Cluster A Personality Disorders: Schizotypal, Schizoid and Paranoid Personality Disorders in Childhood and Adolescence

Schizophrenia spectrum disorders in children and adolescents: Clinical, phenomenological, diagnostic, and prognostic features across subtypes

Schizophrenia spectrum disorders (SSD) typically have a diagnostically recognizable onset in young adulthood, yet it is not unusual that help-seeking due to initial SSD-related clinical manifestations emerge in earlier developmental phases, such as childhood and adolescence. Varieties of SSD manifestations in children and adolescents can be distinguished according to variations in clinical expressivity, severity and timing (i.e. developmental stage). Some individuals may reach the full clinical threshold for a diagnosis of schizophrenia according to the same descriptive diagnostic criteria used for adults, and in this case, it's possible to distinguish a pre-pubertal onset in childhood (aka Very Early Onset Schizophrenia, VEOS) and a post-pubertal onset in adolescence (aka Early Onset Schizophrenia, EOS). Other individuals may not reach such clinically overt diagnostic threshold but nonetheless present Childhood Schizotypal Disorder (CSD) or a Clinical High-Risk for Psychosis (CHRP). While EOS is clinically more similar to the canonical adult-onset presentation, the other 3 subgroups (i.e. VEOS, CSD, CHRP) present more nuances and specific clinical characteristics, which require ad-hoc developmental and phenomenological considerations for appropriate differential diagnosis and prognosis. Therefore, current scoping review intends to saturate such knowledge gap with respect to early SSD-phenotypes.

The Inner World and Formation of the Paranoid Personality Type in Persons with Intellectual Disabilities

This study investigates the progression of paranoid personality disorder (PPD) and its influence on social interactions. Contemporary research indicates that genetic predispositions and extrinsic variables, such as crisis events, play a role in the development of PPD. Individuals with PPD frequently struggle to form enduring social relationships as a result of their prevailing negative thoughts, hostility, and unwillingness to compromise. The study emphasizes the need for prompt psychological support in overcoming stereotyped cognition and diminishing social seclusion among individuals with personality disorders. The study employs a theoretical and methodological framework that integrates analytical research methodologies and content analysis of psychotherapy interventions for individuals with neuropsychiatric conditions. The findings uncover challenges about psychological adjustment, emotional control, and interpersonal communication abilities among patients with PPD. This article also presents contemporary psychotherapy approaches that aid in recovering mental well-being. Furthermore, a pragmatic framework for the diagnosis and treatment of PPD in psychotherapy has been created. The findings collected in this study hold great importance for professionals in the fields of education and social work, as well as practical value for psychologists and psychotherapists who offer support to those at risk of developing neuropsychiatric illnesses.

Co-occurrence of borderline and schizotypal personality disorders: a scoping review

BACKGROUND

The historical concept of borderline conditions refers to the pathology on the border between neurosis and psychosis. In DSM-III the conditions were divided into specific but also somewhat overlapping diagnostic criteria for Borderline Personality Disorder (BPD) and Schizotypal Personality Disorder (SPD). This phenomenological overlap, which results in co-occurrence of the two diagnoses, remains a clinical challenge to this day.

METHODS

To address this issue we examined the co-occurrence of SPD and BPD according to the established DSM-IV/-5 diagnostic criteria. A literature search was conducted including studies that employed a structured interview with defined BPD and SPD criteria.

RESULTS

Studies from 20 samples were included (i.e. 15 patients, 3 community and 2 forensic samples). For patients diagnosed primarily with BPD, 1-27% also met the criteria for SPD and for patients diagnosed primarily with SPD, 5 - 33% showed co-occurrence with BPD. In the forensic samples, co-occurrence for primary BPD was 10% and 67 - 82% for primary SPD. In the community samples, co-occurrence for primary BPD was 29% and 50% for primary SPD. The pattern of co-occurrence across community samples was particularly heterogeneous.

CONCLUSION

The identified co-occurrences for BPD and SPD were considerably sample-dependent, and samples and measurements were generally too heterogeneous for a precise meta-analysis. Forensic and community samples generally showed higher co-occurrences, but these findings were characterized by potential methodological limitations.

[Controversial issues of diagnosis and theoretical concepts of schizophrenia in childhood]

The article presents modern approaches to classification, presents debatable diagnostic issues, including the differences between domestic approaches to the diagnosis of schizophrenia in childhood from foreign taxonomies. The modern hypothesis of the etiological continuum of schizophrenic and autistic spectrum disorders is discussed, as well as clinical models of manifest stages of schizophrenia in childhood, with an emphasis on the influence of the age factor on the clinic, dynamics and prognosis of diseases.

A new scale for the screening of childhood early psychotic symptoms

This study aimed to develop a new scale, the Early Psychotic Symptoms screening scale (EPSy), to assess the prodromes of psychotic symptoms in children aged 4 to 13 years. Two versions were proposed: one to assess the child's current behavior and one to assess the child's behavior when he/she was 2 years old. The second aim of this study was to investigate the presence of these symptoms at the age of 2 years and their evolution up to the child's current age. The analysis of EPSy identified three main factors, namely mistrust/paranoia, perceptual aberrations/hallucinations and disorganized symptoms. It has good psychometric properties. Data also shows that, independently of the participant's age, the total score on the 2-years-old version predicts the total score on the current-age version, and this is also the case for each individual factor. Finally, it is of clinical interest since it makes it possible to describe symptomatology both at age 2 and at the child's present age depending on the group to which the children are assigned (control children, psychotic children, non-psychotic children).

Connectome-based predictive modeling predicts paranoid ideation in young men with paranoid personality disorder: a resting-state functional magnetic resonance imaging study

Paranoid personality disorder (PPD), a mental disorder that affects interpersonal relationships and work, is frequently neglected during diagnosis and evaluation at the individual-level. This preliminary study aimed to investigate whether connectome-based predictive modeling (CPM) can predict paranoia scores of young men with PPD using whole-brain resting-state functional connectivity (rs-FC). College students with paranoid tendencies were screened using paranoia scores ≥60 derived from the Minnesota Multiphasic Personality Inventory; 18 participants were ultimately diagnosed with PPD according to the Diagnostic and Statistical Manual of Mental Disorders and subsequently underwent resting-state functional magnetic resonance imaging. Whole-brain rs-FC was constructed, and the ability of this rs-FC to predict paranoia scores was evaluated using CPM. The significance of the models was assessed using permutation tests. The model constructed based on the negative prediction network involving the limbic system-temporal lobe was observed to have significant predictive ability for paranoia scores, whereas the model constructed using the positive and combined prediction network had no significant predictive ability. In conclusion, using CPM, whole-brain rs-FC predicted the paranoia score of patients with PPD. The limbic system-temporal lobe FC pattern is expected to become an important neurological marker for evaluating paranoid ideation.

[Assessment of the initial period of schizotypal disorder in childhood]

OBJECTIVE

To identify developmental features, the presence of hereditary burden, social adaptation, the structure of early psychopathological disorders in pediatric patients with schizotypal disorder (STD) and their relationship with the age of manifestation and the clinical structure of the disease.

MATERIAL AND METHODS

The study included 150 patients aged 7 to 16 years with a diagnosis of SD, of which 48 were female and 102 were male. Based on the age of onset of the first stable psychopathological disorders, at the stage preceding the diagnosis of SD, 5 groups of patients were identified: up to 3 years (n=38), from 4 to 6 years (n=36), from 7 to 10 years (n=15), 11-13 (n=41), 14-16 years old (n=20). The study used clinical-psychopathological, clinical-catamnestic, with a retrospective analysis, neurological, pathopsychological, psychometric and statistical research methods.

RESULTS

A high frequency of deviations from normative parameters in early psychomotor development was found in 99 (65%) patients with STD. Mental retardation was observed in 23 (15%) patients, dissociation in mental development was detected in a significant number of patients - 62 (41%). At the same time, the most significantly more frequent and pronounced were violations in the two youngest groups with the onset of psychopathological disorders up to 6 years. In these groups, there was also more often a deficit in three areas at once - emotional, motivational and volitional (38%) compared with the 4th group (13%). In groups 1 and 2, a deficit in intellectual development was also characteristic, which was reflected in academic indicators. High performance in the primary grades was observed in 16% of patients in the 1st group versus 60% in the 5th, and poor performance was found in 37% in the 1st group and only 5% in the 5th. The relationship of clinical variants of STD with the selected groups was revealed. The diagnosis of schizotypal personality disorder was significantly more often (66%) diagnosed in patients from group 1 compared with groups 3 and 5. In group 2, this diagnosis was established in a third of cases. The diagnosis of the psychopathic variant of STD was predominant in patients with the onset of the disorder between 7 and 13 years of age. The neurosis-like variant had a clear tendency to become more frequent with older age, reaching statistically significant differences in group 5 compared to group 1.

CONCLUSION

The age of onset and duration of persistence of psychopathological disorders determines the level of negative changes that have formed at the stage of the disease preceding the onset of distinct clinical symptoms of STD. Age at onset determines the predominant positive disorder.

The SSQ model of schizophrenic prodromal unfolding revised: An analysis of its causal chains based on the language of directed graphs

Objective

Except in broad outline, little is known about the most likely symptomatic trajectories in prodromal schizophrenia. The aim of this study is to delineate these pathways.

Methods

Taking into account existing clinical knowledge, the causal relationships between the 12 prodrome scales of the Schizotypic Syndrome Questionnaire (SSQ) were examined in a general-population sample by applying the mathematical theory of directed graphs. Use was made of two discovery algorithms implemented in the Tetrad-4 program, as well as of the graphical DAGitty program to test whether a particular model holds.

Results

A promising model was selected that may describe the causal pathways in schizophrenic prodromal unfolding. Testing this model by means of DAGitty, it was shown that the minimal testable implications, listed as conditional independences, and the direct and total effects in the model, identified after correction for bias, were as hypothesized. For practical reasons, a simpler version of the resulting SSQ model, containing only its principal pathways, was provided.

Conclusions

Although resembling an earlier model that was based on a series of LISREL analyses, the present model was believed to provide a more dependable description of schizophrenic prodromal unfolding, as it relies on methods that are less subject to the limitations involved in SEM.

Structural and functional brain abnormalities in children with schizotypal disorder: a pilot study

Schizotypal disorder lies in the schizophrenia spectrum and is widely studied in adult populations. Schizotypal disorder in children (SDc) is less well described. This study examined brain morphological and functional connectivity abnormalities in SDc (12 SDc and 9 typically developing children), focusing on the default mode and executive control brain networks. Results indicated that SDc is associated with reduced grey matter volume (GMV) in superior and medial frontal gyri, and increased resting-state functional connectivity between the superior frontal gyrus and inferior parietal lobule, compared to typically developing children (cluster-level FWE-corrected p < 0.05). The brain structure abnormality (GMV in left superior frontal gyrus) was correlated with clinical symptoms in SDc (r = −0.66, p = 0.026) and functional connectivity abnormality was correlated with extra-dimensional shifting impairments in all participants (r = 0.62, p = 0.011), suggesting their contribution to the underlying mechanisms of clinical presentation. These preliminary results motivate further work to characterize the neural basis of SDc and its significance as a risk factor for later psychosis.

Sensory prediction errors in the continuum of psychosis

Sensory prediction errors are fundamental brain responses that signal a violation of expectation in either the internal or external sensory environment, and are therefore crucial for survival and adaptive behaviour. Patients with schizophrenia show deficits in these internal and external sensory prediction errors, which can be measured using electroencephalography (EEG) components such as N1 and mismatch negativity (MMN), respectively. New evidence suggests that these deficits in sensory prediction errors are more widely distributed on a continuum of psychosis, whereas psychotic experiences exist to varying degrees throughout the general population. In this paper, we review recent findings in sensory prediction errors in the auditory domain across the continuum of psychosis, and discuss these in light of the predictive coding hypothesis.

Attentional set-shifting and social abilities in children with schizotypal and comorbid autism spectrum disorders

OBJECTIVE

While diagnostically independent, autism and schizotypal disorders can co-occur. Their concurrent impact on outcomes and phenotypes has not been investigated. We investigated the impact of comorbid autism and schizotypal disorders in children on executive functioning and socio-pragmatic skills - core features of both disorders.

METHOD

Executive functioning (assessed with the Cambridge Neuropsychological Test Automated Battery) and socio-pragmatic skills (assessed using the Melbourne Assessment of Schizotypy in Kids) were investigated in a total of 67 (6-12 year old) children with autism ( n = 15; M/F = 10/5), schizotypal disorder ( n = 8; M/F = 5/3) and comorbid autism and schizotypal disorder ( n = 12; M/F = 5/7) and typically developing children ( n = 32; M/F = 17/15).

RESULTS

Both the autism and schizotypal disorder groups performed more poorly than the typically developing group on socio-pragmatic skills and overall performance (i.e. number of stages completed) of the intra-/extra-dimensional set-shifting task (all ps < 0.001). Clear distinctions between the autism and schizotypal groups were present in the intra-/extra-dimensional task relative to the typically developing group - the autism group had difficulties with extra-dimensional shifts ( p < 0.001), and the schizotypal disorder group with intra-dimensional shifts ( p = 0.08). Interestingly, the overall performance of the comorbid group on the intra-/extra-dimensional task was not significantly different from the typically developing group, and they were superior to both the autism ( p = 0.019) and schizotypal disorder ( p = 0.042) groups on socio-pragmatic skills.

CONCLUSION

The phenotypical overlap between autism and schizotypal disorders may be precipitated by different cognitive styles and/or mechanisms associated with attention and information processing. We propose that sustaining and switching attention represent two poles of irregularities across the autism and schizotypal spectra, which appear to converge in a compensatory manner in the comorbid group. Our findings highlight the importance of investigating children with a dual diagnosis of autism and schizotypal disorders, and raise intriguing questions about possible mechanisms to explain the attenuated impairment observed in the group of children with comorbid autism and schizotpyal disorders.

Understanding adolescent personality pathology from growth trajectories of childhood oddity

Research on developmental trajectories of early maladaptive features for understanding later personality disorders (PDs) is increasingly recognized as an important study area. The course of early odd features is highly relevant in this regard, as only a few researchers have addressed childhood oddity in the context of emerging PDs. Using latent growth modeling, the current study explores growth parameters of odd features in a mixed sample of Flemish community and referred children (N = 485) across three measurement waves with 1-year time intervals. Personality pathology was assessed at a fourth assessment point in adolescence. Beyond a general declining trend in oddity characteristics, the results demonstrated that both an early onset and an increasing trend of oddity-related characteristics over time are independent predictors of adolescent PDs. Childhood oddity tends to be the most manifest precursor for PDs with a core oddity feature (i.e., the schizotypal and borderline PD), but also appears to predict most of the other DSM-5 PDs. Results are discussed from an overarching developmental framework on PDs (Cicchetti, 2014), specifically focusing on the principle of multifinality. From a clinical perspective, the significance of increasing or steady-high childhood oddity trajectories for adolescent PDs highlights the relevance of systematic screening processes across time.

A Case Study of Paternal Filicide-Suicide: Personality Disorder, Motives, and Victim Choice

Although evidence with respect to its prevalence is mixed, it is clear that fathers perpetrate a serious proportion of filicide. There also seems to be a consensus that paternal filicide has attracted less research attention than its maternal counterpart and is therefore less well understood. National registries are a very rich source of data, but they generally provide limited information about the perpetrator as psychiatric, psychological and behavioral data are often lacking. This paper presents a fully documented case of a paternal filicide. Noteworthy is that two motives were present: spousal revenge as well as altruism. The choice of the victim was in line with emerging evidence indicating that children with disabilities in general and with autism in particular are frequent victims of filicide-suicide. Finally, a schizoid personality disorder was diagnosed. Although research is quite scarce on that matter, some research outcomes have showed an association between schizoid personality disorder and homicide and violence.

Bridging the gap: the assessment and treatment of adolescent personality disorder in routine clinical care

Despite a marked increase in research supporting the assessment, diagnosis and treatment of personality disorder (PD) in adolescence, clinicians continue to be reluctant to apply treatment guidelines and psychiatric nomenclature in routine clinical care. This gap arises from several beliefs: (1) psychiatric nomenclature does not allow the diagnosis of PD in adolescence; (2) certain features of PD are normative and not particularly symptomatic of personality disturbance; (3) the symptoms of PD are better explained by other psychiatric syndromes; (4) adolescents' personalities are still developing and therefore too unstable to warrant a PD diagnosis; and (5) because PD is long-lasting, treatment-resistant and unpopular to treat, it would be stigmatising to label an adolescent with borderline personality disorder (BPD). In this paper, the empirical evidence challenging each of these beliefs is evaluated in the hope of providing a balanced review of the validity of adolescent PD with a specific focus on BPD. The paper concludes with recommendations on how routine clinical care can integrate a PD focus.

Structural alterations of the pyramidal pathway in schizoid and schizotypal cluster A personality disorders

AIM

Schizoid (ScPD) and Schizotypal (SPD) personality disorders are rare and severe disorders. They are associated with high liability to schizophrenia and present an attenuated form of its negative symptoms, which are considered a putative endophenotype for schizophrenia. The trans-diagnostic study of negative symptoms in non-psychotic populations such as ScPD/SPD might provide useful markers of a negative-symptom domain; however, little is known about their neurobiological substrates. The aim of the study was to investigate differences in gray and white matter volumes in subjects with ScPD/SPD compared to a group of healthy controls.

METHODS

Structural magnetic resonance images were obtained from 20 never-psychotic subjects with ScPD/SPD and 28 healthy controls. Resulting values from clusters of differences were correlated in patients with relevant clinical variables (O-LIFE scale).

RESULTS

ScPD/SPD presented greater bilateral white matter volume compared to healthy controls in the superior part of the corona radiata, close to motor/premotor regions, which correlated with the O-LIFE subtest of cognitive disorganization. No differences were found in regional gray matter or global gray/white matter volumes.

CONCLUSION

Greater volumes in motor pathways might relate to cognitive symptoms and motor alterations commonly present in schizophrenia-related disorders. Given the established link between motor signs and psychosis, structural alterations in motor pathways are suggested as a putative biomarker of a negative-symptom domain in psychosis subject to further testing.

Childrens' left-turning preference is not modulated by magical ideation

The literature on human turning preferences is inconsistent. While the few studies with children below 14 years of age uniformly describe an overall left-turning (counterclockwise) tendency, a recent Internet study with more than 1500 adults found a right-sided (clockwise) bias. We set out to investigate spontaneous turning behaviour in children age 5-3 years and, based on neuropsychiatric work in adults, also explored a potential association with magical thinking. Findings indicated a clear left-turning preference, independent of a participant's sex and handedness. Whether a child responded a question about the existence of extrasensory communication in the affirmative or not was unrelated to direction and size of turning bias and lateral preference. Our results are consistent with a left-sided turning preference reported for children, but in opposition to the clockwise bias recently described in a large-scale study with adults. Whether they point to a maturational gradient in the preferred direction of spontaneous whole-body rotation or rather to a lack of comparability between measures used in observational versus Internet-based studies remains to be further investigated. Regarding a purported association between body turns and magical thinking, our study is preliminary, as only one single question was used to probe the latter.

The Melbourne assessment of Schizotypy in kids: a useful measure of childhood schizotypal personality disorder

Despite being identified as a high risk cohort for psychosis, there has been relatively little research on the clinical presentation and assessment of Schizotypal Personality Disorder (SPD) in childhood. The current study aimed to develop a measure of childhood SPD (Melbourne Assessment of Schizotypy in Kids (MASK)) and assess discriminant validity against another neurodevelopmental disorder, autism spectrum disorder (ASD). Sixty-eight children aged between 5 and 12 (21 SPD, 15 ASD, and 32 typically developing) and their parents were administered the MASK. The MASK is a 57-item semistructured interview that obtains information from the child, their parents, and the clinician. The results showed high internal consistency for the MASK and higher scores in the SPD group. A factor analysis revealed two MASK factors: social/pragmatic symptoms and positive schizotypal symptoms. Both factors were associated with SPD, while only the social/pragmatic factor was associated with ASD. Within the two clinical groups, a receiver operating characteristic curve showed that the MASK (cut-off score: 132 out of 228) was a good indicator of SPD diagnosis. These preliminary MASK findings were reliable and consistent and suggest that childhood SPD is characterised by complex symptomology distinguishable from ASD.

The influence of comorbid personality disorders on recovery from depression

PURPOSE

The impact of personality disorders on the treatment of and recovery from depression is still a controversial topic. The aim of this paper is to provide more information on what has led to this disagreement.

MATERIALS AND METHODS

Clinician-rated Hamilton Depression Rating Scale (HAMD) scores were assessed among 82 depressed outpatients who were receiving a routine treatment combination of antidepressant medication and psychosocial intervention. The participants were followed up over five visits at 3-month intervals: at the baseline, at 3, 6, 9 and 12 months. Personality disorders were assessed after the last visit in accordance with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. These repeated measures were used to explore the impact of personality disorders on HAMD scores by using a linear mixed model.

RESULTS

Among the four personality clusters that were used (A, B, C, and mixed), only those in cluster B and in the mixed cluster were found to take significantly longer than those without personality disorders, for reduction in HAMD scores over the course of treatment.

CONCLUSION

In this study, the impact of personality disorders on treatment outcomes varied with the way that the personality disorder variables were described and used as independent predictors. This is because the outcomes were influenced by the impact weight of each personality disorder, even within the same cluster.

Factor Analysis Demonstrates a Common Schizoidal Phenotype within Autistic and Schizotypal Tendency: Implications for Neuroscientific Studies

Behavioral and cognitive dysfunction, particularly social and communication impairments, are shared between autism and schizophrenia spectrum disorders, while evidence for a diametric autism-positive schizophrenia symptom profile is inconsistent. We investigated the shared phenotype at a personality trait level, particularly its resemblance to schizoid personality disorder, as well as differential aspects of the autism-schizophrenia model. Items of the autism spectrum quotient (AQ) and schizotypal personality questionnaire (SPQ) were pseudo-randomly combined, and were completed by 449 (162 male, 287 female) non-clinical participants aged 18-40. A factor analysis revealed three factors; the first represented a shared social disorganization phenotype, the second reflected perceptual oddities specific to schizotypy while the third reflected social rigidity specific to autism. The AQ and SPQ were strongly correlated with Factor 1 (AQ: r = 0.75, p < 0.001; SPQ: r = 0.96, p < 0.001), SPQ score was correlated with Factor 2 (r = 0.51, p < 0.001), particularly in cognitive-perceptual features (r = 0.66, p < 0.001), and AQ score was strongly correlated with Factor 3 (r = 0.76, p < 0.001). Furthermore, there was no relationship between Factor 1 and Factor 2. Thus, there is robust evidence for a shared social disorganization phenotype in autistic and schizotypal tendency, which reflects the schizoid phenotype. Discriminating and independent dimensions of schizotypal and autistic tendency exist in Factors 2 and 3, respectively. Current diagnostic protocols could result in different diagnoses depending on the instrument used, suggesting the need for neuromarkers that objectively differentiate autistic and schizotypal traits and resolve the question of commonality versus co-morbidity.

The significance of at-risk symptoms for psychosis in children and adolescents

The early detection and treatment of people at risk for psychosis is currently regarded as a promising strategy in fighting the devastating consequences of psychotic disorders. Currently, the 2 most broadly used sets of at-risk criteria, that is, ultra-high risk (UHR) and basic symptom criteria, were developed mainly in adult samples. We review the data regarding the presence and relevance of at-risk symptoms for psychosis in children and adolescents. The few existing studies suggest that attenuated psychotic symptoms (APS) and brief limited intermittent psychotic symptoms (BLIPS) do have some clinical relevance in young adolescents from the general population. Nevertheless, their differentiation from atypical psychotic symptoms or an emerging schizotypal personality disorder, as well as their stability and predictive accuracy for psychosis, are still unclear. Further, standard interviews for UHR criteria do not define a minimum age for the assessment of APS and BLIPS or guidelines as to when and how to include information from parents. APS and basic symptoms may be predictive of conversion to psychosis in help-seeking young adolescents. Nevertheless, the rate and timing, and thus the required observation time, need further study. Moreover, no study has yet addressed the issue of how to treat children and adolescents presenting with at-risk symptoms and criteria. Further research is urgently needed to examine if current at-risk criteria and approaches have to be tailored to the special needs of children and adolescents. A preliminary rationale for how to deal with at-risk symptoms for psychosis in clinical practice is provided.

Measurement invariance of the Schizotypal Personality Questionnaire-Brief across gender and age

The purpose of this study was to examine the dimensional structure and measurement invariance of the Schizotypal Personality Questionnaire-Brief (SPQ-B) (Raine and Benishay, 1995) across sex and age in a representative sample of nonclinical adolescents and young adults. The sample consisted of 1789 adolescents and young adults (42.1% males), with a mean age of 17.1years (S.D.=2.9). The results indicated that the Likert version of the SPQ-B showed adequate psychometric properties (α total score 0.89). The schizotypal personality models that presented the best fit indices were Raine et al.'s (1994) three-factor model and Stefanis et al.'s (2004) four-factor model. In addition, the results support the measurement invariance of the SPQ-B across sex and age. When the latent means of the schizotypal dimensions were compared across sex and age, statistically significant differences were found. Consistent with previous literature, schizotypal personality is a multidimensional construct whose structure appears invariant across sex and age. Future studies should examine the invariance of schizotypal personality across cultures, as well as using the SPQ-B as a screening method in the general population to detect individuals at risk for schizophrenia-spectrum disorders, given its rapid and easy administration.

Post-traumatic stress disorder and declarative memory functioning: a review

Declarative memory dysfunction is associated with post-traumatic stress disorder (PTSD). This paper reviews this literature and presents two frameworks to explain the nature of this dysfunction: that memory deficits are a product of neurobiological abnormalities caused by PTSD andlor that pre-existing memory deficits serve as a risk factor for the development of PTSD following trauma exposure. Brain regions implicated in declarative memory deficits include the hippocampus and prefrontal cortex, and imaging and biochemistry studies as they relate to memory dysfunction are described. Prospective and twin studies provide support for a risk factor model.