Schizotypal Personality Questionnaire-Brief: Effect of invalid responding on factor structure analysis and scores of schizotypy

Season of birth and schizotypy in a sample of undergraduate students

PURPOSE

In line with the psychotic continuum theory, the study of psychometric schizotypy in non-clinical samples has been proposed as a convenient yet powerful method for studying the etiology of psychosis. Based on this paradigm, several studies explored the association between season of birth (SoB) and schizotypy but led to inconsistent results. Building on the analysis of the previous studies, in the present study, we aimed to advance our understanding by improving the methodology (using a homogeneous group, eliminating unreliable respondents, taking into account potential confounders) and the reporting.

METHODS

Subjects were recruited among undergraduate students from 3 Romanian Universities. To limit the potential influence of invalid response, we applied methods for detecting unreliable and/or biased questionnaires and excluded subjects with unreliable/ biased answers from the analyses. Schizotypal dimensions were measured using the Romanian translation of the 22-items Schizotypal Personality Questionnaire-Brief (SPQ-B). The association between schizotypy scores and season of birth was explored using linear regression.

RESULTS

In a sample of 484 undergraduate students from Romania, we found that being born in late winter/early spring (February and March) was associated to higher total schizotypy score and disorganization. Furthermore, we found that restricting the sample to subjects born in an urban environment increased the strength of the association.

CONCLUSION

This study is consistent with an association between SoB and the risk of psychotic disorders.

Emotional anticipation for dynamic emotional faces is not modulated by schizotypal traits: A Representational Momentum study

Schizotypy, a personality structure that resembles schizophrenia symptoms, is often associated with abnormal facial emotion perception. Based on the prevailing sense of threat in psychotic experiences, and the immediate perceptual history of seeing others' facial expressions, individuals with high schizotypal traits may exhibit a heightened tendency to anticipate anger. To test this, we used insights from Representational Momentum (RM), a perceptual phenomenon in which the endpoint of a dynamic event is systematically displaced forward, into the immediate future. Angry-to-ambiguous and happy-to-ambiguous avatar faces were presented, each followed by a probe with the same (ambiguous) expression as the endpoint, or one slightly changed to express greater happiness/anger. Participants judged if the probe was "equal" to the endpoint and rated how confident they were. The sample was divided into high (N = 46) and low (N = 49) schizotypal traits using the Schizotypal Personality Questionnaire (SPQ). First, a forward bias was found in happy-to-ambiguous faces, suggesting emotional anticipation solely for dynamic faces changing towards a potential threat (anger). This may reflect an adaptative mechanism, as it is safer to anticipate any hostility from a conspecific than the opposite. Second, contrary to our hypothesis, high schizotypal traits did not heighten RM for happy-to-ambiguous faces, nor did they lead to overconfidence in biased judgements. This may suggest a typical pattern of emotional anticipation in non-clinical schizotypy, but caution is needed due to the use of self-report questionnaires, university students, and a modest sample size. Future studies should also investigate if the same holds for clinical manifestations of schizophrenia.

Schizotypal dimensions are associated with current but not former tobacco consumption

OBJECTIVES

We aimed to study the relationship between tobacco smoking and attenuated psychosis measures taking into account several aspects of tobacco consumption that to date have not been explored and that could help understand this association, such as age of onset, the influence of former consumption and the duration of abstinence.

METHODS

We investigated, in a sample of 580 students, the relationship between schizotypy (using the schizotypal personality questionnaire-brief in a Likert format) and smoking status, nicotine dependence (measured with the Fagerström test for nicotine dependence), age of onset of smoking and in former smokers, duration of smoking abstinence.

RESULTS

35.2% of the students were current smokers and 13.4% were former smokers. We found that current but not former smokers had higher scores of schizotypy (total, positive and disorganized) than non-smokers. We found no association between schizotypy scores and nicotine dependence or earlier age of onset of smoking. The duration of smoking abstinence, in former smokers, was inversely correlated to the score of positive and total schizotypy.

CONCLUSIONS

Our results suggest that tobacco has a reversible effect on schizotypy, but more studies with a different design (controlled, longitudinal) and a more thorough exploration of potential confounders (e.g. cannabis) are needed before a firm conclusion can be reached.

Genetic aspects in schizophrenia. Receptoral theories. Metabolic theories

Ties between schizophrenia (SCZ) and genetics are undeniably significant issue prone to be discussed in the nowadays psychology. Recent research on this domain focuses more on specific genes and heredity (specifically monozygotic pairs of twins) for diagnosing SCZ, than on environmental influences. SCZ is considered a multifactorial disease, thought to convert from a merger of risk and biological genes and environmental factors that could alter and reshape the trajectory of brain development. On this regard, this review sums up recent and innovative methods of distinguishing schizophrenic features from other mental illnesses in patients, based on chromosomal and genes changes. The term “reverse genetics” is no longer up to date, being replaced with “genome scanning” and “positional cloning”. For many researchers, genome scanning is continuing the reverse of the sensible strategy for detecting various important biological disorders, which may start from the discovery of a protein or any other molecule involved in a biological process, being followed by its gene cloning. Genes being discovered in this manner could become candidate genes for the disease. However, genome scanning occurs through testing each chromosomal segment (or mitochondrial genome) for the counter transmission of the disease.

Mapping psychotic-like experiences: Results from an online survey

Suggestions have been made that psychotic-like experiences (PLEs), such as hallucinatory and delusional experiences, exist on a continuum from healthy individuals to patients with a diagnosis of schizophrenia. We used the screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an online survey in a sample of more than 1,400 participants, we demonstrated that the QPE screening questions show satisfactory psychometric properties. Participants with mental disorders reported more frequent lifetime and current hallucinatory experiences than participants without mental disorders. Childhood experiences were rather low and ranged from 0.7% to 5.2%. We further replicated findings that young age, illegal drug use, lower level of education, and having parents with a mental disorder are associated with higher endorsement rates of PLEs. Finally, a binomial regression revealed that the mere presence of PLEs does not discriminate between individuals with and without a mental disorder. Taken together, the findings of the present study support existing models that both hallucinations and delusions exist on a structural and phenomenological continuum. Moreover, we demonstrated that the QPE screening questions can be used by themselves as a complementary tool to the full QPE interview.

Schizotypal traits in Swedish speaking psychiatric patients and non-psychiatric controls

Introduction: Recently, schizotypal personality traits were measured in a multinational sample recruited from 14 countries, however no Scandinavian cohort was included. The aim of this study was, therefore, to measure schizotypal personality traits in Swedish-speaking populations, with and without psychiatric disorders, and to investigate the psychometric properties of the Swedish version of the Schizotypal Personality Questionnaire-Brief (SPQ-B).Methods: The SPQ-B results from 50 psychiatric patients were compared to controls (n = 202). An additional sample of 25 controls completed the full SPQ twice and we calculated test-retest reliability for SPQ and SPQ-B. We estimated the internal consistency for SPQ-B and SPQ-B factors with omega. We compared the results of SPQ-B (M and SD) in patient and control groups to corresponding results worldwide.Results: We found similarity between our SPQ-B scores and those from other published samples. SPQ-B showed good internal consistency and acceptable test-retest correlations. The results indicate that the Swedish version of the instrument is valid and can differentiate psychiatric cohorts from non-psychiatric controls.Conclusion: The Swedish version of the SPQ-B exhibit good psychometric properties and is useful for assessing schizotypal traits in clinical and non-clinical populations.