Course of intelligence deficits in early onset, first episode schizophrenia: a controlled, 5-year longitudinal study

Neurocognitive and social cognitive impairments in remission and symptomatic states of early-onset schizophrenia spectrum disorders

Previous studies demonstrated neurocognitive impairments in early-onset schizophrenia (EOS) and other psychotic spectrum disorders (PSD). This study aimed to compare remitted and symptomatic cases in terms of neurocognition and theory of mind (ToM). 50 healthy controls (HC) and 106 patients diagnosed schizophrenia in remission (EOS-R, n = 38), symptomatic schizophrenia (EOS-S, n = 34), and other PSD (n = 34) were included in our study. The Positive and Negative Symptom Scale, Columbia-Suicide Severity Rating Scale, Reactive and Proactive Aggression Questionnaire were used to evaluate psychopathology. A cognitive battery was conducted to measure verbal learning/memory, visual learning/memory, executive functions (EF), inhibition, processing speed (PS), verbal fluency skills. Reading Mind in Eyes Test (RMET) and Faux-Pas tests were implemented to assess ToM. Principal Component Analysis was used to identify cognitive domain scores. Patient groups had poorer performance in cognitive domains than the HC group. The cognitive impairment and psychopathology levels of EOS-R and the PSD groups were comparable for all cognitive domains. The EOS-S group also had poorer scores in Rey verbal learning score (d = 0.87), RMET (d = 0.72), verbal fluency (d = 0.66), PS/EF (d = 0.82) and visual learning/memory (d = 0.83) test scores than the PSD group. Only RMET (d = 0.72) and executive function/processing speed domain (d = 0.63) were significantly impaired in the EOS-S group than the EOS-R group Cognitive impairments seen in remitted psychotic disorders were on the same continuum. Impaired EF/PS and ToM skills could be a cognitive marker for symptomatic illness in youth.

Intelligence quotient changes over 10 years: Diversity of cognitive profiles in first episode of psychosis and healthy controls

OBJECTIVE

This study aimed to analyse whether intelligence quotient (IQ) improves, declines, or remains stable over 10 years among FEP patients and healthy subjects.

METHODS

A group of FEP patients enrolled in a Program of First Episode Psychosis in Spain called PAFIP, and a sample of Healthy Controls (HC) completed the same neuropsychological battery at baseline and approximately 10 years later, which included the WAIS vocabulary subtest to estimate premorbid IQ and 10-year IQ. Cluster analysis was performed separately in the patient group and the HC group to determine their profiles of intellectual change.

RESULTS

One hundred and thirty-seven FEP patients were grouped into five clusters: "Improved low IQ" (9.49 % of patients), "Improved average IQ" (14.6 %), "Preserved low IQ" (17.52 %), "Preserved average IQ" (43.06 %), and "Preserved high IQ" (15.33 %). Ninety HC were grouped into three clusters: "Preserved low IQ" (32.22 % of the HC), "Preserved average IQ" (44.44 %), and "Preserved high IQ" (23.33 %). The first two clusters of FEP patients, characterized by a low IQ, earlier age at illness onset, and lower educational attainment, showed a substantial cognitive improvement. The remaining clusters demonstrated cognitive stability.

CONCLUSIONS

The FEP patients showed intellectual improvement or stability, but no decline post-onset of psychosis. However, their profiles of intellectual change are more heterogeneous than that of HC over 10 years. Particularly, there is a subgroup of FEP patients with a significant potential for long-term cognitive enhancement.

The Dutch Bipolar Offspring Study: Cognitive Development and Psychopathology

Various aspects of the relationship between cognitive impairment and bipolar disorder are not clear yet. This study examines cognitive and educational functioning prospectively in offspring at familial risk for bipolar disorder, in order to improve our understanding of the association between cognitive functioning and psychopathology. Bipolar offspring (N = 92) from the prospective Dutch bipolar offspring study were evaluated at adolescence and adulthood for IQ estimate, educational achievement and development of any psychiatric disorder. The main outcome was IQ estimate after 12 years of follow-up (offspring mean age 28 years). Generalized estimating equation (GEE) analyses showed that any lifetime DSM-IV axis I diagnosis was related to a lower cognitive outcome at adulthood as compared to unaffected bipolar offspring. No specific association was found for type of diagnosis. Early onset psychopathology (diagnosis at or before age 15 years) was significantly related to lower IQ estimate at adulthood, indicating a sensitive period for neurocognitive development.

Does the Fast Track Intervention Prevent Later Psychosis Symptoms?

The Fast Track (FT) intervention was a multimodal preventive intervention addressing antisocial development across 10 years of childhood and early adolescence. The intervention included parent management training, child social-cognitive skills training, peer coaching and mentoring, academic skills tutoring, and a classroom social-emotional learning program. While not specifically designed to target psychosis symptoms (e.g., social withdrawal, thought abnormalities), the present study aimed to examine whether the FT intervention prevented psychosis symptoms through childhood and adolescence and into adulthood. Participants included the FT intervention and high-risk control samples (N = 891; 69% male; M age = 6.58 years, SD = .48). Psychosis symptoms were assessed using the "thought problems" subscale of the parent-report Child Behavior Checklist during grades 1, 2, 4, 5, and 7, and the self-report Adult Behavior Checklist at age 25 years, in line with prior research using this measure. Growth models included the FT condition and covariates (i.e., initial risk screen score, cohort, socioeconomic status, rural/urban status, race, and sex) as predictors; and child, adolescent, and adult psychosis symptoms as outcomes. Intervention status was not significantly associated with the slope of psychosis symptoms; however, after controlling for concurrent cannabis use, intervention participants reported lower levels of psychosis symptoms over time. Findings suggest that interventions targeting antisocial behavior may prevent psychosis symptoms in the long term.

Do clinical characteristics predict the cognitive course in early-onset schizophrenia-spectrum disorders?

BACKGROUND

Being in a period with extensive brain maturation, adolescents with early-onset schizophrenia-spectrum disorders (EOS) provide unique neurodevelopmental data that may contribute to a better understanding of schizophrenia at all ages. Cognitive dysfunction is a central feature of schizophrenia and is more pronounced in EOS than in later onset illness. However, there is limited research on both the long-term course of global cognition in EOS, and how cognition over time is influenced by clinical characteristics during the early illness period.

METHODS

Thirty-one EOS patients and 73 controls (age 12-18) were assessed on clinical variables at baseline (PANSS, duration of untreated psychosis [DUP], hospitalizations, suicide attempts, and remission). Neuropsychological assessments with the MATRICS Consensus Cognitive Battery (MCCB) were conducted at baseline and after both 1 and 2 years, and composite scores of total performances were calculated. The analyses were performed with a linear mixed model.

RESULTS

The present study found that global cognition followed a stable course over the first years of the disease in EOS, though at a significantly lower level in EOS compared with the controls. We did not detect a relationship between DUP, remission, positive/negative symptoms, and hospitalizations on one hand, and long-term cognition on the other hand, but PANSS-general and suicide attempt history at baseline were identified as risk factors of longitudinal cognitive function.

CONCLUSIONS

Though at different levels, the EOS group and the controls had a similar cognitive course over 2 years. Some baseline characteristics (psychotic symptoms, DUP, remission, and hospitalization) had no influence on cognition within the first 2 years of illness. In contrast, general symptoms and a history of suicide attempts at baseline were more potent risk factors of the cognitive course than the psychotic-specific symptoms, and should, therefore, be subject to specific attention in the evaluation and treatment of patients with early-onset psychosis.

Secondary school teachers and mental health competence: Italy-United Kingdom comparison

AIM

The aim of this study was to evaluate the differences between teachers' knowledge about early psychosis among three different Italian cities and a UK sample.

METHODS

The sample consisted of 556 secondary school teachers from three different cities in Italy (Milan, Rome and Lamezia Terme) and London (UK). The research was based on the Knowledge and Experience of Social Emotional Difficulties Among Young People Questionnaire. The Italian version of the questionnaire was used in Italy.

RESULTS

Overall, 67.6% of English teachers, 58.5% of Milan's teachers, 41.8% of Rome's teachers and 33.3% of Lamezia Terme's teachers were able to recognize psychotic symptoms from a case vignette. Logistic regression analysis showed that 'city' was the only independent variable significantly related to the correct/wrong answer about diagnosis.

CONCLUSIONS

We found statistically significant differences between the three Italian samples and the UK sample regarding teachers' knowledge about first signs of psychosis. English teachers showed a better knowledge than Italian teachers in general. Teachers from Milan, where a specific early detection program was established in 2000, seemed to be more familiar with early signs of psychosis than teachers in the other two Italian towns.

Predictors of outcome in early-onset psychosis: a systematic review

Given the global burden of psychotic disorders, the identification of patients with early-onset psychosis (EOP; that is, onset before the age of 18) at higher risk of adverse outcome should be a priority. A systematic search of Pubmed, Embase, and PsycInfo (1980 through August 2014) was performed to identify longitudinal observational studies assessing correlates and/or predictors of clinical, functional, cognitive, and biological outcomes in EOP. Seventy-five studies were included in the review. Using multivariate models, the most replicated predictors of worse clinical, functional, cognitive, and biological outcomes in EOP were premorbid difficulties and symptom severity (especially of negative symptoms) at baseline. Longer duration of untreated psychosis (DUP) predicted worse clinical, functional, and cognitive outcomes. Higher risk of attempting suicide was predicted by greater severity of psychotic illness and of depressive symptoms at the first episode of psychosis. Age at onset and sex were not found to be relevant predictors of outcome in most multivariate models, whereas studies using bivariate analyses yielded inconsistent results. Lower intelligence quotient at baseline predicted lower insight at follow-up, worse functional outcomes, and a diagnostic outcome of schizophrenia. Biological predictors of outcome in EOP have been little studied and have not been replicated. Lower levels of antioxidants at baseline predicted greater brain volume changes and worse cognitive functioning at follow-up, whereas neuroimaging markers such as regional cortical thickness and gray matter volume at baseline predicted remission and better insight at follow-up, respectively. EOP patients with poorer premorbid adjustment and prominent negative symptoms at initial presentation are at risk of poor outcome. They should therefore be the target of careful monitoring and more intensive interventions to address whether the disease course can be modified in this especially severely affected group. Early intervention strategies to reduce DUP may also improve outcome in EOP.

Neurocognition in early-onset schizophrenia

Cognitive impairment is recognized as a central feature of schizophrenia. Early-onset schizophrenia (EOS) represents a more severe variant of the disorder associated with onset in childhood or adolescence. Examination of the cognitive abnormalities of EOS offers the opportunity to explore how disease-related mechanisms may affect facets of cognitive development. This article summarizes and synthesizes available data with regards to the profile of cognitive impairments in EOS, their severity, and their evolution over the course of the disorder.

IQ change over time in schizophrenia and healthy individuals: a meta-analysis

BACKGROUND

Cognitive deficits have been recognized as a key feature of schizophrenia, since the first description by Kraepelin. Specifically, lower intelligence is considered a core feature of the disorder and may represent a risk factor for its development. However, whether global intelligence decreases over time in schizophrenia is not known. The aims of this quantitative meta-analysis are to gather, integrate and estimate the overall mean effect size of IQ change over time in schizophrenia as compared to healthy individuals.

METHODS

A systematic search was conducted to identify relevant studies. Longitudinal studies with at least two intelligence assessments in schizophrenia cohorts were retrieved. Studies had to report sufficient data on IQ-change and include data from healthy comparisons for computation of effect sizes. For each study, the Cohen d was calculated as well as a combined mean effect size.

RESULTS

Fourteen studies were identified. Eight studies with a total of 280 patients and 306 healthy controls were suitable to be included. The mean weighted baseline IQ was 97.20 for patients and 109.26 for controls. The mean weighted IQ-change per year was +0.33 for patients and +2.08 for controls. The combined effect size was Cohen's d = -0.48, p = 0.01.

CONCLUSIONS

A global cognitive deficit is present in patients with schizophrenia expressed as a lower test score increase over repeated testing as compared to healthy subjects possibly due to the lack of practice effects in patients. Thus, schizophrenia is characterized by a relative lack of gain in global cognitive abilities over time.

Is there change in intelligence quotient in chronically ill schizophrenia patients? A longitudinal study in twins discordant for schizophrenia

BACKGROUND

Intellectual deficits are commonly found in schizophrenia patients. These intellectual deficits have been found to be heritable. However, whether the intellectual deficits change over time and, if so, whether the change is related with an increased genetic risk for the disease are not known.

METHOD

We investigated change of intelligence quotient (IQ) in a twin sample of chronically ill schizophrenia patients, the discordant co-twins and healthy controls during a follow-up period of 5 years. A total of 52 twins completed two IQ assessments: nine patients [three monozygotic (MZ) and six dizygotic (DZ)], 10 unaffected co-twins (three MZ and seven DZ) and 33 healthy control twins (21 MZ and 12 DZ).

RESULTS

A significant interaction effect over time was found between IQ measurement and illness (F=4.22, df=1, p<0.05), indicating that change in IQ over time is significantly different between the groups. A stable course in IQ over time was found in the patients with schizophrenia (mean IQ from 109.78 at baseline to 108.44 at follow-up) relative to both the healthy control twins who showed a small increase (from 114.61 at baseline to 119.18 at follow-up) (t=2.06, p<0.05) and the unaffected co-twins (from 111.60 to 117.60, t=-2.32, p<0.05). IQ change in the unaffected co-twins of schizophrenia patients was comparable with that in healthy control twins (t=-0.49, p=0.63).

CONCLUSIONS

Patients with schizophrenia in the chronic phase of the disease, but not the discordant co-twins, show a lack of increase in IQ, which is probably due to environmental (non-genetic) factors related to the disease.

The developmental course of executive functioning in schizophrenia

Executive dysfunction is a core feature of schizophrenia, but our understanding of the developmental course of this neuropsychological domain in the disease remains largely unexplored. A review of the research evidence points to a number of persistent debates about the course of executive functioning and its relation to illness course. A better understanding of the neurocognitive trajectories of executive functioning in schizophrenia could help identify the risk and modifying factors that influence the onset, severity and course of disease, and the chance to re-direct or re-shape that course and improve outcomes. To accomplish this requires assessment of the diverse and integrated nature of those abilities, and the changes over time in those abilities requires multiple instruments and techniques in order to improve the research methods and understanding of an important area of impairment in schizophrenia.

Deficient maturation of aspects of attention and executive functions in early onset schizophrenia

The few existing long-term, neuropsychological follow-up studies of early onset schizophrenia (EOS) patients have reported relative stability in some cognitive functions but abnormal developmental trajectories in verbal memory, set shifting, aspects of attention, and speed of information processing throughout late adolescence into early adulthood. The current 5-year follow-up study compared the development of specific cognitive functions in EOS patients (N = 17) from the time of first-episode to chronic phase with that of healthy controls (N = 38) and secondarily to patients with other early onset, non-organic, non-affective psychoses (EOP) (N = 11). Speed of processing of executive functions, set shifting, and attention improved significantly in the healthy controls and reflected continuous functional maturation during late adolescence and early adulthood. The developmental progression of attention and set shifting but not speed of processing of executive functions was significantly subnormal in EOS patients. Other specific cognitive functions that had attained functional maturity in the healthy controls before or around the time of the baseline assessment showed normal development in EOS patients during the follow-up period, indicating stable cognitive deficits. These results suggest post-onset developmental deficits in two out of the three aspects of attention and executive functions that have protracted maturational trajectories and that overlap the age of onset of EOS. No significant difference in the development of any specific cognitive function was found between the EOS and EOP group.