descriptions being otherwise identical.

Validity and reliability of the CAPE: a self-report instrument for the measurement of psychotic experiences in the general population

OBJECTIVE

General population longitudinal cohort studies have demonstrated the prognostic validity of self-reported psychotic experiences, but data on reliability and cross-validation with interview-based measures of these experiences are sparse. This study tested the reliability and validity of the Community Assessment of Psychic Experiences (CAPE42).

METHOD

At baseline, the CAPE42 was used to measure the subclinical psychosis phenotype in a general population sample (n = 765). At follow-up (mean interval: 7.7 months), the Structured Interview for Schizotypy, Revised (SIS-R), the Brief Psychiatric Rating Scale (BPRS), and the CAPE42 were administered (n = 510).

RESULTS

Baseline self-reported dimensions of psychosis were specifically and independently associated with their equivalent interview-based dimension at follow-up (standardized effect sizes of 0.4-0.5) and with their equivalent self-reported measure (standardized effect sizes of 0.6-0.8).

CONCLUSION

The results indicate that self-reported dimensions of psychotic experiences in general population samples appear to be stable, reliable and valid.

The BPQ: a scale for the assessment of borderline personality based on DSM-IV criteria

The aim of the study was to develop a self-report measure that assesses borderline personality traits as defined by DSM-IV criteria, including separate subscales for each criterion. A sample of normal subjects from community colleges in the midwestern region of the United States was used to develop the scale. The psychometric properties of the scale were examined using an additional United States sample and student samples from England and Australia. The scale was compared with existing measures of borderline and schizotypal personality. Evidence for the internal consistency and convergent and divergent validity of the new scale is presented. The results of several analyses of variance comparing males and females in the three national groups are reported. A Principal Components Analysis of the subscales suggested either a single factor or two correlated factors. Oblique rotation yielded a structure that distinguished identity/interpersonal and impulsivity borderline personality traits. It is concluded that the new scale provides a useful tool for clinicians and researchers interested in screening for borderline personality traits in both general and clinical populations. Suggestions for further research are indicated.

Evidence of semantic disorganisation using semantic priming in individuals with high schizotypy

Semantic processing deficits are present in schizophrenia and are particularly evident on semantic priming tasks. Using high schizotypes (psychosis-prone individuals) can overcome some confounds involved in studying actively symptomatic schizophrenics. In the current study, 26 high and 32 low scorers on the O-LIFE schizotypy scale (from a sample of 251 students) were selected for testing. All subjects were administered a lexical-decision semantic priming task where half the stimuli had a short 200 ms stimulus onset asynchrony (SOA, length of time from onset of prime to onset of target) and half the stimuli had a long 750 ms SOA. In addition, half the words were of high frequency and half of a low frequency. There were no group differences in priming for words of different frequencies. Low schizotypes showed greater priming at the 200 ms SOA than at the 750 ms SOA, whilst individuals with high schizotypy showed the opposite pattern. The pattern shown by the low schizotypes replicates earlier work by the authors using other normal control samples; establishing that there is greater priming under conditions of automatic spreading of activation. Furthermore, the data shows there is not an increase in automatic spreading of activation in individuals with high schizotypy. There has been controversy in the schizophrenia literature over whether there is increased priming under automatic conditions. The current study suggests that, when confounds are controlled for, schizophrenia-like symptoms are not related to an increase in automatic spreading of activation.

Over-representation of Maori New Zealanders among adolescents in a schizotypy taxon

BACKGROUND

Minority ethnic and migrant groups are often over-represented among those with schizophrenia.

OBJECTIVES

The aim of this study was to determine whether Maori, the aboriginal minority of New Zealand, are over-represented in a schizotypy taxon derived from a general population sample of adolescents.

METHOD

Secondary school students (n = 387) aged 13 to 17 years completed self-report measures of four schizotypy attributes, magical thinking, hallucinatory tendency, self-referential ideation, and perceptual aberration, and indicated ethnic descent and self-identified ethnic belonging.

RESULTS

Taxometric analyses (maximum covariance, maximum eigenvalue, latent modes) yielded consistent evidence of taxonicity of schizotypy. Participants who were of Maori descent were over-represented in the schizotypy group.

CONCLUSIONS

Ethnicity, or the stress and resilience factors for which ethnicity is a proxy measure, has a measurable impact on psychometric risk for schizophrenia.

Hierarchical relationships between borderline, schizotypal, avoidant and obsessive-compulsive personality disorders

OBJECTIVE

Comorbidity among personality disorders is widely considered problematic. The validity of one proposed solution, diagnostic hierarchies, was investigated in the current study with respect to borderline, schizotypal, avoidant, and obsessive-compulsive personality disorders.

METHOD

One approach used discriminant functions, derived from multiple psycho-social domains, that were used to classify comorbid individuals from the Collaborative Longitudinal Personality Disorder study (CLPS) to explore the possibility of hierarchical precedence of one personality disorder over another. A second approach examined the incremental increase in R(2)-value in predicting functioning and personality provided by each diagnosis over each other diagnosis.

RESULTS

Obsessive-compulsive personality disorder was consistently subordinate to other diagnoses, whereas other indications of hierarchical relationships were domain-specific.

CONCLUSION

Results indicate minimal support for an over-arching hierarchical pattern among studied personality disorders, and suggest the inclusion of all relevant diagnoses in clinical practice.

Effects of repeated amphetamine administration on antisaccade in schizophrenia spectrum personality

Repeated amphetamine administration is used to examine the responsivity of cerebral dopaminergic systems. Schizophrenia spectrum personality (SSP) provides a unique opportunity to study the pathophysiology of schizophrenia because of shared neurobiology without the confounding factors of acute psychosis and psychotropic exposure. Previously we noted that on repeated amphetamine administration, dyskinesia and SSP symptoms were less likely to worsen in SSP than in healthy volunteers. In the current study, we report the effects of repeated amphetamine on antisaccade task performance. Eleven SSP and seven healthy subjects were given placebo once and amphetamine (30 mg) twice, in randomized double-blind fashion at least 1 week apart. Antisaccade eye measurements (error rate and latency) were recorded over 30 trials in each direction. Analysis of error rate showed no significant main effects of the drug. There was a significant group by field by drug interaction effect on the antisaccade latency. The SSP group showed a significant reduction in antisaccade latency for right field targets whereas no significant effects were noted in healthy control subjects. Findings from this preliminary study suggest SSP may be more receptive to the beneficial effects of repeated amphetamine on cognition than healthy controls.

Self-reported mental health difficulties and subsequent risk for schizophrenia in females: a 5-year follow-up cohort study

BACKGROUND

Patients with schizophrenia often report a history of premorbid mild to severe psychological distress. We investigated the association between self-reported mental health difficulties and later psychiatric hospitalization for schizophrenia.

METHODS

13,357 females aged 17, mandatory assessed by the Israeli Draft Board were followed up over 5 years for psychiatric hospitalization by means of the Israeli National Psychiatric Hospitalization Case Registry. Seventeen females, judged healthy at Draft Board assessment, were hospitalized for schizophrenia or schizoaffective disorder over the follow-up period.

RESULTS

There was a significant monotonic association between increasing self-reported mental health difficulties (psychological distress and increasing need for psychological counseling) and prevalence of schizophrenia [odds ratios over four levels: 1.56; 95% CI:1.04 to 2.34; chi2 (1) = 4.62, p = 0.03], after controlling for low IQ, immigration, SES, and presence of psychiatric disorders at age 17. Increasing severity of self-reported mental health difficulties was related to earlier age of first hospitalization [r = -0.48, p = 0.05].

CONCLUSIONS

Increased undifferentiated self-reported mental health difficulties are associated with increased risk of later hospitalization for schizophrenia prior to age 23 in females. This may reflect the prodromal phase of the illness.

[Schizotypal personality disorder--diagnosis and treatment]

Schizotypal personality disorder is relatively common disorder, and is considered to be a mild form of schizophrenia. It is characterized by such "psychotic" symptoms as ideas of reference, odd or magical thinking, perceptual illusions and an inappropriate or flattened affect. In their contact with others, patients show odd expression and behavior. Since, numerous schizotypal symptoms can be treated successfully with atypical antipsychotic medication, the patient should be referred to a psychiatrist or neurologist. The mainstay of psychotherapy consists in crisis management, development of self-awareness of the problem, breaking down social isolation and general unspecific support in coping with daily problems.

Sustained attention deficits in relation to psychometrically identified schizotypy: evaluating a potential endophenotypic marker

Sustained attention deficits have been posited as a potential endophenotypic marker of vulnerability to schizophrenia. Prior studies have indicated that schizophrenia patients, their first-degree relatives, and psychosis-prone individuals, identified on the basis of measures of positive schizotypy, have demonstrated sustained attention deficits. To date, there have been no published reports of sustained attention deficits in individuals with negative schizotypy, as measured by the revised Social Anhedonia Scale. In this study, we examined sustained attention, measured with the CPT-Identical Pairs version, in 160 individuals with elevated scores on the Chapman Perceptual Aberration and/or Magical Ideation Scales, 96 individuals with elevated scales on the Social Anhedonia Scale, and 137 controls. Both psychosis-prone groups performed more poorly than the controls in terms of discrimination ability, as measured by d', though the groups did not differ in terms of either their reaction time or overall response criterion (lnbeta). These results provide evidence that both positive and negative aspects of schizotypy are associated with sustained attention deficits, as measured by the Continuous Performance Test. The findings add to the converging evidence indicating that sustained attention deficits are a potential endophenotypic indicator of a schizophrenia diathesis.

Premorbid childhood ocular alignment abnormalities and adult schizophrenia-spectrum disorder

This study examined the relation between childhood ocular alignment deficits and adult psychiatric outcomes among children at high-risk for schizophrenia and controls. A sample of 265 Danish children was administered a standardized eye exam assessing strabismus and related ocular alignment deficits. All children whose mothers or fathers had a psychiatric diagnosis of schizophrenia comprised the first group (N=90). Children who had at least one parent with a diagnosis other than schizophrenia comprised the first matched control group (N=93). The second control group consisted of children with no parental diagnoses (N=82). In 1992, adult psychiatric outcome data were obtained for 242 of the original subjects. It was found that children who later developed a schizophrenia-spectrum disorder had significantly higher eye exam scale and strabismus scale scores compared to children who developed other non-psychotic psychopathology and children who did not develop a mental illness. The mean rank for children in the high-risk group (offspring of parents with schizophrenia) on the eye scale and the strabismus scale was greater than the mean rank for children in the matched control groups (both offspring of parents with other non-psychotic disorder and no mental illness), although the results failed to reach statistical significance. Results from this study suggest a premorbid relation between ocular deficits and schizophrenia-spectrum disorders in childhood prior to onset of psychopathology in adulthood. Strabismus may serve as a premorbid marker for spectrum disorders and may have implications for the understanding of early aberrant neurological development related to later schizophrenia-spectrum disorders.

The five-factor model in schizotypal personality disorder

Studies of the five-factor model of personality in schizotypal personality disorder (SPD) have produced inconsistent results, particularly with respect to openness. In the present study, the NEO-FFI was used to measure five-factor personality dimensions in 28 community volunteers with SPD and 24 psychiatrically healthy individuals. Standard multivariate statistical analyses were used to evaluate personality differences as a function of diagnosis and gender. Individuals with SPD had significantly higher levels of neuroticism and significantly lower levels of extraversion, agreeableness and conscientiousness than those without SPD. Female, but not male, SPD subjects had significantly higher openness levels than their healthy counterparts, and this gender-specific group difference persisted when SPD symptom severity was statistically controlled. These findings suggest that gender-associated differences in openness may account for prior inconsistent findings regarding this dimension, and they further underscore the importance of examining gender effects in future studies of SPD.

Schizotypal personality disorder or prodromal symptoms of schizophrenia?

Schizotypal personality disorder shares some attenuated phenotypic features with schizophrenia, but represents an independent syndrome. In contrast, prodromal symptoms of schizophrenia represent early warning signs of the impending onset of schizophrenia. Although these constructs are intended to reflect independent syndromes, self-report instruments measuring these constructs assess similar symptoms. It does not appear that existing research has examined the relative discriminant validity of screening instruments for these syndromes. A sample of 998 young adults (68% female; 73% Caucasian), within the age of risk for schizophrenia (ages 18-34; mean 20.4+/-2.2), met validity criteria after completing online versions of the Abbreviated Schizotypal Personality Questionnaire (SPQ-B) and the 24-item Abbreviated Youth Psychosis at Risk Questionnaire (Y-PARQ-B). Based on clinical cut-off scores used in previous research, 5.2% were [only] considered at heightened risk for psychosis (potentially prodromal), 3.4% had [only] schizotypal personality features, and 2.9% met criteria for both constructs (75% of individuals meeting cutoff for one measure did not meet criteria for the other). Males and younger participants scored significantly higher on both measures. The total scores from the SPQ-B and Y-PARQ-B showed a significant positive correlation (r(s)=.66, p<.001, R2=.43); however, 57% of the variance was not shared between the measures. Of the three SPQ-B subscales, Cognitive-Perceptual showed the strongest correlation with Y-PARQ-B. Results suggest that the SPQ-B and Y-PARQ-B have moderate discriminate validity between the overlapping, yet distinct, constructs of schizotypal personality and heightened risk of developing psychosis (potentially prodromal).

Development of a version of the Schizotypy Traits Questionnaire (STA) for screening children

Schizotypy may be seen as both a dimension of normal individual differences and an indicator of the predisposition to schizophrenia and schizophrenia-spectrum disorders. Schizotypal traits have been widely investigated in adults but little research has explored schizotypy in younger samples. The aim of the present study was to examine the factor structure of schizotypal traits in a sample of normal children aged 11 to 15 years-a younger sample than investigated in the few previous studies. Schizotypal traits were assessed with the children's version of the adult Schizotypy Traits Questionnaire (STA). A principal components analysis was carried out on data from 317 subjects and yielded a three-factor solution, similar to several previous studies of adult samples. Factor one was characterised by unusual perceptual experiences, factor two by paranoid ideation/social anxiety, and factor three by magical thinking. The factor structure of the STA of this young sample was comparable with the previous studies of adults. The findings suggest that the children's version of STA is a scale suitable for the measurement of schizotypy in young populations, and that this scale could be useful in clinical assessment of children at risk for psychosis, as well as in research.

Effects of personality disorders on functioning and well-being in major depressive disorder

BACKGROUND

Patients with depressive disorders have limitations in physical and emotional functioning comparable to patients with chronic medical conditions. Personality disorders (PDs) are also known to be associated with functional impairment.

AIMS

To determine the effects of PDs on the functioning and well-being of patients with major depressive disorder (MDD).

METHOD

In the Collaborative Longitudinal Personality Disorders Study, 668 patients who met criteria for schizotypal, borderline, avoidant, or obsessive-compulsive PDs or for MDD and no PD were assessed with semi-structured interviews at baseline, 6, 12, 24, and 36 months. In this study, 151 patients who met criteria for current MDD at the 36-month follow-up were compared on the basis of the presence (n = 118) or absence (n = 33) of persistent PD. Physical and social/emotional functioning and well-being were assessed using the Medical Outcomes Study (MOS) Short-Form Health Survey (SF-36). These results were compared with those of a sample of patients with MDD seen in the mental health specialty sector who were followed in the Medical Outcomes Study.

RESULTS

Patients with MDD and co-occurring PD had significantly more impairment on scales measuring role limitations due to emotional problems, social functioning, and general health perceptions than patients with MDD and no PD. Although patients with MDD and no PD were found to have levels of functioning and well-being that were lower in several domains than those previously reported in depressed patients recruited from mental health settings, patients with MDD and co-occurring PD were found to have much lower levels of functioning in all areas than reported samples.

CONCLUSIONS

Co-occurring PDs contribute significantly to impairment in social and emotional functioning and reduced well-being in patients with MDD.

Replication of dissociation-psychosis link in New Zealand students and inmates

To assess the relationship between dissociative and psychotic experiences, New Zealand university students (N = 119) and prison inmates (N = 42) were administered the Dissociative Experiences Scale (DES) and Symptom Checklist-90-Revised (SCL-90-R). Strong correlations were found between DES scores and the psychoticism and paranoid ideation subscales of the SCL-90-R (students: r = .520, .517, respectively; inmates: r = .637, .649, respectively). While other correlations were also significant (but smaller), these results are consistent with previous studies that have used a range of measures of psychosis or schizotypy with a variety of clinical and nonclinical populations. Such consistent findings in the face of methodological diversity offer strong support for the validity of a link between the concepts of dissociation and psychosis. While this relationship has previously been interpreted indirectly, as dissociative experiences predisposing to psychotic symptoms, we suggest a direct route: that dissociative experiences of various forms may underlie some (or even all) psychotic symptoms.

Short scales for measuring schizotypy

BACKGROUND

This study reports short scales for measuring several dimensions of schizotypy in the normal population based on a large twin sample.

METHODS

The four short scales use items drawn from a longer instrument, the Oxford-Liverpool Inventory of Feelings and Experiences. Using concordance estimates from MZ and DZ pairs, the items were selected both to have a high heritability and to offer broad coverage of each trait domain.

RESULTS

Preliminary descriptive statistics are reported for the short scales and suggest adequate reliability.

CONCLUSIONS

New scales offer a time efficient and reliable method of studying proneness to psychosis in large N designs.

Clinical, cognitive, and social characteristics of a sample of neuroleptic-naive persons with schizotypal personality disorder

INTRODUCTION

Schizotypal personality disorder (SPD) shares with schizophrenia many biological features, yet little is known about the clinical characteristics of persons diagnosed with this disorder. This report describes the clinical, cognitive and socio-occupational characteristics of a community sample of subjects diagnosed with SPD.

METHOD

Sixty-four male and 40 female neuroleptic-naive DSM-IV SPD subjects and 59 male and 51 female comparison subjects were recruited from the community for a total sample of 214 subjects. Demographic and cognitive differences between groups and, within the SPD group, the effect of gender on clinical features, such as the SPD criteria, SAPS, SANS, Schizotypal Personality Questionnaire, and co-morbidity, were examined using ANOVA and Chi-square distributions.

RESULTS

SPD subjects, in contrast to comparison subjects, had significantly lower socio-economic status, poorer social relationships and skills, and lower vocabulary scores. Furthermore, SPD subjects demonstrated more impairment on Vocabulary scores than on Block Design, as measured by the WAIS-R, a pattern not seen in comparison subjects. In the SPD cohort, positive symptoms predominated and nearly half were co-morbid for major depression. With respect to gender, male SPD subjects, compared with female SPD subjects, evinced significantly more negative symptoms, fewer friends, had more odd speech, and were more likely to also suffer from paranoid and narcissistic personality disorders. In contrast to male SPD subjects, female SPD subjects perceived themselves to be more disorganized.

CONCLUSIONS

SPD subjects, similar to schizophrenics, are impaired socially, occupationally, and cognitively, particularly in the area of verbal measures. Moreover, male SPD subjects may be more severely affected than female SPD subjects across multiple domains of functioning.

Longitudinal studies of personality disorders: four lessons from personality psychology

The three longitudinal projects described in this special section of the Journal of Personality Disorders raise a number of intriguing questions concerning the natural history of personality disorders and offer more than their share of surprises. In addition, they underscore several valuable lessons derived from the literature on normal-range personality traits. Drawing in part from the writings of the American trait psychologist Gordon Allport, I describe four such lessons: (1) change and continuity of personality traits and disorders can and do coexist, (2) the covariation among personality traits helps to account for the "comorbidity" among personality disorders, (3) personality traits and disorders influence how individuals interpret life events, and (4) personality traits must be distinguished from behavioral adaptations to these traits. These lessons remind us that the science of personality disorders must be informed by the basic science of personality.

Schizotypy and mixed-handedness revisited

Although some previous studies assert that an association between schizotypy and loss of hand dominance is well established, the prevailing use of student populations, small effect sizes and arbitrariness of handedness classification suggest that this tentative association merits further investigation. The association of schizotypy and loss of hand dominance was examined using four samples. The first comprised 353 randomly selected individuals from the general community, the second comprised 131 screened volunteers participating as control subjects in a family study of schizophrenia, the third included 97 full siblings of schizophrenia patients, and the fourth consisted of 176 schizophrenia patients from the same study. The samples of screened volunteers and nonpsychotic siblings were used to replicate results from the community sample and to test the hypothesis that an increase in genetic liability is related to the association of schizotypal traits and mixed handedness. The results demonstrated that mixed handedness and schizotypy traits were unrelated in the representative sample from the community. This finding was replicated in the sample of screened volunteers, while siblings of schizophrenia patients showed a trend in the direction of the hypothesised relationship. In contrast, there was an expected significant but low in magnitude association between loss of hand dominance and the Schizotypal Personality Questionnaire factor of Cognitive Perceptual Dysfunction in schizophrenia patients.

Increased prevalence of schizophrenia spectrum disorders in relatives of neuroleptic-nonresponsive schizophrenic patients

OBJECTIVE

It is suggested that schizophrenic patients who respond to neuroleptic medication and those who do not might differ with respect to their pathogenesis. In particular, it has been proposed that genetic factors may contribute to treatment response and/or outcome. In order to test this hypothesis, we compared the pattern of familial aggregation of schizophrenia related disorders in schizophrenic patients who are either responders (R) or nonresponders (NR) to typical neuroleptics.

METHOD

R (n=36) or NR (n=35) patients to typical neuroleptics and healthy controls (n=63) were recruited. At least one key informant relative of each proband was interviewed blind as to the status of the proband using the Family Interview for Genetic Studies. Morbid risk for schizophrenia and cluster A personality disorders and family loading score for schizophrenia were examined in first- and second-degree relatives of these probands.

RESULTS

First-degree relatives of NR patients were at a significantly higher risk for schizophrenia (MR=8.84), compared, respectively, to relatives of controls (MR=1.52) or relatives of R patients (MR=2.45). The same pattern was observed in second-degree relatives. Family loading score for schizophrenia in first- and second-degree relatives was significantly higher in NR compared to R patients.

CONCLUSIONS

Schizophrenic patients who do not respond to typical neuroleptics may suffer from a more familial form of schizophrenia compared to patients who are responders.