Familiality in a five-factor model of schizophrenia psychopathology: findings from a 16-month follow-up study

Predictive factors in early onset schizophrenia

Schizophrenia is a neurodevelopmental disorder, characterized by impairment in reasoning, affectivity and social relationships. Although the diagnosis of schizophrenia in children and adolescents has been challenged for many years, at present childhood-onset schizophrenia is considered and accepted as a clinical and biological continuum with the adult-onset disorder. The present study aimed to evaluate the influence of biological (psychiatric family history, perinatal factors), and socio-demographic factors (area of residence, gender) on the age at onset and severity of symptomatology in children and adolescent with schizophrenia. The data were collected from 2016 to 2019 and included 148 children and adolescents with schizophrenia. Data were analysed with statistical software (IBM SPSS 22, JASP and JAMOVI, Linear Regression Model, χ² tests, t-test, U-test). A positive familial history for psychiatric diseases was an important risk factor both for an early onset and for the severity of symptoms. Urbanicity was another studied risk factor, 61% of patients being from urban areas; no statistically significant correlations between urbanicity and age at onset and severity of symptoms were identified. There was no statistically significant gender difference in terms of age at onset and severity of symptoms. Moreover, no statistically significant correlations were found between perinatal factors and age at onset and severity of symptoms. Positive psychiatric family history showed a statistically significant influence on age at onset and symptoms severity in children and adolescent schizophrenia; no statistical significant impact on the aforementioned schizophrenia aspects was observed for urbanicity, gender or perinatal factors.

Family history of psychosis and outcome of people with schizophrenia in rural China: 14-year follow-up study

OBJECTIVE

This study examined the differences in 14-year outcomes of persons with schizophrenia with and without family history of psychosis in a rural community in China.

METHODS

All participants with schizophrenia (n=510) aged 15 years and older were identified in a 1994 epidemiological investigation of 123,572 people and followed up in 2004 and 2008 in Xinjin County, Chengdu, China.

RESULTS

Individuals with positive family history of schizophrenia had significantly younger age of first onset than those with negative family history of schizophrenia in 1994 and 2004. Compared with individuals with negative family history of schizophrenia, those with positive family history of schizophrenia had significantly higher rate of homelessness and lower rate of death due to other reasons in 10-year (2004) and 14-year follow-up (2008). There were no significantly differences of mean scores on PANSS, SDSS and GAF in 2008 between positive and negative family history groups.

CONCLUSIONS

The positive family history of schizophrenia is strongly related to younger age of onset, and may predict a poorer long-term outcome (e.g., higher rate of homelessness) in persons with schizophrenia in the rural community. The findings have implications for further studies on specific family-related mechanisms on clinical treatment and rehabilitation, as well as for planning and delivering of community-based mental health services.

Genetic Association of TCF4 and AKT1 Gene Variants with the Age at Onset of Schizophrenia

BACKGROUND

Age at onset (AAO) is a known prognostic indicator for schizophrenia and is hypothesized to correlate with cognition and symptom severity. TCF4 and AKT1 are schizophrenia risk genes involved in cognitive functions. The current study examined the interactive effects of TCF4 and AKT1 variants with gender, family history of psychiatric disorders and ethnicity on the AAO of schizophrenia.

METHODS

This study consisted of 322 patients with schizophrenia meeting the DSM-IV criteria. Six single nucleotide polymorphisms (SNPs) of TCF4 (rs12966547, rs8766, rs2958182, rs9960767, rs10401120 and rs17512836) and seven AKT1 SNPs (rs2498804, rs3803304, rs2494732, rs3730358, rs1130214, rs2498784 and rs3803300) were genotyped using the TaqMan® SNP genotyping-based assays method. The relationship of AAO with each variant was investigated using analyses of covariance.

RESULTS

Among the TCF4 variants, rs12966547 (p = 0.024) and rs8766 (p = 0.021) were significantly associated with earlier AAO. We found a lower average AAO in patients with the AA genotype of rs12966547, while the CT genotype of rs8766 was demonstrated to have a protective effect on AAO. For rs8766, there was significant gene × gender interaction (p = 0.012) in influencing AAO. However, these results were not significant after false discovery rate correction. Significant gene × ethnicity interactions were observed to influence AAO (p < 0.05). The Kaplan-Meier curve of the minor AA genotype of rs12966547 displayed a significant trend (p = 0.008) for onset after 19 years of age. Similarly, the minor CC genotype of rs8766 showed a significantly (p = 0.034) lower AAO compared to the TT genotype.

CONCLUSION

Our analyses suggest that individual risk genotypes may influence the risk of schizophrenia in an age-specific manner.

Typology of people with first-episode psychosis

AIMS

The aim of the current study was to create a typology of patients with first-episode psychosis based on sociodemographic and clinical characteristics, service use and outcomes using cluster analysis.

METHODS

Data from all respondents who were accepted into the Early Psychosis Intervention Programme (EPIP), Singapore from 2007 to 2011 were analysed. A two-step clustering method was carried out to classify the patients into distinct clusters.

RESULTS

Two clusters were identified. Cluster 1 comprised largely of younger people with mean age of 25.5 (6.0) years at treatment contact, who were predominantly male (55.3%), single (98.3%) and living with parents (86.3%). Cluster 1 had a higher proportion of people diagnosed with the schizophrenia spectrum disorder (71.4%) and with a positive family history of psychiatric illness. Patients in cluster 2 were generally older with a mean age of 33.6 (4.7) years and the majority were women (74.2%). Cluster 1 had people with higher Positive and Negative Syndrome Scale (PANSS) scores at baseline as compared with cluster 2. After a 1-year follow up, their scores were still poorer than their counterparts in cluster 2, especially for PANSS negative score. The functioning level of people in cluster 1 showed less improvement than the people in cluster 2 after a year of treatment.

CONCLUSIONS

There is a compelling need to develop new therapies and intensively treat young people presenting with psychosis as this group tends to have poorer outcomes even after 1 year of treatment.

Comorbid substance use disorders in schizophrenia: a latent class approach

Schizophrenia is a complex psychiatric disorder with a characteristic disease course and heterogeneous etiology. While substance use disorders and a family history of psychosis have individually been identified as risk factors for schizophrenia, it is less well understood if and how these factors are related. To address this deficiency, we examined the relationship between substance use disorders and family history of psychosis in a sample of 1219 unrelated patients with schizophrenia. The lifetime rate of substance use disorders in this sample was 50%, and 30% had a family history of psychosis. Latent class mixture modeling identified three distinct patient subgroups: (1) individuals with low probability of substance use disorders; (2) patients with drug and alcohol abuse, but no symptoms of dependence; and (3) patients with substance dependence. Substance use was related to being male, to a more severe disease course, and more acute symptoms at assessment, but not to an earlier age of onset of schizophrenia or a specific pattern of positive and negative symptoms. Furthermore, substance use in schizophrenia was not related to a family history of psychosis. The results suggest that substance use in schizophrenia is an independent risk factor for disease severity and onset.

The Relative Importance of Family History, Gender, Mode of Onset, and Age at Onsetin Predicting Clinical Features of First-Episode Psychotic Disorders

OBJECTIVE

Family history of psychosis, gender, mode of onset, and age at onset are considered prognostic factors important to clinicians evaluating first-episode psychosis; yet, clinicians have little guidance as to how these four factors differentially predict early-course substance abuse, symptomatology, and functioning. We conducted a "head-to-head comparison" of these four factors regarding their associations with key clinical features at initial hospitalization. We also assessed potential interactions between gender and family history with regard to age at onset of psychosis and symptom severity.

METHODS

Consecutively admitted first-episode patients (n=334) were evaluated in two studies that rigorously assessed a number of early-course variables. Associations among variables of interest were examined using Pearson correlations, χ² tests, Student's t-tests, and 2×2 factorial analyses of variance.

RESULTS

Substance (nicotine, alcohol, and cannabis) abuse and positive symptom severity were predicted only by male gender. Negative symptom severity and global functioning impairments were predicted by earlier age at onset of psychosis. General psychopathology symptom severity was predicted by both mode of onset and age at onset. Interaction effects were not observed with regard to gender and family history in predicting age at onset or symptom severity.

CONCLUSIONS

The four prognostic features have differential associations with substance abuse, domains of symptom severity, and global functioning. Gender and age at onset of psychosis appear to be more predictive of clinical features at the time of initial evaluation (and thus presumably longer term outcomes) than the presence of a family history of psychosis and a more gradual mode of onset.

Predicting 10-year quality-of-life outcomes of patients with schizophrenia and schizoaffective disorders

AIMS

This study aimed to determine predictors for 10-year good versus poor perceived general quality of life (QOL) outcomes from baseline variables in people with schizophrenia and schizoaffective disorder.

METHODS

We compared patients with poor versus good 10-year QOL outcomes using baseline clinical, personality-related variables, demographic and background characteristics. Logistic regression analysis was used for predicting the 10-year QOL outcomes from baseline data. One-hundred-eight patients completed the Quality-of-Life Enjoyment and Life Satisfaction Questionnaire, the Positive and Negative Syndromes Scale (PANSS), the Talbieh Brief Distress Inventory, and psychosocial questionnaires at baseline and 10 years later.

RESULTS

Logistic regression revealed six predictors of QOL outcomes: paranoid ideations (odds ratio [OR] 3.1), PANSS general psychopathology (OR 1.1), obsessiveness (OR 0.84), hostility (OR 0.4), PANSS positive scale scores (OR 0.4), and general QOL index (OR 0.4). This model classified 80.6% of the sample with good sensitivity (87% correctly identified 'poor outcome'), and specificity (71% correctly identified 'good outcome').

CONCLUSION

This study provides a pattern of baseline predictors for long-term QOL outcomes. Identified predictors are factors that can potentially be ameliorated, and thereby enhance the QOL of people with schizophrenia and schizoaffective disorder.

Family load estimates of schizophrenia and associated risk factors in a nation-wide population study of former child and adolescent patients up to forty years of age

OBJECTIVES

This nation-wide register-based study investigates the family load of schizophrenia (SZ) across three generations in affected families compared to control families. Furthermore the study compares the family load in case vs. control families considering the age of onset of the disorder in the cases. In addition, the study addresses the impact of certain socio-demographic risk factors, i.e. sex, region of residence, year of birth, month of birth, and maternal and paternal age at birth.

METHOD

A total of N=2020 child and adolescent psychiatric cases born between 1969 and 1985 registered in the Danish Central Psychiatric Register (DCPR) before the age of 18 developed SZ before the age of 40. N=5982 controls without any psychiatric diagnosis before age 18 were matched for age, sex, and residential region. Psychiatric diagnoses were also obtained on the first-degree relatives, i.e. parents, siblings, and offspring as a part of the Danish Three Generation Study (3GS). A family load was obtained by using various mixed regression models.

RESULTS

SZ did occur more often in case than in control families. Having a mother, father or a sibling with the disorder was proven to be a risk factor. The year of birth, the region of residence, and paternal age at birth (≥ 35) were associated with SZ. However, the family load was not dependent on age of onset of the case-proband. Furthermore, case relatives did not develop SZ earlier than control relatives.

CONCLUSIONS

These findings based on a very large and representative dataset provide further and solid evidence for the high family aggregation of SZ. The year of birth, the region of residence, and paternal age at birth play an additional role in the development of the disorder.

Family history of psychosis negatively impacts age at onset, negative symptoms, and duration of untreated illness and psychosis in first-episode psychosis patients

Family history (FH) of psychosis has been a focus of investigations attempting to explain the heterogeneity in schizophrenia. Previous studies have demonstrated that FH is associated with earlier age at onset, severity of positive and negative symptoms, and the duration of untreated illness (DUI). The current study examined the impact of FH on the clinical presentation and help-seeking behaviors of a well-characterized, first-episode sample. The present study utilized the Symptom Onset in Schizophrenia (SOS) Inventory, the Positive and Negative Syndrome Scale (PANSS), and structured interviews on FH to examine these relationships in a large (n=152) sample of predominantly African American patients. Results showed that patients with a first-degree FH of psychosis had a younger age at onset of both the prodrome and psychosis, but did not differ in duration of prodromal period. Furthermore, FH and sex interacted to influence severity of negative, but not positive symptoms. Finally, FH interacted with sex to influence both the DUI and DUP in that only males with FH had longer DUI and DUP. The findings have implications for understanding the impact of specific family-related mechanisms on both clinical and help-seeking factors, as well as for informing future family-based intervention efforts.

Environmental risk factors and their impact on the age of onset of schizophrenia: Comparing familial to non-familial schizophrenia

BACKGROUND AND AIMS

Several risk factors for schizophrenia have yet been identified. The aim of our study was to investigate how certain childhood and adolescent risk factors predict the age of onset of psychosis in patients with and without a familial component (i.e. a relative with schizophrenia or schizoaffective disorder).

METHODS

Aside from the age of onset of psychosis, we examined the risk factors for schizophrenia including obstetric complications, birth during winter or spring, behavioral deviances or delayed motor and speech development, exposure to adverse life events and exposure to substance use within a group of 100 patients (45 female, 55 male) with a mean age (± standard deviation) of 35.15 ± 13.21.

RESULTS

Birth complications and cannabis abuse are predictors for an earlier onset of schizophrenia in patients with non-familial schizophrenia. No environmental risk factors for an earlier age of onset in familial schizophrenia have been identified.

CONCLUSIONS

Certain environmental risk factors for schizophrenia seem to have an impact on the age of onset of psychosis in non-familial schizophrenia, they do not seem to have an impact on familial schizophrenia.

Neurodevelopmental liability to schizophrenia: the complex mediating role of age at onset and premorbid adjustment

Large individual variation in the clinical presentation of schizophrenia-spectrum disorders raises key questions regarding their aetiological underpinnings. In this respect, age at onset of the disorder is a particularly interesting marker of liability, as it has been reported to be associated with other signs of developmental compromise, such as male gender, increased presence of familial history of psychosis and poor premorbid adjustment, as well as a more severe clinical outcome in terms of cognition and symptomatology. The association between these variables has encouraged a neurodevelopmental perspective of the aetiological mechanisms involved in the pathophysiology of schizophrenia. However, the complex relationships within neurobiological liability markers, and between these markers and clinical outcome, remain to be understood. In the present study, we used a path-analytic approach to explore: i) the fit of the model to observed data; and both ii) direct and iii) indirect associations between the variables. In a sample of 106 patients with schizophrenia-spectrum disorders, we found a good fit of the model to the observed data, providing further evidence that supports a neurodevelopmental pathway to the disease in a subgroup of patients. However, the most parsimonious model showed complex relationships, where age at onset and premorbid functioning acted as mediators between gender, familial history of psychosis and clinical outcome. These findings refine earlier explanations of the neurobiological basis of schizophrenia, with potential applications in genetic studies based on more homogeneous forms of the disease. We further discuss the putative implications of our results in clinical practice and prevention policies.

Heritability estimates for psychotic symptom dimensions in twins with psychotic disorders

Factor analysis of psychotic symptoms frequently results in positive, negative, and disorganized dimensions, but heritability estimates have not yet been reported. Symptom dimensions are usually only measured in individuals with psychotic disorders. Here, it is valuable to assess influences acting via liability to psychosis and independent modifying effects. We estimated heritability for psychotic symptom dimensions, taking account of these issues. Two-hundred-and-twenty-four probandwise twin pairs (106 monozygotic, 118 same-sex dizygotic), where probands had psychoses, were ascertained from the Maudsley Twin Register in London (1948-1993). Lifetime history of DSM-III-R psychotic disorder and psychotic symptom dimensions was assessed from clinical records and research interviews and rated using the Operational Criteria Checklist. Estimates of heritability and environmental components of variance in liability were made with structural equation modeling using a causal-contingent common pathway model adapted for ascertainment from a clinical register. Significant heritability was found for DSM-III-R psychotic disorder (h² = 90%, 95%CI 68-94%) and the disorganized symptom dimension (h² = 84%, 95%CI 18-93%). The heritability for the disorganized dimension remained significant when influences acting through liability to psychosis were set to zero, suggesting that some influences on disorganization are modifying factors independent of psychosis liability. However, the relative extent of modifying factors versus influences acting through psychosis liability could not be clearly determined. To our knowledge, this study provides the first formal evidence of substantive heritability for the disorganized symptom dimension, and suggests that genetic loci influencing disorganization in individuals with psychoses are in some cases different from loci that influence risk of psychotic disorders themselves.

The impact of a family history of psychosis on age-at-onset and positive and negative symptoms of schizophrenia: a meta-analysis

The results of research on the relation of family history (FH) of psychosis with clinical presentation in schizophrenia have been mixed. To date, there have been no comprehensive reviews that have examined this body of research. The current review quantitatively evaluates research on the relation of FH with two aspects of schizophrenia, age-at-onset and symptom presentation. Studies investigating the influence of a FH on age-at-onset (N=15 studies), age-at-onset and sex (N=12 studies), and/or positive (N=11 studies) and negative symptoms (N=12 studies) in patients with schizophrenia were included in the meta-analyses. Results showed that FH has a small but significant impact on age-at-onset as well as negative symptoms. Of most interest was the finding that sex differences in age-at-onset are not observed in samples with a FH. Furthermore, there was a significant interaction between FH and sex with respect to negative symptoms. The findings of the current review are discussed in light of the diathesis-stress model. Theoretical assumptions and empirical research are reviewed to support the notion that FH influences susceptibility and presentation through similar mechanisms. Implications of the current findings, limitations of the review, and directions for future research are highlighted.

Neuroanatomical differences between familial and sporadic schizophrenia and their parents: an optimized voxel-based morphometry study

Symptomatic differences have been reported between patients with familial and sporadic schizophrenia. The present study examined neuroanatomical differences between the two subgroups and their parents using voxel-based morphometry. High-resolution T1-weighted images were obtained using 3 Tesla magnetic resonance imaging from 20 patients with schizophrenia (familial subgroup, n=10; sporadic subgroup, n=10), 20 of their parents (familial subgroup, n=10; sporadic subgroup, n=10) and 20 healthy volunteers. Gray matter density (GMD) was compared between groups on a voxel-by-voxel basis. Compared with the sporadic patients, the familial patients had significantly reduced GMD in the thalamus bilaterally. Reduction of GMD in bilateral thalami was also found in familial parents in comparison with sporadic parents. Compared with controls, both familial and sporadic patients had lower GMD involving bilateral insula, right temporal lobe, right occipital lobe, left lenticular nucleus and right cerebellum. However, only familial patients showed lower GMD than controls in the right thalamus. Compared with controls, only familial parents showed lower GMD in the right insula extending to the right temporal lobe and the right parietal lobule. The present data suggest that familial schizophrenia is associated with more severe structural abnormalities than sporadic schizophrenia, especially in the thalamus.

Twin study refining psychotic symptom dimensions as phenotypes for genetic research

We investigated which psychotic symptom dimensions are likely to be most useful as phenotypes for genetic linkage and association studies. Two hundred twenty-four probandwise twin pairs (106 monozygotic,118 same-sex dizygotic), where probands had psychosis, were ascertained from the Maudsley Twin Register in London. Dimensions were defined as ordinal symptom scores using the OPCRIT checklist, based on previous factor analyses of this and other samples. To qualify as a potentially useful phenotype, dimensions had to show (a) a satisfactory polychoric model fit and significant within-pair correlation in MZ pairs concordant for DSM-III-R psychosis and (b) that they could not be better defined in terms of other combinations of relevant symptoms, single symptoms, or dichotomized dimension scores. Relationships between dimension scores in twin probands and risk of psychosis in co-twins were also investigated. None of the positive or negative dimensions satisfied the phenotypic criteria. The disorganized dimensions showed significant and substantial correlations which maximized for a narrow definition. Combined negative/disorganized dimensions also showed significant and substantial correlations, but did not have advantages over disorganized dimensions. None of the dimensions were significant predictors of psychosis risk in co-twins. We conclude that, of the dimensions analyzed, the narrow disorganized dimension shows most promise as a phenotype for molecular genetic research.

Correlation and familial aggregation of dimensions of psychosis in affected sibling pairs from China

BACKGROUND

A number of studies with conflicting results have examined the familiality of schizophrenia syndromes in Western populations.

AIMS

The objective of this study was to determine, using clinical data from concordant sibling pairs, whether symptom dimensions and other clinical characteristics of schizophrenia show familial aggregation and are therefore potentially useful traits in genetic studies.

METHOD

We measured clinical and demographic features, and symptom dimensions of schizophrenia in 137 families from China who had two or more affected members with schizophrenia. Within-sibling pair correlation was assessed with intraclass correlation coefficient and kappa statistics.

RESULTS

Global functioning, positive, disorganisation and dysphoric symptoms, premorbid schizotypal and schizoid traits, premorbid social adjustment, type and age at illness onset all showed significant evidence of familial aggregation. DSM-IV schizophrenia subtypes were also found to be familial.

CONCLUSIONS

This is the first study in a large non-European population to confirm that schizophrenia dimensions and clinical characteristics show significant familiality, implying possible heritability. This supports their use in the delineation of homogeneous subsets for future genetic studies.

Positive family history is associated with persistent elevated emotional distress in schizophrenia: evidence from a 16-month follow-up study

There is some evidence that emotional reactivity to daily life stress is related to a genetic or familial liability to develop schizophrenia. However, it is unclear whether the emotional distress is elevated in schizophrenia patients with positive compared to negative family history. The aim of the study was to test the hypothesis that a persistent higher level of emotional distress in schizophrenia subjects is associated with a positive family history of schizophrenia. This study used the Talbieh Brief Distress Inventory (TBDI), the Positive and Negative Syndrome Scale (PANSS; including dysphoric mood, positive and negative subscales), Montgomery-Asberg Depression Rating Scale (MADRS), and the Distress Scale for Adverse Symptoms (DSAS) to investigate the difference in the magnitude of emotional distress scores between schizophrenia subjects with and without a positive family history of schizophrenia over time. Data were recorded for 69 multiplex family and 79 singleton patients at admission and about 16 months thereafter. No between-group differences were obtained in PANSS and DSAS scores. With regard to the TBDI: (a) both group of patients had no significant differences in emotional distress scores at admission; (b) patients with negative family history reported improvement in distress severity and depression severity (MADRS) 16 months after admission, while those with positive family history experienced persistent elevated emotional distress, mainly, on obsessiveness, and depression subscales; and (c) both groups of patients are characterized by elevated emotional distress at follow-up examination compared to healthy subjects. Thus, it appears that there is a strong association between positive family history and persistent elevated emotional distress. Because patients with positive and negative family history are likely to differ in genetic risk, our results suggest that long-term elevated levels of emotional distress may be related to a familial (environmental)/genetic vulnerability to schizophrenia.

The significance of family history in first-episode schizophrenia spectrum disorder

There have been inconsistent findings regarding the significance of family history of schizophrenia spectrum disorders in relation to presentation and course of illness. There has been little research relevant to this issue from first-episode patients. We examined the differences in premorbid adjustment, symptoms, and intellectual functioning between 28 first-episode schizophrenia spectrum patients with a history of such illness in first degree relatives and 28 matched patients without such a family history. The results indicate that whereas the 2 groups did not differ in presenting symptoms, those with a positive family history showed poorer intellectual functioning and less reduction in symptoms at 2 and 3 year follow-up and greater likelihood of abnormal electroencephalogram findings. The findings provide evidence that presence of a positive family history in first-episode patients is associated with a more pernicious form of illness.