Dissociation between affective experience and motivated behaviour in schizophrenia patients and their unaffected first-degree relatives and schizotypal individuals.

BACKGROUND: The neuropsychological origins of negative syndrome of schizophrenia remain elusive. Evidence from behavioural studies, which utilised emotion-inducing pictures to elicit motivated behaviour generally reported that that schizophrenia patients experienced similar affective experience as healthy individuals but failed to translate emotional salience to motivated behaviour, a phenomenon called emotion-behaviour decoupling. However, a few studies have examined emotion-behaviour decoupling in non-psychotic high-risk populations, who are relatively unaffected by medication effects. METHODS: In this study, we examined the nature and extent of emotion-behaviour decoupling in in three independent samples (65 schizophrenia patients v. 63 controls; 40 unaffected relatives v. 45 controls; and 32 individuals with social anhedonia v. 32 controls). We administered an experimental task to examine their affective experience and its coupling with behaviour, using emotion-inducing slides, and allowed participants to alter stimulus exposure using button-pressing to seek pleasure or avoid aversion. RESULTS: Schizophrenia patients reported similar affective experiences as their controls, while their unaffected relatives and individuals with high levels of social anhedonia exhibited attenuated affective experiences, in particular in the arousal aspect. Compared with their respective control groups, all of the three groups showed emotion-behaviour decoupling. CONCLUSIONS: Our findings support that both genetically and behaviourally high-risk groups exhibit emotion-behaviour decoupling. The familial association apparently supports its role as a putative trait marker for schizophrenia.

Trajectories of schizotypy and their emotional and social functioning: An 18-month follow-up study.

Schizotypy is a set of personality traits that convey liability to develop schizophrenia. Studying schizotypy in healthy individuals may facilitate the understanding of the psychopathological processes underlying schizophrenia. The present study aimed to examine the developmental trajectories of schizotypy over time using a longitudinal study design. The Chapman Scales for Psychosis Proneness were administered to 1541 college students at baseline, and subsequently at six-monthly intervals up to 18months. Latent class growth analysis was conducted to track the different trajectories. In addition, self-reported scales were used to measure idea of reference, emotional experiences and expression, stress and coping, as well as social functioning. We identified four latent classes with distinct trajectories: "nonschizotypy" group (LC1), "stable high schizotypy" group (LC3), "high reactive schizotypy" group (LC2) and "low reactive schizotypy" group (LC4). These findings suggest that there may be distinct developmental trajectories for schizotypy. Two groups may be of particular interest: the "stable high schizotypy" group that displayed the worst clinical and functioning outcomes on almost all measures and the "high reactive schizotypy" group characterized by a relatively rapid decline in functioning.

Evidence of structural invariance across three groups of Meehlian schizotypes.

According to Meehl's model of schizotypy, there is a latent personality organization associated with the diathesis for schizophrenia that can be identified in several ways. We sought to examine the structural invariance of four Chapman psychosis-proneness scales (CPPS) across three groups of putative schizotypes, namely, clinically-, biologically-, and psychometrically-identified schizotypes. We examined the factor structure of the Perceptual Aberration (PER), Magical Ideation (MIS), Revised Social Anhedonia (RSAS), and Revised Physical Anhedonia (RPAS) scales in 196 schizophrenia patients, 197 non-psychotic first-degree relatives, and 1,724 non-clinical young adults. The confirmatory factor analyses indicated that the best-fitting model was one in which there is a two-factor model with negative schizotypy (RSAS and RPAS) and positive schizotypy (PER and MIS). All three samples fit the model well, with Comparative Fit Indices>0.95 and Tucker Lewis Indices>0.90. The root mean square error of approximations were all small (P values⩽0.01). We also observed that for both anhedonia scales, the groups' mean scale scores varied in the hypothesized direction, as predicted by Meehl's model of schizotypy. All three Chinese samples, namely, the patients (clinical schizotypes), relatives (biologically-identified schizotypes), and non-clinical young adults (containing psychometrically-identified schizotypes) showed the same factorial structure. This finding supports the suitability of the CPPS for cross-cultural and/or genetic investigations of schizotypy.

Clinical Utility and Lifespan Profiling of Neurological Soft Signs in Schizophrenia Spectrum Disorders.

Neurological soft signs (NSSs) bear the promise for early detection of schizophrenia spectrum disorders. Nonetheless, the sensitivity and specificity of NSSs in the psychosis continuum remains a topic of controversy. It is also unknown how NSSs reveal neurodevelopmental abnormality in schizophrenia. We investigated the effect sizes of NSSs in differentiating individuals with schizophrenia spectrum disorders from individuals with other psychiatric conditions and from covariate-matched healthy subjects. We also investigated the partitioned age-related variations of NSSs in both schizophrenia and healthy individuals. NSSs were assessed by the abridged version of the Cambridge Neurological Inventory (CNI) in 3105 participants, consisting of healthy individuals (n=1577), unaffected first-degree relatives of schizophrenia patients (n= 155), individuals with schizotypal personality disorder (n= 256), schizophrenia patients (n= 738), and other psychiatric patients (n= 379). Exact matching and propensity score matching procedures were performed to control for covariates. Multiple regression was used to partition age-related variations. Individuals along the schizophrenia continuum showed elevated levels of NSSs, with moderate effect sizes, in contrast to other psychiatric patients who had minimal NSSs, as well as matched healthy controls. Furthermore, the age-and-NSS relationship in schizophrenia patients was represented by a flat but overall elevated pattern, in contrast to a U-shaped pattern in healthy individuals. In sum, NSSs capture a moderate portion of psychosis proneness with reasonable specificity. Lifespan profiling reveals an abnormal developmental trajectory of NSSs in schizophrenia patients, which supports the endophenotype hypothesis of NSSs by associating it with the neurodevelopmental model of schizophrenia.

Cross-cultural validation of the Depression Anxiety Stress Scale-21 in China.

The gap between the demand and delivery of mental health services in mainland China can be reduced by validating freely available and psychometrically sound psychological instruments. The present research examined the Chinese version of the 21-item Depression Anxiety Stress Scales (DASS-21). Study 1 administered the DASS-21 to 1,815 Chinese college students and found internal consistency indices (Cronbach's alpha) of .83, .80, and .82 for the Depression, Anxiety, and Stress subscales, respectively, and .92 for the total DASS total. Test-retest reliability over a 6-month interval was .39 to .46 for each of the 3 subscales and .46 for the total DASS. Moderate convergent validity of the Depression and Anxiety subscales was demonstrated via significant correlations with the Chinese Beck Depression Inventory (r = .51 at Time 1 and r = .64 at Time 2) and the Chinese State-Trait Anxiety Inventory (r = .41), respectively. Confirmatory factor analyses supported the original 3-factor model with 1 minor change (nonnormed fit index [NNFI] = .964, comparative fit index [CFI] = .968, and root mean square error of approximation [RMSEA] = .079). Study 2 examined the clinical utility of the Chinese DASS-21 in 166 patients with schizophrenia and 90 matched healthy controls. Patients had higher Depression and Anxiety but not Stress subscale scores than healthy controls. A discriminant function composed of the linear combination of 3 subscale scores correctly discriminated 69.92% of participants, which again supported the potential clinical utility of the DASS in mainland China. Taken together, findings in these studies support the cross-cultural validity of the DASS-21 in China. (PsycINFO Database Record

The nature of prospective memory deficit in patients with obsessive-compulsive disorder.

We comprehensively examined prospective memory (PM) performance in patients with obsessive-compulsive disorder (OCD), and explored the cognitive and psychopathological correlates of PM in this clinical population. Fifty-eight OCD patients and 58 healthy controls were assessed with computer-based PM tasks and related neurocognitive functions, and the participants also reported frequency of PM failures and compulsive behaviours in daily life. OCD patients had intact activity-based PM performance but had lower accuracy in time-based PM and longer reaction time to event-based PM cues compared to healthy controls. Among the neurocognitive functions, both the WCST (perseverative error) and the letter number span correlated with time-based PM. OCD patients reported similar number of PM failures in daily life as controls, which correlated with their intact event-based PM performance, suggesting a generally good insight into their PM functions. Neither clinician-assessed nor self-reported OCD symptoms correlated with PM performance. This study indicates that PM impairment tends to vary with the PM cue types in OCD patients. In addition, certain executive functions (i.e., mental shifting and updating) may contribute to time-based PM impairment in patients with OCD.

The neural basis of olfactory function and its relationship with anhedonia in individuals with schizotypy: An exploratory study.

Previous studies have established a linkage between olfactory deficits and negative symptoms in schizophrenia. However, it is not known whether olfactory function is associated with hedonic traits in individuals with schizotypy. Seventeen individuals with schizotypy and 18 age- and sex-matched controls participated in this study. Hedonic traits were assessed with the Chapman Scales for Physical and Social Anhedonia (CSAS and CPAS). Olfactory function was assessed with the Sniffin' Stick Test (olfactory threshold, odour discrimination and odour identification). All participants undertook a structural imaging scan for grey matter volume measurements. Individuals with schizotypy had significantly higher CSAS and CPAS scores than healthy controls. They had normal olfactory function. Their odour identification ability was inversely correlated with physical and social anhedonia. The volume of the right parahippocampal gyrus was positively associated with odour identification ability, and negatively associated with physical and social anhedonia. Furthermore, mediation analysis suggested that odour identification ability influences anhedonia through its effect on the right parahippocampal gyrus. No such relationship was found in controls. These findings suggest that there is a relationship between odour identification and anhedonia in individuals with schizotypy, and the association may be mediated by parahippocampal gyrus volume.

Re-visiting the nature and relationships between neurological signs and neurocognitive functions in first-episode schizophrenia: An invariance model across time.

The present study examined different types of neurological signs in patients with first-episode schizophrenia and their relationships with neurocognitive functions. Both cross-sectional and longitudinal designs were adopted with the use of the abridged Cambridge Neurological Inventory which comprises items capturing motor coordination, sensory integration and disinhibition. A total of 157 patients with first-episode schizophrenia were assessed at baseline and 101 of them were re-assessed at six-month interval. A structural equation model (SEM) with invariance model across time was used for data analysis. The model fitted well with the data at baseline assessment, X^2(21) = 21.78, p = 0.413, NFI = 0.95, NNFI = 1.00, CFI = 1.00, IFI = 1.00, RMSEA = 0.015. Subsequent SEM analysis with invariance model at six-month interval also demonstrated the same stable pattern across time and showed strong measurement invariance and structure invariance across time. Our findings suggest that neurological signs capture more or less the same construct captured by conventional neurocognitive tests in patients with schizophrenia. The measurement and structure of these relationships appear to be stable over time.

Course of neurological soft signs in first-episode schizophrenia: Relationship with negative symptoms and cognitive performances.

This prospective study examined the course of neurological soft signs (NSS) in patients with first-episode schizophrenia and its relationship with negative symptoms and cognitive functions. One hundred and forty-five patients with first-episode schizophrenia were recruited, 29 were classified as having prominent negative symptoms. NSS and neuropsychological measures were administered to all patients and 62 healthy controls at baseline. Patients were then followed-up prospectively at six-month intervals for up to a year. Patients with prominent negative symptoms exhibited significantly more motor coordination signs and total NSS than patients without prominent negative symptoms. Patients with prominent negative symptoms performed worse than patients without negative symptoms in working memory functions but not other fronto-parietal or fronto-temporal functions. Linear growth model for binary data showed that the prominent negative symptoms were stable over time. Despite general improvement in NSS and neuropsychological functions, the prominent negative symptoms group still exhibited poorer motor coordination and higher levels of NSS, as well as poorer working memory than patients without prominent negative symptoms. Two distinct subtypes of first-episode patients could be distinguished by NSS and prominent negative symptoms.

Experiential pleasure deficits in different stages of schizophrenia.

Prior research has found dampened anticipatory pleasure but relatively intact consummatory pleasure in people with first-episode and more chronic schizophrenia, but no study has examined anticipatory and consummatory pleasure across the schizophrenia spectrum. To confirm the factor structure of the Chinese version of the Temporal Experience Pleasure Scale (TEPS), which measures four components of anhedonia, we recruited 364 people with schizophrenia for confirmatory factor analysis. To examine anhedonia in people across the schizophrenia spectrum, we recruited people with first-episode (n=76) and chronic schizophrenia (n=45), people with schizotypal traits (n=210), first-degree relatives (n=45) of people with schizophrenia and healthy controls. Deficit in abstract anticipatory pleasure appeared to be most severe in people with chronic schizophrenia, while dampened abstract consummatory pleasure was observed in people with schizotypal personality features and in people with chronic schizophrenia. In addition, both abstract anticipatory and abstract consummatory pleasure were negatively correlated with negative schizotypal personality features and schizophrenia symptoms. Our results suggest that deficits in anticipatory pleasure are present across the schizophrenia spectrum, particularly in the abstract domain.

The Chapman psychosis-proneness scales: Consistency across culture and time.

The purpose of the present study was to examine the factor structure and the temporal stability of the Chapman psychosis-proneness scales in a representative sample of nonclinical Chinese young adults. The four psychosis-proneness scales evaluated were the Perceptual Aberration (PAS), Magical Ideation (MIS), revised Social Anhedonia (RSAS), and revised Physical Anhedonia (RPAS) scales. The sample consisted of 1724 young adults with a mean age of 18.8 years (S.D. = 0.84). The results of the confirmatory factor analyses indicated that the best fitting model was a two-factor model with positive schizotypy (PER and MIS) scales and negative schizotypy (RSAS and RPAS) scales. The data add to the growing literature indicating that the measurement of schizotypal traits is consistent across cultures. In addition, the results support the measurement invariance of the Chapman psychosis-proneness scales across time, i.e., there was ample evidence of test-retest reliability over a test interval of 6 months.

Developmental trajectories of schizotypal personality disorder-like behavioural manifestations: a two-year longitudinal prospective study of college students.

BACKGROUND: Previous evidence has shown that schizotypal personality disorder (SPD) is part of the schizophrenia spectrum. Few studies have examined latent classes in the developmental trajectories of SPD features over time in individuals with SPD features. METHODS: We adopted a longitudinal prospective study design to follow up a cohort of 660 college students during a two-year period. Participants' SPD-like symptoms and psychosocial function were measured by a comprehensive set of questionnaires that covered SPD features and cognitive, emotional, and psychosocial functions. Latent class growth analysis was used to examine the trajectory classes. RESULTS: Three trajectory classes were identified: a low, a medium, and a high SPD features group. Participants in the low group reported few SPD features and their symptoms declined over time. The medium group students had more SPD features than the low group and these symptoms stabilized during the follow up period. Participants in the high group reported the most SPD features and their symptoms increased over time. The three groups differed in paranoid thoughts, psychological distress, neurocognition function, and emotional expression over time. Results of multivariate regression analysis suggested that paranoid thoughts, emotional experience and prospective memory were predictors of social functioning in the high SPD feature group. CONCLUSIONS: Our findings suggest that individuals with SPD features may be delineated into different developmental subgroups and these subgroups differ significantly in psychosocial function. Delusions, emotion, and prospective memory may be important features to consider in early diagnosis and interventions for individuals predisposed to SPD and schizophrenia.