MMPI variables predictive of schizophrenia in the Copenhagen High-Risk Project: a 25-year follow-up

The stress-vulnerability model on the path to schizophrenia: Interaction between BDNF methylation and schizotypy on the resting-state brain network

The interplay between schizophrenia liability and environmental influences has been considered to be responsible for the development of schizophrenia. Recent neuroimaging studies have linked aberrant functional connectivity (FC) between the default-mode network (DMN) and the frontoparietal network (FPN) in the resting-state to the underlying neural mechanism of schizophrenia. By using schizotypy as the proxy for genetic-based liability to schizophrenia and methylation of brain-derived neurotrophic factor (BDNF) to represent environmental exposure, this study investigated the impact of the interaction between vulnerability and the environment on the neurobiological substrates of schizophrenia. Participants in this study included 101 healthy adults (HC) and 46 individuals with ultra-high risk for psychosis (UHR). All participants were tested at resting-state by functional magnetic resonance imaging, and group-independent component analysis was used to identify the DMN and the FPN. The Perceptual Aberration Scale (PAS) was used to evaluate the schizotypy level. The methylation status of BDNF was measured by pyrosequencing. For moderation analysis, the final sample consisted of 83 HC and 32 UHR individuals. UHR individuals showed reduced DMN-FPN network FC compared to healthy controls. PAS scores significantly moderated the relationship between the percentage of BDNF methylation and DMN-FPN network FC. The strength of the positive relationship between BDNF methylation and the network FC was reduced when the schizotypy level increased. These findings support the moderating role of schizotypy on the neurobiological mechanism of schizophrenia in conjunction with epigenetic changes.

Development and validation of a scale of self-alienation-related attributes for the early diagnosis of schizophrenia

BACKGROUND

The onset of schizophrenia is often preceded by a prodromal phase. However, it is difficult to predict the future transition to schizophrenia from the prodromal symptoms. Based on the diagnostic significance of Schneider's first rank symptoms (FRS), especially those representing "ego disorders (Ichstörungen)", we developed a scale of self-alienation-related attributes (Self-A) to assess the psychological characteristics associated with ego disorders for the early diagnosis of schizophrenia.

METHODS

In total, 153 schizophrenia (Sz) patients, 83 at-risk mental state (ARMS) subjects, and 154 healthy control (HC) subjects participated in this study. The Self-A scale was constructed by items from the Minnesota Multiphasic Personality Inventory (MMPI) based on the differences between schizophrenia patients with and without FRS representing ego-disorders designated as "self-alienation symptoms". The Self-A scale was tested for its reliability and validity in a different sample of schizophrenia patients, and was then applied to different cohorts including first-episode schizophrenia (FES) patients, ARMS individuals, and HC subjects.

RESULTS

The Self-A consisting of 27 items exhibited good internal consistency reliability. The validity was well demonstrated by the high correlation of the Self-A scores with the self-alienation symptom scores. The ARMS and FES groups had higher Self-A scores than the HC group. The Self-A score in the ARMS individuals who later developed schizophrenia was higher than that in the ARMS subjects who did not, and was comparable with that in the FES group.

CONCLUSIONS

This study suggests that the newly developed Self-A scale assessing the self-alienation-related attributes can improve the early diagnosis of schizophrenia.

Schizophrenia: A Survey of Artificial Intelligence Techniques Applied to Detection and Classification

Artificial Intelligence in healthcare employs machine learning algorithms to emulate human cognition in the analysis of complicated or large sets of data. Specifically, artificial intelligence taps on the ability of computer algorithms and software with allowable thresholds to make deterministic approximate conclusions. In comparison to traditional technologies in healthcare, artificial intelligence enhances the process of data analysis without the need for human input, producing nearly equally reliable, well defined output. Schizophrenia is a chronic mental health condition that affects millions worldwide, with impairment in thinking and behaviour that may be significantly disabling to daily living. Multiple artificial intelligence and machine learning algorithms have been utilized to analyze the different components of schizophrenia, such as in prediction of disease, and assessment of current prevention methods. These are carried out in hope of assisting with diagnosis and provision of viable options for individuals affected. In this paper, we review the progress of the use of artificial intelligence in schizophrenia.

The influence of temperament and character on functioning and aspects of psychological health among people with schizophrenia

Research findings that link personality factors to functioning and symptoms in schizophrenia are inconsistent, and further studies are needed within the area. The purpose of this study was to investigate how personality, as measured by the Temperament and Character Inventory (TCI), was related to demographic factors, subtypes of diagnoses, level of functioning, and aspects of psychological health, including sense of coherence, perceived control, and self-esteem, among people with schizophrenia. Subjects were 104 individuals, aged 20–55 years, in psychiatric outpatient care. The results indicated that personality was not related to subtypes of diagnoses or demographic characteristics of the respondents, but to level of functioning and all aspects of psychological health. Especially self-directedness distinguished three groups of functioning and was highly correlated with the different aspects of psychological health. The article discusses how knowledge of schizophrenic patients’ personality structure might be used for tailoring psychiatric treatments.

Differentiation of adoptees at high versus low genetic risk for schizophrenia by adjusted MMPI indices

The aim of this study was to find potential signs of genetic vulnerability to schizophrenia. The differences between adoptees at high genetic risk for schizophrenia (their biological mother had a schizophrenia spectrum disorder) and control adoptees of non-schizophrenia spectrum biological mothers were assessed. The comparisons between these groups were based on the Minnesota Multiphasic Personality Inventory (MMPI) test's subscale scores adjusted by gender, age at MMPI assessment, age at placement into the adoptive family and social class. The subjects were a subsamples of a total of 182 tested adoptees and 136 mentally healthy adoptees in the Finnish Adoptive Family Study. The high-risk group was found to be distinguishable from the low-risk group based on deviant scores on the Hostility, Hypomania and Lie scales. These scales may measure genetic vulnerability and also possibly be indicative of psychometric deviance predicting future onset of schizophrenia.

Identifying non-affective psychosis in first admission patients: MMPI-2, structured diagnostic interview, and consensus lifetime best estimate

PURPOSE

We aimed to evaluate the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) as a potential means of improving on the SCID's diagnostic efficacy.

METHODS

76 first-admission patients were assigned DSM-IV consensus diagnoses by two experienced psychiatrists using all available information, then dichotomized into non-affective psychosis and other mental illness groups. The patients were also given the SCID and the MMPI-2. The diagnostic performance of the MMPI-2 was compared to that of the SCID to assess both diagnostic accuracy and incremental validity.

RESULTS

MMPI-2 scales 8 (Schizophrenia) and BIZ (Bizarre Mentations) correctly identified 58% and 56% respectively of non-affective psychotic patients. The Goldberg Index had an overall correct classification rate of 70%, but only identified 49% of the psychosis group. The SCID had a correct classification rate of 66% but correctly identified only 25% of the non-affective psychosis patients. Three MMPI-2 scales combined with the SCID resulted in an overall correct classification rate of 73%, and identification of 66% of the non-affective psychosis patients.

CONCLUSION

The results suggest that the MMPI-2 may identify early psychosis at least as well as the SCID. Furthermore, using a combination of the MMPI-2 and the SCID shows incremental validity over using the SCID alone.

At-risk studies and clinical antecedents of psychosis, bipolar disorder and depression: a scoping review in the context of clinical staging

Identifying young people at risk of developing serious mental illness and identifying predictors of onset of illness has been a focus of psychiatric prediction research, particularly in the field of psychosis. Work in this area has facilitated the adoption of the clinical staging model of early clinical phenotypes, ranging from at-risk mental states to chronic and severe mental illness. It has been a topic of debate if these staging models should be conceptualised as disorder-specific or transdiagnostic. In order to inform this debate and facilitate cross-diagnostic discourse, the present scoping review provides a broad overview of the body of literature of (a) longitudinal at-risk approaches and (b) identified antecedents of (homotypic) illness progression across three major mental disorders [psychosis, bipolar disorder (BD) and depression], and places these in the context of clinical staging. Stage 0 at-risk conceptualisations (i.e. familial high-risk approaches) were identified in all three disorders. However, formalised stage 1b conceptualisations (i.e. ultra-high-risk approaches) were only present in psychosis and marginally in BD. The presence of non-specific and overlapping antecedents in the three disorders may support a general staging model, at least in the early stages of severe psychotic or mood disorders.

Heritability and Familiality of MMPI Personality Dimensions in the Korean Families with Schizophrenia

OBJECTIVE

Categorical syndrome such as schizophrenia could be the complex of many continuous mental structure phenotypes including several personality development/degeneration dimensions. This is the study to search heritability and familiality of MMPI personality dimensions in the Korean schizophrenic LD (Linkage Disequilibrium) families.

METHODS

We have recruited 204 probands (with schizophrenia) with their parents and siblings whenever possible. We have used MMPI questionnaires for measuring personality and symptomatic dimensions. Heritabilities of personality dimensions in total 543 family members were estimated using Sequential Oligogenic Linkage Analysis Routines (SOLAR). Personality dimensions in total family members were compared with those in 307 healthy unrelated controls for measuring the familialities using ANOVA analysis.

RESULTS

Seven of the 10 MMPI variables were significantly heritable and were included in the subsequent analyses. The three groups (control, unaffected 1st degree relative, case) were found to be significantly different with the expected order of average group scores for all heritable dimensions.

CONCLUSION

Our results show that the aberrations in several personality dimensions could form the complexity of schizophrenic syndrome as a result of genetic-environment coactions or interactions in spite of some limitations (recruited family, phenotyping).

Maladaptive personality traits in patients identified at lower-risk and higher-risk for psychosis

The 'at-risk' state for psychosis is a high-risk paradigm that examines factors that contribute to conversion to a first episode of psychosis. Although a multitude of contributing factors have been identified in one's susceptibility to conversion to psychosis, dimensional pathological personality traits have not been examined in 'at-risk' populations. In this study we examine lower- versus higher-risk for psychosis using traits from the DSM-5 Alternative Dimensional Model of Personality Disorders (AMPD) to investigate which AMPD personality traits distinguish those 'at-risk' patients at relatively lower-risk for conversion to psychosis versus those at higher-risk. Remitted schizophrenic patients served as the comparison group. MANOVA analyses revealed significant group differences on the PID-5, with the higher-risk patients scoring higher on two of the five AMPD trait domains - Negative Affectivity and Detachment - compared to lower-risk patients. Maladaptive personality traits from the AMPD may serve as potential risk factor for conversion to psychosis.

The Relationship Between the Personality Inventory for the DSM-5 (PID-5) and the Psychotic Disorder in a Clinical Sample

Recent studies have successfully investigated the validity of the DSM-5 Alternative Model for Personality Disorders. In a final sample of 174 psychiatric patients, the present study examined the relationship between the Personality Inventory for the DSM-5 (PID-5) and syndromal psychosis. Results showed that patients diagnosed with versus without a psychotic disorder significantly differed on all PID-5 domains except Antagonism. Discriminant function analysis indicated that lower Detachment, lower Negative Affect, lower Disinhibition, and higher Psychoticism best discriminated patients with a psychotic disorder from patients with other psychiatric conditions. Subsequent stepwise discriminant analysis on all facet scales of the contributing PID-5 domains revealed that higher Unusual Beliefs, lower Depressivity, and lower Distractibility contributed the most to this differentiation. PID-5 Psychoticism scores showed moderate correlations with current psychotic symptoms and were not influenced by dose of antipsychotic medication. Our results support the ability of the PID-5 to discriminate between patients with and without psychotic disorder.

Offspring of Parents with Schizophrenia: A Systematic Review of Developmental Features Across Childhood

A significant body of longitudinal research has followed the offspring of parents with schizophrenia. This article presents a systematic review of 46 separate papers presenting the results of 18 longitudinal studies that have followed children who are at familial high risk of developing psychotic disorders. The studies suggest that these children do show distinct developmental patterns characterized by higher rates of obstetric complication, neurodevelopmental features such as motor and cognitive deficits, and distinctive social behavior. This review summarizes those findings according to child developmental stages. Twelve of the studies followed offspring into adulthood and examined psychiatric diagnoses. From 15% to 40% of children at familial high risk developed psychotic disorders in adulthood. Many also received other psychiatric diagnoses such as mood or anxiety disorders. This combination of results suggests that offspring of parents with schizophrenia are at high risk not just for schizophrenia but, more broadly, for poor developmental and general mental health outcomes. The clinical implications of the findings are discussed, as are new prognostic strategies and potential programs for selective prevention.

Premorbid self-disorders and lifetime diagnosis in the schizophrenia spectrum: a prospective high-risk study

AIM

The notion of a disordered self as a core disturbance of schizophrenia was proposed in many foundational texts. Recent studies, spurred by the development of the Examination of Anomalous Self-Experience (EASE), seem to indicate that self-disorders are a specific manifestation of schizophrenia vulnerability. Follow-up studies of help-seeking, prodromal and first-admission patients have demonstrated the utility of self-disorders for predicting later schizophrenia-spectrum disturbance. We wished to extend these findings by gauging the predictive value of self-disorders in a premorbid, non-clinical population at high risk for schizophrenia.

METHODS

Children from the Copenhagen High-Risk Project with high-genetic risk for schizophrenia (N = 212) were assessed premorbidly (average age = 15), and diagnostically re-evaluated after 10 and 25 years. Since the EASE was not available at the time of premorbid assessment, we hypothesized that a proxy scale drawn from the Minnesota Multiphasic Personality Inventory (MMPI) could distinguish those who later developed a schizophrenia-spectrum disorder (N = 68) from those who remained healthy (N = 64). The Self-Disorder Scale comprised 32 items whose content suggested an aspect of self-disorder as measured by the EASE.

RESULTS

Premorbid Self-Disorder Scale scores significantly predicted lifetime schizophrenia-spectrum diagnosis in the high-risk cohort. Although there was considerable item overlap between the new scale and an existing MMPI scale (psychoticism), the overlap did not account for the Self-Disorder Scale's predictive efficacy.

CONCLUSION

The results support the notion of self-disorders as a core vulnerability feature in schizophrenia, detectable premorbidly in those developing later schizophrenia-spectrum disorders.

Developing psychosis and its risk states through the lens of schizotypy

Starting from the early descriptions of Kraepelin and Bleuler, the construct of schizotypy was developed from observations of aberrations in nonpsychotic family members of schizophrenia patients. In contemporary diagnostic manuals, the positive symptoms of schizotypal personality disorder were included in the ultra high-risk (UHR) criteria 20 years ago, and nowadays are broadly employed in clinical early detection of psychosis. The schizotypy construct, now dissociated from strict familial risk, also informed research on the liability to develop any psychotic disorder, and in particular schizophrenia-spectrum disorders, even outside clinical settings. Against the historical background of schizotypy it is surprising that evidence from longitudinal studies linking schizotypy, UHR, and conversion to psychosis has only recently emerged; and it still remains unclear how schizotypy may be positioned in high-risk research. Following a comprehensive literature search, we review 18 prospective studies on 15 samples examining the evidence for a link between trait schizotypy and conversion to psychosis in 4 different types of samples: general population, clinical risk samples according to UHR and/or basic symptom criteria, genetic (familial) risk, and clinical samples at-risk for a nonpsychotic schizophrenia-spectrum diagnosis. These prospective studies underline the value of schizotypy in high-risk research, but also point to the lack of evidence needed to better define the position of the construct of schizotypy within a developmental psychopathology perspective of emerging psychosis and schizophrenia-spectrum disorders.

Using the MMPI-2-RF to discriminate psychometrically identified schizotypic college students from a matched comparison sample

This study investigates the extent to which the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) profiles of 52 individuals making up a psychometrically identified schizotypes (SZT) sample could be successfully discriminated from the protocols of 52 individuals in a matched comparison (MC) sample. Replication analyses were performed with an additional 53 pairs of SZT and MC participants. Results showed significant differences in mean T-score values between these 2 groups across a variety of MMPI-2-RF scales. Results from discriminant function analyses indicate that schizotypy can be predicted effectively using 4 MMPI-2-RF scales and that this method of classification held up on replication. Additional results demonstrated that these MMPI-2-RF scales nominally outperformed MMPI-2 scales suggested by previous research as being indicative of schizophrenia liability. Directions for future research with the MMPI-2-RF are suggested.

Stability in MMPI among adoptees with high and low genetic risk for schizophrenia and with low Communication Deviance of their adoptive parents

Stability has been considered an important aspect of vulnerability to schizophrenia. The temporal stability of the scales in the Minnesota Multiphasic Personality Inventory (MMPI) was examined, using adoptees from the Finnish Adoptive Family Study of Schizophrenia. Adoptees who were high-risk (HR) offspring of biological mothers having a schizophrenia spectrum disorder (n=28) and low-risk (LR) controls (n=46) were evaluated using 15 MMPI scales at the initial assessment (HR, mean age 24 years; LR, mean age 23 years) and at the follow-up assessment after a mean interval of 11 years. Stability of the MMPI scales was also assessed in the groups of adoptees, assigned according to the adoptive parents'(n=44) communication style using Communication Deviance (CD) scale as an environmental factor. Initial Lie, Frequency, Correction, Psychopathic Deviate, Schizophrenia, Manifest Hostility, Hypomania, Phobias, Psychoticism, Religious Fundamentalism, Social Maladjustment, Paranoid Schizophrenia, Golden-Meehl Indicators, Schizophrenia Proneness and 8-6 scale scores significantly predicted the MMPI scores at the follow-up assessment indicating stability in the characteristics of thinking, affective expression, social relatedness and volition. Low CD in the family had an effect on the stabilization of personality traits such as social withdrawal and restricted affectivity assessed by Correction and Hostility.

Psychosis prediction and clinical utility in familial high-risk studies: selective review, synthesis, and implications for early detection and intervention

AIM

Accurate prediction of which high-risk individuals will go on to develop psychosis would assist early intervention and prevention paradigms. We sought to review investigations of prospective psychosis prediction based on markers and variables examined in longitudinal familial high-risk (FHR) studies.

METHODS

We performed literature searches in MedLine, PubMed and PsycINFO for articles assessing performance characteristics of predictive clinical tests in FHR studies of psychosis. Studies were included if they reported on one or more predictive variables in subjects at FHR for psychosis. We complemented this search strategy with references drawn from articles, reviews, book chapters and monographs.

RESULTS

Across generations of FHR projects, predictive studies have investigated behavioural, cognitive, psychometric, clinical, neuroimaging and other markers. Recent analyses have incorporated multivariate and multi-domain approaches to risk ascertainment, with generally modest results.

CONCLUSIONS

Although a broad range of risk factors has been identified, no individual marker or combination of markers can at this time enable accurate prospective prediction of emerging psychosis for individuals at FHR. We outline the complex and multi-level nature of psychotic illness, the myriad of factors influencing its development, and methodological hurdles to accurate and reliable prediction. Prospects and challenges for future generations of FHR studies are discussed in the context of early detection and intervention strategies.

Epigenetic epidemiology in psychiatry: A translational neuroscience perspective

Accumulating evidence from the field of neuroscience indicates a crucial role for epigenetic regulation of gene expression in development and aging of nervous system and suggests that aberrations in the epigenetic machinery are involved in the etiology of psychiatric disorders. Epidemiologic evidence on epigenetics in psychiatry, however, is currently very sparsely available, but is consistent with a mediating role for epigenetic mechanisms in bringing together inherited and acquired risk factors into a neurodevelopmental etiological model of psychiatric disorders. Here, we review evidence from the epidemiological and neuroscience literature, and aim to converge the evidence into an etiological model of psychiatric disorders that encompasses environmental, genetic and epigenetic contributions. Given the dynamic nature of the epigenetic machinery and the potential reversibility of epigenetic modifications, future well-designed interdisciplinary and translational studies will be of key importance in order to identify new targets for prevention and therapeutic strategies.

Predictors of psychosis: a 50-year follow-up of the Lundby population

Behavioural and neuropsychological vulnerability have been associated with an increased risk of psychosis. We investigated whether certain clusters of premorbid behavioural and personality-related signs and symptoms were predictors of nonaffective and/or affective psychosis and schizophrenia, respectively, in a 50-year follow-up of an unselected general community population. Total population cohorts from the same catchment area in 1947 (n = 2,503) and 1957 (n = 3,215) that had been rated for behavioural items and enduring symptoms were followed up to 1997 regarding first-incidence of DSM-IV nonaffective and/or affective psychosis. Attrition was 1-6%. The influence of the background factors, aggregated in dichotomous variables (predictors), on time to occurrence of nonaffective and/or affective psychosis was assessed by means of Cox regression models. In multivariate models the predictors nervous-tense, blunt-deteriorated, paranoid-schizotypal and tired-distracted were significantly associated with subsequent nonaffective and/or affective psychosis. In simple models, down-semidepressed, sensitive-frail and easily hurt were significantly associated with development of psychosis. When schizophrenia was analysed separately nervous-tense remained significant in the multivariate model, although blunt-deteriorated, paranoid-schizotypal and tired-distracted did not; and abnormal-antisocial reached significance. To conclude, we found some evidence for anxiety-proneness, affective/cognitive blunting, poor concentration, personality cluster-A like traits and interpersonal sensitivity to be associated with general psychosis vulnerability.

Differentiation of first-episode schizophrenia patients from healthy controls using ROI-based multiple structural brain variables

BACKGROUND

Brain morphometric measures from magnetic resonance imaging (MRI) have not been used to discriminate between first-episode patients with schizophrenia and healthy subjects.

METHODS

Magnetic resonance images were acquired from 34 (17 males, 17 females) first-episode schizophrenia patients and 48 (24 males, 24 females) age- and parental socio-economic status-matched healthy subjects. Twenty-nine regions of interest (ROI) were measured on 1-mm-thick coronal slices from the prefrontal and central parts of the brain. Linear discriminant function analysis was conducted using standardized z scores of the volumes of each ROI.

RESULTS

Discriminant function analysis with cross-validation procedures revealed that brain anatomical variables correctly classified 75.6% of male subjects and 82.9% of female subjects, respectively. The results of the volumetric comparisons of each ROI between patients and controls were generally consistent with those of the previous literature.

CONCLUSIONS

To our knowledge, this study provides the first evidence of MRI-based successful classification between first-episode patients with schizophrenia and healthy controls. The potential of these methods for early detection of schizophrenia should be further explored.

Epigenetic mediation of environmental influences in major psychotic disorders

The major psychotic disorders schizophrenia and bipolar disorder are etiologically complex involving both heritable and nonheritable factors. The absence of consistently replicated major genetic effects, together with evidence for lasting changes in gene expression after environmental exposures, is consistent with the concept that the biologic underpinnings of these disorders are epigenetic in form rather than DNA sequence based. Psychosis-associated environmental exposures, particularly at key developmental stages, may result in long-lasting epigenetic alterations that impact on the neurobiological processes involved in pathology. Although direct evidence for epigenetic dysfunction in both schizophrenia and bipolar disorder is still limited, methodological technologies in epigenomic profiling have advanced. This means that we are at the exciting stage where it is feasible to start investigating molecular modifications to DNA and histones and examine the mechanisms by which environmental factors can act upon the genome to bring about epigenetic changes in gene expression involved in the etiology of these disorders. Given the dynamic nature of the epigenetic machinery and potential reversibility of epigenetic modifications, the understanding of such mechanisms is of key relevance for clinical psychiatry and for identifying new targets for prevention and/or intervention.

Gene-environment interactions in schizophrenia: review of epidemiological findings and future directions

Concern is building about high rates of schizophrenia in large cities, and among immigrants, cannabis users, and traumatized individuals, some of which likely reflects the causal influence of environmental exposures. This, in combination with very slow progress in the area of molecular genetics, has generated interest in more complicated models of schizophrenia etiology that explicitly posit gene-environment interactions (EU-GEI. European Network of Schizophrenia Networks for the Study of Gene Environment Interactions. Schizophrenia aetiology: do gene-environment interactions hold the key? [published online ahead of print April 25, 2008] Schizophr Res; S0920-9964(08) 00170-9). Although findings of epidemiological gene-environment interaction (G x E) studies are suggestive of widespread gene-environment interactions in the etiology of schizophrenia, numerous challenges remain. For example, attempts to identify gene-environment interactions cannot be equated with molecular genetic studies with a few putative environmental variables "thrown in": G x E is a multidisciplinary exercise involving epidemiology, psychology, psychiatry, neuroscience, neuroimaging, pharmacology, biostatistics, and genetics. Epidemiological G x E studies using indirect measures of genetic risk in genetically sensitive designs have the advantage that they are able to model the net, albeit nonspecific, genetic load. In studies using direct molecular measures of genetic variation, a hypothesis-driven approach postulating synergistic effects between genes and environment impacting on a final common pathway, such as "sensitization" of mesolimbic dopamine neurotransmission, while simplistic, may provide initial focus and protection against the numerous false-positive and false-negative results that these investigations engender. Experimental ecogenetic approaches with randomized assignment may help to overcome some of the limitations of observational studies and allow for the additional elucidation of underlying mechanisms using a combination of functional enviromics and functional genomics.

Cerebral connectivity and psychotic personality traits. A diffusion tensor imaging study

This study aims to investigate the relationship between regional connectivity in the brain white matter and the presence of psychotic personality traits, in healthy subjects with psychotic traits. Thirteen healthy controls were administered the MMPI-2, to assess psychotic traits and, according to MMPI results, a dichotomization into a group of "high-psychotic" and "low-psychotic" was performed. Diffusion tensor imaging (DTI) was used as a non-invasive measure, in order to obtain information about the fractional anisotropy (FA), an intravoxel index of local connectivity and, by means of a voxelwise approach, the between-group differences of the FA values were calculated. The "high-psychotic" group showed higher FA in the left arcuate fasciculus. Subjects with low scores for psychotic traits had significantly higher FA in the corpus callosum, right arcuate fasciculus, and fronto-parietal fibers. In line with previous brain imaging studies of schizophrenia spectrum disorders, our results suggest that psychotic personality traits are related to altered connectivity and brain asymmetry.

MMPI measures as signs of predisposition to mental disorder among adoptees at high risk for schizophrenia

The DSM-III-R diagnoses of a group of adoptees were predicted by the MMPI (Minnesota Multiphasic Personality Inventory) schizophrenia-related scales in the Finnish Adoptive Family Study. The sample consisted of 60 high-risk (HR) adopted-away offspring of biologic mothers with a diagnosis of broad schizophrenia spectrum and 76 low-risk (LR) control adoptees. They were assessed with the MMPI before the onset of any psychiatric disorder at a mean age of 24 years. High scores on the Psychopathic Deviate scale predicted psychiatric disorder at 11-year follow-up. Furthermore, LR adoptees', but not HR adoptees', mental disorders could be predicted with the MMPI scales Psychopathic Deviate and Golden-Meehl Indicators. These scales measure schizophrenia-related personality traits, including a social behavior, anhedonia, ambivalence, interpersonal aversiveness, and formal thought disturbances.

Interaction of genetic vulnerability to schizophrenia and Communication Deviance of adoptive parents associated with MMPI schizophrenia vulnerability indicators of adoptees

The aim of this study was to establish possible genotype-environment interaction in high-risk and low-risk adoptees' vulnerability to schizophrenia. The study population consisted of a subgroup of 41 adoptive families with a high genetic risk adoptee and 58 families with a low genetic risk adoptee from the Finnish Adoptive Family Study of Schizophrenia. Communication style was assessed based on the Communication Deviance (CD) of the adoptive parents, and the adoptees' vulnerability indicators were measured with the Minnesota Multiphasic Personality Inventory (MMPI). Taken separately, only the genetic liability to schizophrenia, but not the communication style of the adoptive parents, was significantly associated with the Lie, Correction and Hostility scales in the MMPI of the adoptees. Analyses of the genotype-environment interactions showed that the high-risk adoptees with high-CD rearing parents had an increased risk of vulnerability on the MMPI Social Maladjustment scale compared with the corresponding low-risk adoptees. Genetic vulnerability to schizophrenia and genotype-environment interaction are manifested in adoptees' MMPI.

Can personality traits help us explain disability in chronic schizophrenia?

Psychotic features have been considered the main determinant of psychosocial function in schizophrenia. However, other variables are likely to affect dysfunction in these patients. The authors' hypothesis is that personality traits in outpatients with chronic schizophrenia differ from traits found in the healthy population and may be associated with disability in this disorder. A total of 62 patients with schizophrenia were evaluated with the Eysenck Personality Questionnaire (EPQ) and the Tridimensional Personality Questionnaire (TPQ). Psychotic features were measured with the help of the Positive and Negative Syndrome Scale (PANSS). Disability was assessed with the Disability Assessment Schedule (DAS). A total of 43 healthy subjects were used as controls for personality measurements. Normative data for the study population was also used to evaluate results in patients. Patients with schizophrenia had higher levels of neuroticism (median in percentile 65) and lower levels of extraversion (median in percentile 25) than the healthy population. Results of the TPQ showed higher harm avoidance and lower reward dependence levels compared to the healthy population. After multiple regression tests, negative symptoms were the strongest predictor of disability in patients with schizophrenia. Neuroticism contributed independently to the DAS overall behavior and global judgement subscales scores (more negative symptoms and higher neuroticism resulted in worse functioning), but not to the social role subscale. Outpatients with chronic schizophrenia showed high levels of neuroticism, harm avoidance, and introversion. Neuroticism significantly contributes to the long-term deficits found in patients with schizophrenia.

Interpreting the association between cannabis use and increased risk for schizophrenia

Recent longitudinal studies from Sweden, the Netherlands, New Zealand, and Israel report that cannabis use during childhood and adolescence doubles the risk of later appearance of psychosis or schizophrenia, These data have been interpreted as indicating that cannabis has a causal effect along the pathway to psychosis. In this paper, we will offer an alternative explanation of these data. Recent investigations of patients with schizophrenia found increased density of cannabinoid receptors in the dorsolateral prefrontal cortex and the anterior cingulate cortex. Others reported higher levels of endogenous cannabinoids in the blood and cerebrospinal fluid of patients; these findings were independent of possible cannabis use. Several genetic studies have reported an association between genes encoding the cannabinoid receptor and schizophrenia. Thus, an alternative explanation of the association between cannabis use and schizophrenia might be that pathology of the cannabinoid system in schizophrenia patients is associated with both increased rates of cannabis use and increased risk for schizophrenia, without cannabis being a causal factor for schizophrenia.

Dimensions of premorbid functioning in schizophrenia: a review of neuromotor, cognitive, social, and behavioral domains

After a brief discussion of methods for studying the premorbid period in schizophrenia, the authors review relevant experimental literature to assess the validity of current theories. A critical review is provided that includes representative empirical investigations on premorbid functioning in schizophrenia in the domains of neuromotor, intellectual, academic, cognitive, social, emotional, and behavioral functioning. Limitations of past research, such as lack of specificity to schizophrenia populations, high incidences of false positives, questionable definitions of the premorbid period, inconsistent measures of premorbid functioning, and problems with the current method of DSM classification are discussed. Alternative approaches to studying early functioning in schizophrenia are highlighted.

Does personality at college entry predict number of reported pain conditions at mid-life? A longitudinal study

The purpose of this study was to evaluate whether personality traits, as assessed by the Minnesota Multiphasic Personality Inventory (MMPI), at time of college entry can predict the number of reported pain conditions at an approximate 30-year follow-up for 2332 subjects, 1834 men and 498 women, who were administered the MMPI on entry to the University of North Carolina (Chapel Hill) between 1964 and 1966. In 1997, a follow-up was conducted in which subjects were administered a self-report questionnaire regarding whether they had experienced 1 or more chronic pain conditions. Analyses of the relationship between the MMPI clinical scales at college entrance and the report of number of chronic pain conditions at follow-up were conducted. Among male participants, elevations of Scales 1 (Hypochondriasis), 3 (Hysteria), and 5 (Masculinity/Femininity) predicted increases in number of chronic pain conditions at follow-up. For female participants, elevations in Scales 1, 3, and 6 (Paranoia) predicted increases in number of chronic pain conditions at follow-up. The current study suggests that a statistically significant relationship exists between MMPI responses at college entry and reports of chronic pain conditions at mid-life.

PERSPECTIVE

This study found a small, but significant relationship between elevations on MMPI scales measuring hypochondriasis and hysteria and the report of chronic pain conditions at follow-up. The study is important because it is the first to examine how personality assessed in younger adults relates to the number of chronic pain conditions reported 30 years later.

MMPI Vulnerability Indicators for Schizophrenia and Attention Deficit Disorder: UCLA Family Study of Biological Parents of Offspring with Childhood-Onset Schizophrenia or ADHD

Minnesota Multiphasic Personality Inventory (MMPI) scores were examined for 50 parents of children with an onset of schizophrenia prior to 14 years of age, 153 parents of children with attention deficit hyperactivity disorder (ADHD), and 168 parents of community comparison children. The parents were participants in the UCLA Family Study. The mean scores on all standard MMPI scales were within normal limits for all three groups of participants. Parents of schizophrenia probands were significantly higher on scale Sc than parents of community comparison children. Previous research has shown that scale Sc may be associated with a genetic liability to developing schizophrenia. Thus, scale Sc shows promise as an indicator of a heightened risk for the development of schizophrenia. The parents of the ADHD probands were significantly higher on standard clinical scale Pd than community comparison parents. Mothers of both schizophrenia and ADHD probands shared some personality indicators of stress reactivity. Although this study, like all non-adoptee family studies, cannot disentangle genetic effects on the development of these personality characteristics from environmental effects, we speculate that the emotional distress resulting in higher levels of the MMPI characteristics seen in the patients' mothers reflects the impact of raising a psychiatrically ill offspring.

Psychometric Deviance Measured by MMPI in Adoptees at High Risk for Schizophrenia and Their Adoptive Controls

Psychometric deviance in personality traits as assessed by the Minnesota Multiphasic Personality Inventory (MMPI; Dahlstrom, Welsh, & Dahlstrom, 1982) was compared between adopted-away, high-risk (HR) offspring of schizophrenic biologic mothers and low-risk (LR) controls. A subsample of the Finnish Adoptive Family Study (Tienari et al., 2000) included 60 HR adoptees and 76 LR control adoptees who were tested by the MMPI before the onset of any psychiatric disorder at the mean age of 24 years. The HR group was found to be distinguishable based on deviant scores on the scales HOS and HYP, indicating emotional unresponsiveness, restricted affectivity, and decreased energy. These may also be considered possible premorbid and prodromal signs of future schizophrenia among the HR adoptees.

The Schizophrenia Proneness (SzP) scale: an MMPI-2 measure of schizophrenia liability

We examined the psychometric properties and construct validity for a Minnesota Multiphasic Personality Inventory-2 Schizophrenia Proneness (SzP) scale (Bolinskey et al., 2001) and provided normative statistics. Premorbid participants were offspring of parents with schizophrenia-related illness (SRI), with comparison groups of offspring of parents with major affective disorders and offspring of normals. Postmorbid participants were twins affected with SRI; their unaffected relatives served as a comparison group. Results suggest that an SzP T score of 65 or above is an effective indicator of personality processes associated with increased liability to developing SRI.

Childhood developmental abnormalities in schizophrenia: evidence from high-risk studies

According to cohort studies, individuals who develop schizophrenia in adulthood show developmental abnormalities in childhood. These include delays in attainment of speech and motor milestones, problems in social adjustment, and poorer academic and cognitive performance. Another method of investigating developmental abnormalities associated with schizophrenia is the high-risk (HR) method, which follows up longitudinally the development of children at high risk for schizophrenia. Most HR studies have investigated children who have a parent with schizophrenia. This review summarizes findings concerning childhood and adolescent development from 16 HR studies and compares them with findings from cohort, conscript, and family studies. We specifically addressed two questions: (1) Does the development of HR children differ from that of control children? (2) Which developmental factors, if any, predict the development of schizophrenia-spectrum disorders in adulthood? While the answer to the first question is affirmative, there may be other mechanisms involved in addition to having a parent with schizophrenia. Factors which appear to predict schizophrenia include problems in motor and neurological development, deficits in attention and verbal short-term memory, poor social competence, positive formal thought disorder-like symptoms, higher scores on psychosis-related scales in the MMPI, and severe instability of early rearing environment.

Minnesota Multiphasic Personality Inventory profile characteristics of schizotypal personality disorder

The goal of the present study was to determine whether precursors for psychopathology can be found in personality dimensions of the general population. Two hundred and 62 university students were compared with 41 schizophrenic patients and 18 patients with schizotypal personality disorder (SPD) on the Minnesota Multiphasic Personality Inventory (MMPI). Schizotypal personality disorder patients showed significantly elevated Pt and Si scales compared with the schizophrenic patients. Schizophrenia and SPD groups generally produced two-point codetypes of 6-8/8-6, 2-6/6-2, 7-8/8-7, and 7-8/8-7, 2-7/7-2, 6-8/8-6. A total of 77.5% of students had no codetype with a T-value of > or = 70, although the frequency of codetypes of spike 5, spike 0 and 2-7/7-2 was relatively high in the student group compared with the general population. Discriminant function analysis of the MMPI profiles revealed significant variance among the three groups. The overall rate of correct classification of the subjects into schizophrenia, SPD or university students was 90.3%. The first coefficient, mainly defined by a negative weight on the Sc scale, best distinguished the patients with either schizophrenia or SPD from the students. The second coefficient, defined by negative weights on the Sc and Si scales, and positive weights on the F and Ma scales identified patients with schizophrenia and SPD patients. The Harris-Lingoes subscales, which are supposed to provide the profile patterns characteristic of schizotypy, well discriminated the three groups. These results suggest the usefulness of the MMPI subscales for the detection of subjects with the SPD trait.

A new MMPI-derived indicator of liability to develop schizophrenia: evidence from the New York High-Risk Project

A large body of research indicates that the liability to develop schizophrenia is largely genetically mediated, although phenotypic expression requires environmental triggers/insults and/or epigenetic and/or stochastic factors. In an effort to identify the precise environmental factors that precipitate a predisposition to schizophrenia, researchers have implemented a high-risk model-the prospective study of offspring born to schizophrenic parents. As it is difficult to ascertain exactly which of the "high-risk" participants will actually develop the disorder, we examined the validity of an experimental MMPI scale, Schizophrenia Proneness (SzP), and the Moldin-Gottesman psychometric index to identify such individuals. Results suggest that the SzP scale can be an effective predictor of schizophrenia-related psychoses. A revised psychometric index is offered for further study.

Behavioral and intellectual markers for schizophrenia in apparently healthy male adolescents

OBJECTIVE

Subtle behavioral and intellectual abnormalities are often present in apparently healthy adolescents who later develop schizophrenia. The authors investigated whether these abnormalities can predict vulnerability for schizophrenia before the first psychotic manifestation.

METHOD

The study consisted of linking the Israeli Draft Board Registry with the National Psychiatric Hospitalization Case Registry. The draft board tests measure intelligence, social functioning, organizational ability, interest in physical activity, and individual autonomy. Patients (N = 509) were compared to nonpatients, i.e., adolescents not appearing in the National Psychiatric Registry (N = 9,215), matched to patients by age, gender, and school attended at time of testing.

RESULTS

Healthy male adolescents who were later hospitalized for schizophrenia had significantly lower test scores on all measures than adolescents not reported to the National Psychiatric Registry. The strongest predictors for schizophrenia were deficits in social functioning, organizational ability, and intellectual functioning. When patients were compared to matched nonpatients, the prediction model had a 75% sensitivity, a 100% specificity, a positive predictive value of 72%, and an overall rate of correct classification of 87.5%. Applied to the Israeli Draft Board Registry, the model yielded a sensitivity of 74.7%, a validated specificity of 99.7%, and a positive predictive value of 42.7%.

CONCLUSIONS

This study demonstrated that simple assessment tools can predict predisposition to schizophrenia in healthy male adolescents. The model's predictive ability does not change as a function of the time elapsed between testing and first hospitalization. This suggests that the model identifies apparently healthy individuals who will manifest the disease later who are not prodromal to psychosis. Easily applied tools allowing early identification of schizophrenia or vulnerability to it may enable early intervention.