Cortical structures and their clinical correlates in antipsychotic-naïve schizophrenia patients before and after 6 weeks of dopamine D2/3 receptor antagonist treatment

BACKGROUND

Schizophrenia has been associated with changes in both cortical thickness and surface area, but antipsychotic exposure, illness progression and substance use may confound observations. In antipsychotic-naïve schizophrenia patients, we investigated cortical thickness and surface area as well as mean curvature before and after monotherapy with amisulpride, a relatively selective dopamine D2/3 receptor antagonist.

METHODS

Fifty-six patients and 59 matched healthy controls (HCs) underwent T1-weighted 3T magnetic resonance imaging. Forty-one patients and 51 HCs were re-scanned. FreeSurfer-processed baseline, follow-up values and symmetrized percentage changes (SPC) in cortical structures were analysed using univariate analysis of variance. Clinical measures comprised psychopathology ratings, assessment of functioning and tests of premorbid and current intelligence. We applied false discovery rate correction to account for multiple comparisons.

RESULTS

At baseline, groups did not differ in cortical thickness or surface area; however, curvature in the left hemisphere was higher in patients (p = 0.015). In both patients and HCs, higher curvature was associated with lower premorbid (p = 0.009) and current intelligence (p 0.43). Cortical thickness SPC was negatively associated with symptom improvement (p = 0.002).

CONCLUSIONS

Schizophrenia appears associated with subtle, yet clinically relevant aberrations in cortical structures. Mean curvature holds promise as a sensitive supplement to cortical thickness and surface area to detect complex structural brain abnormalities.

Attenuated mismatch negativity in patients with first-episode antipsychotic-naive schizophrenia using a source-resolved method

BACKGROUND

Mismatch negativity (MMN) is a measure of pre-attentive auditory information processing related to change detection. Traditional scalp-level EEG methods consistently find attenuated MMN in patients with chronic but not first-episode schizophrenia. In the current paper, we use a source-resolved method to assess MMN and hypothesize that more subtle changes can be identified with this analysis method.

METHOD

Fifty-six first-episode antipsychotic-naïve schizophrenia (FEANS) patients (31 males, 25 females, mean age 24.6) and 64 matched controls (37 males, 27 females, mean age 24.8) were assessed for duration-, frequency- and combined-type MMN and P3a as well as 4 clinical, 3 cognitive and 3 psychopathological measures. To evaluate and correlate MMN at source-level, independent component analysis (ICA) was applied to the continuous EEG data to derive equivalent current dipoles which were clustered into 19 clusters based on cortical location.

RESULTS

No scalp channel group MMN or P3a amplitude differences were found. Of the localized clusters, several were in or near brain areas previously suggested to be involved in the MMN response, including frontal and anterior cingulate cortices and superior temporal and inferior frontal gyri. For duration deviants, MMN was attenuated at the right superior temporal gyrus in patients compared to healthy controls (p = 0.01), as was P3a at the superior frontal cortex (p = 0.01). No individual patient correlations with clinical, cognitive, or psychopathological measures survived correction for multiple comparisons.

CONCLUSION

Attenuated source-localized MMN and P3a peak contributions can be identified in FEANS patients using a method based on independent component analysis (ICA). This indicates that deficits in pre-attentive auditory information processing are present at this early stage of schizophrenia and are not the result of disease chronicity or medication. This is to our knowledge the first study on FEANS patients using this more detailed method.

Hyper- and Hypomentalizing in Patients with First-Episode Schizophrenia: fMRI and Behavioral Studies

BACKGROUND

Historically, research investigating neural correlates of mentalizing deficits in schizophrenia has focused on patients who have been ill for several years with lengthy exposure to medication. Little is known about the neural and behavioral presentations of theory-of-mind deficits in schizophrenia, shortly after the first episode of psychosis.

METHODS

We investigated social cognition in 17 recently diagnosed first-episode schizophrenia (FES) patients with little or no exposure to antipsychotic medication and 1:1 matched healthy controls. We recorded behavioral and neural responses to the Animated Triangles Task (ATT), which is a nonverbal validated mentalizing task that measures the ascription of intentionality to the movements of objects.

RESULTS

FES patients under-interpreted social cues and over-interpreted nonsocial cues. These effects were influenced by current intelligence (IQ). Control group and FES neural responses replicated earlier findings in healthy adults. However, a region of anterior medial prefrontal cortex (amPFC) of FES patients showed a different response pattern to that of controls. Unlike healthy controls, patients increased activity in this social cognition region while studying "random" movements of shapes, as compared to the study of movements normally interpreted as "intentional".

CONCLUSIONS

Mentalizing deficits in FES consists of hypo- and hypermentalizing. The neural pattern of FES patients is consistent with deficits in the ability to switch off mentalizing processes in potentially social contexts, instead increasing them when intentionality is not forthcoming. Overall, results demonstrate complexities of theory of mind deficits in schizophrenia that should be considered when offering social cognitive training programs.

Heritability of cerebral glutamate levels and their association with schizophrenia spectrum disorders: a 1[H]-spectroscopy twin study

Research findings implicate cerebral glutamate in the pathophysiology of schizophrenia, including genetic studies reporting associations with glutamatergic neurotransmission. The extent to which aberrant glutamate levels can be explained by genetic factors is unknown, and if glutamate can serve as a marker of genetic susceptibility for schizophrenia remains to be established. We investigated the heritability of cerebral glutamate levels and whether a potential association with schizophrenia spectrum disorders could be explained by genetic factors. Twenty-three monozygotic (MZ) and 20 dizygotic (DZ) proband pairs con- or discordant for schizophrenia spectrum disorders, along with healthy control pairs (MZ = 28, DZ = 18) were recruited via the National Danish Twin Register and the Psychiatric Central Register (17 additional twins were scanned without their siblings). Glutamate levels in the left thalamus and the anterior cingulate cortex (ACC) were measured using 1[H]-magnetic resonance spectroscopy at 3 Tesla and analyzed by structural equation modeling. Glutamate levels in the left thalamus were heritable and positively correlated with liability for schizophrenia spectrum disorders (phenotypic correlation, 0.16, [0.02-0.29]; p = 0.010). The correlation was explained by common genes influencing both the levels of glutamate and liability for schizophrenia spectrum disorders. In the ACC, glutamate and glx levels were heritable, but not correlated to disease liability. Increases in thalamic glutamate levels found in schizophrenia spectrum disorders are explained by genetic influences related to the disease, and as such the measure could be a potential marker of genetic susceptibility, useful in early detection and stratification of patients with psychosis.

Alterations of Intrinsic Connectivity Networks in Antipsychotic-Naïve First-Episode Schizophrenia

BACKGROUND

The investigation of large-scale intrinsic connectivity networks in antipsychotic-naïve first-episode schizophrenia increases our understanding of system-level cerebral dysfunction in schizophrenia while enabling control of confounding effects of medication and disease progression. Reports on functional connectivity in antipsychotic-naïve patients have been mixed and the relation between network alterations, psychopathology and cognition is unclear.

METHODS

A total number of 47 patients with first-episode schizophrenia who had never received antipsychotic medication and 47 healthy controls were scanned with functional magnetic resonance imaging under resting conditions. Main outcome measures were differences in functional connectivity between groups and the relationship between network alterations, psychopathology and cognition.

RESULTS

Altered connectivity was found between right central executive network (CEN) and right ventral attention network (VAN) (patients > controls, P = .001), left CEN and left VAN (P = .002), and between posterior default mode network and auditory network (P = .006). Association between network connectivity and clinical characteristics was found as interactions between the effects of group and sustained attention (P = .005) and between group and processing speed (P = .007) on the connectivity between right CEN and right VAN.

CONCLUSIONS

Our findings suggest that the early phase of schizophrenia is characterized by increased connectivity between fronto-parietal networks suggested to be involved in the control of cognitive and sensory functions. Moreover, the present study suggests that the problem of not disengaging the VAN leads to difficulties with attention and possibly subjective awareness.

Patterns of Cortical Structures and Cognition in Antipsychotic-Naïve Patients With First-Episode Schizophrenia: A Partial Least Squares Correlation Analysis

BACKGROUND

Schizophrenia is associated with alterations in cortical structures and cognitive impairments, but antipsychotic medication may affect these measures. We investigated patterns of relationships between cortical structures and cognitive domains in antipsychotic-naïve patients with first-episode schizophrenia.

METHODS

T1-weighted 3T magnetic resonance imaging was performed in 105 patients and 136 healthy control subjects. Using FreeSurfer, we obtained measurements of cortical thickness, surface area, and mean curvature. Using an extensive neurocognitive battery including the Danish Adult Reading Test and subtests from the Cambridge Neuropsychological Test Automated Battery, we obtained estimates of premorbid intelligence, spatial working memory, spatial planning, intra-extradimensional set shifting, and reaction and movement times. With univariate analyses, we tested group differences between cortical structures and cognition. With partial least squares correlation analyses, we investigated patterns of associations between cortical structures and cognition.

RESULTS

Patients had significantly higher mean curvature and were impaired on 7 of 11 cognitive parameters. The between-group partial least squares correlation analysis revealed two cortical thickness/cognition patterns that differentiated patients and healthy control subjects (omnibus test, p = .011). Most cortical regions contributed reliably to these patterns. In patients, spatial working memory, spatial planning, reaction and movement times, and premorbid intelligence contributed reliably to the pattern; in healthy control subjects, spatial planning and intra-extradimensional set shifting contributed reliably.

CONCLUSIONS

Antipsychotic-naïve patients with first-episode schizophrenia displayed a higher mean curvature, but no significant difference in other gray matter indices was found. Nevertheless, the pattern of associations between global cortical thickness and cognitive functions was markedly different between groups. These multivariate analyses reveal a novel linkage between regional cortical brain structure and cognitive deficits at the earliest, never-medicated illness stage.

Delay Aversion and Executive Functioning in Adults With Attention-Deficit/Hyperactivity Disorder: Before and After Stimulant Treatment

BACKGROUND

Attention deficit hyperactivity disorder is a heterogeneous disorder, associated with deficits in motivation (e.g., delay aversion) and cognition. Methylphenidate is recommended as a first line treatment for attention deficit hyperactivity disorder symptoms, but little is known about its nonacute effects on motivational and cognitive deficits, particularly in adults with attention deficit hyperactivity disorder.

METHODS

We utilized a prospective, non-randomized, non-blinded, 6-week follow-up design with 42 initially stimulant medication-naïve adult patients with moderate to severe attention deficit hyperactivity disorder, and 42 age- and parental education-matched healthy controls. Delay aversion and executive functioning were assessed with 2 questionnaires and 5 performance-based tests.

RESULTS

At baseline, patients and controls differed significantly on performance-based measures (moderate to large effect sizes), and self-report of delay aversion and executive functioning (very large effect sizes). Treatment with methylphenidate medication (mean dose 65.54 mg/d, SD=10.39) was not associated with improvements in performance-based measures of delay aversion and executive functioning compared to controls, although improvements in self-report executive functioning and delay aversion were found. Self-reported delay aversion was most consistently associated with ADHD symptomatology at baseline and after medication.

CONCLUSION

Methylphenidate treatment does not have an effect on performance-based measures of delay aversion and executive functioning, but may have significant effects on self-reported delay aversion and executive functioning. The latter finding should be interpreted cautiously, given the subjective nature of these measures and design limitations. Self-reported delay aversion is most consistently associated with attention deficit hyperactivity disorder symptomatology.

Heritability of Schizophrenia and Schizophrenia Spectrum Based on the Nationwide Danish Twin Register

BACKGROUND

Twin studies have provided evidence that both genetic and environmental factors contribute to schizophrenia (SZ) risk. Heritability estimates of SZ in twin samples have varied methodologically. This study provides updated heritability estimates based on nationwide twin data and an improved statistical methodology.

METHODS

Combining two nationwide registers, the Danish Twin Register and the Danish Psychiatric Research Register, we identified a sample of twins born between 1951 and 2000 (N = 31,524 twin pairs). Twins were followed until June 1, 2011. Liability threshold models adjusting for censoring with inverse probability weighting were used to estimate probandwise concordance rates and heritability of the diagnoses of SZ and SZ spectrum disorders.

RESULTS

The probandwise concordance rate of SZ is 33% in monozygotic twins and 7% in dizygotic twins. We estimated the heritability of SZ to be 79%. When expanding illness outcome to include SZ spectrum disorders, the heritability estimate was almost similar (73%).

CONCLUSIONS

The key strength of this study is the application of a novel statistical method accounting for censoring in the follow-up period to a nationwide twin sample. The estimated 79% heritability of SZ is congruent with previous reports and indicates a substantial genetic risk. The high genetic risk also applies to a broader phenotype of SZ spectrum disorders. The low concordance rate of 33% in monozygotic twins demonstrates that illness vulnerability is not solely indicated by genetic factors.

Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder

BACKGROUND

Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use in schizophrenia. Based on the hypothesis that schizophrenia and ADHD represent a continuum of neurodevelopmental impairments, the aim was to identify overlapping and disease specific forms of impulsivity.

METHODS

Adolescents between 12 and 17 years of age were assessed with the Schedule for Affective Disorders and Schizophrenia for School-aged Children - Present and Lifetime Version. Subjects with early-onset, first-episode schizophrenia spectrum disorders (EOS) (N = 29) or ADHD (N = 29) and healthy controls (N = 45) were compared on two performance measures (Information Sampling Task, Stop Signal Task) and a subjective personality trait measure of impulsivity (Barratt Impulsiveness Scale, Version 11 (BIS-11)).

RESULTS

Significantly increased reflection impulsivity was observed in ADHD but not in the EOS group. No significant response inhibition deficits (stop signal reaction time) were found in the two clinical groups. The ADHD and the EOS group showed significantly increased motor, attentional, and non-planning subtraits of impulsivity.

CONCLUSIONS

Impaired pre-decisional information gathering appeared to be specific for ADHD while the information gathering was not significantly reduced in subjects with EOS. Neither the ADHD nor EOS group showed impaired response inhibition but shared increased personality subtraits of attentional, non-planning, and motor impulsivity although the latter was significantly more pronounced in ADHD. These increased subtraits of impulsivity may reflect diagnostic non-specific neurodevelopmental impairments in ADHD and EOS in adolescence.

Passive Double-Sensory Evoked Coherence Correlates with Long-Term Memory Capacity

HIGHLIGHTS Memory correlates with the difference between single and double-sensory evoked steady-state coherence in the gamma range (ΔC).The correlation is most pronounced for the anterior brain region (ΔC_A ).The correlation is not driven by birth size, education, speed of processing, or intelligence.The sensitivity of ΔC_A for detecting low memory capacity is 90%. Cerebral rhythmic activity and oscillations are important pathways of communication between cortical cell assemblies and may be key factors in memory. We asked whether memory performance is related to gamma coherence in a non-task sensory steady-state stimulation. We investigated 40 healthy males born in 1953 who were part of a Danish birth cohort study. Coherence was measured in the gamma range in response to a single-sensory visual stimulation (36 Hz) and a double-sensory combined audiovisual stimulation (auditive: 40 Hz; visual: 36 Hz). The individual difference in coherence (ΔC) between the bimodal and monomodal stimulation was calculated for each subject and used as the main explanatory variable. ΔC in total brain were significantly negatively correlated with long-term verbal recall. This correlation was pronounced for the anterior region. In addition, the correlation between ΔC and long-term memory was robust when controlling for working memory, as well as a wide range of potentially confounding factors, including intelligence, length of education, speed of processing, visual attention and executive function. Moreover, we found that the difference in anterior coherence (ΔC_A ) is a better predictor of memory than power in multivariate models. The sensitivity of ΔC_A for detecting low memory capacity is 92%. Finally, ΔC_A was also associated with other types of memory: verbal learning, visual recognition, and spatial memory, and these additional correlations were also robust enough to control for a range of potentially confounding factors. Thus, the ΔC is a predictor of memory performance may be useful in cognitive neuropsychological testing.

Pretreatment Cardiometabolic Status in Youth With Early-Onset Psychosis: Baseline Results From the TEA Trial

OBJECTIVE

To describe pretreatment cardiometabolic constitution in children and adolescents with first-episode psychosis (FEP).

METHODS

Baseline cardiometabolic assessment was performed in youths aged 12-17 years with FEP entering the Tolerability and Efficacy of Antipsychotics (TEA) trial and matched healthy controls. Patients were included between June 10, 2010, and January 29, 2014. ICD-10 was used as the diagnostic classification system. Cardiometabolic risk markers were compared between patients versus controls and antipsychotic-naive versus antipsychotic-exposed patients.

RESULTS

Comparing 113 youths with FEP (age ± SD = 15.74 ± 1.36 years, males = 30.1%, schizophrenia-spectrum disorders = 92.9%, antipsychotic-naive: n = 57) to 60 controls, patients had higher waist circumference (WC) z scores (1.13 ± 1.65 vs 0.42 ± 1.27, P = .018), cholesterol (4.10 ± 0.71 vs 3.79 ± 0.49 mmol/L, P = .014), low-density lipoproteins (2.37 ± 0.56 vs 2.13 ± 0.51, P = .012), and non-high-density lipoproteins (2.58 ± 1.60 vs 2.52 ± 0.52, P = .018). More patients than controls (42.9% vs 20.3%, P = .019) and antipsychotic-naive than antipsychotic-exposed (51.9% vs 34.0%, P = .023) had a WC > 90th percentile. Hypercholesterolemia (34.0% vs 12.5%, P = .015) was more frequent in patients, while decreased high-density lipoprotein cholesterol was more frequent in controls (32.5% vs 19.0%, P = .032). Family history of type 2 diabetes mellitus was associated with increased body mass index (BMI) z score (P < .001), WC z score (P = .001), insulin (P = .038), and homeostatic model assessment of insulin resistance (HOMA-IR; P = .025). Dyslipidemia was associated with significantly increased insulin (P = .041), HOMA-IR (P = .032), and low-density lipoprotein cholesterol (P = .041). Previous antipsychotic exposure was not associated with increased cardiometabolic risk. Early age at onset predicted increased BMI and WC z scores, while diagnosis of schizophrenia and higher Clinical Global Impression-Severity score were associated with increased blood lipids.

CONCLUSIONS

Youths with FEP had significantly greater WC and lipid abnormalities than matched controls, regardless of antipsychotic exposure. In youths with FEP, elevated metabolic risk predates antipsychotic exposure.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01119014; European Clinical Trials Database (EudraCT): 2009-016715-38​​​.

Testing a decades' old assumption: Are individuals with lower sensory gating indeed more easily distracted?

The sensory gating deficits in schizophrenia have been theorized to associate with increased distractibility. We explore the potential associations between sensory and sensorimotor gating and subjective and objective indices of distraction in healthy subjects. Forty healthy males were assessed with the P50 suppression and pre-pulse inhibition of the startle reflex (PPI) paradigms. Additionally, a neurocognitive test battery was administered in a cross-over design: with/without auditory distraction. Significant effects of distraction were found in response inhibition, and verbal working memory and attention. Parameters from the PPI and P50 suppression paradigms were significantly associated with the distractor effects on strategy formation, cognitive inhibition and flexibility, visual short-term memory, and the level of subjective distraction. Subjectively reported distraction was significantly associated with verbal working memory and attention as well as executive and supervisory processes. Sensory and sensorimotor gating efficiency do not reflect the effect of distraction across executive and attention functions i.e. we did not observe a generalized distractor effect. Gating only related to the effect of distraction on strategy formation, cognitive inhibition and flexibility, as well as visual short term memory. Future studies should investigate if gating deficits affect the distractibility of the same specific cognitive functions in patients with schizophrenia.

Quetiapine extended release versus aripiprazole in children and adolescents with first-episode psychosis: the multicentre, double-blind, randomised tolerability and efficacy of antipsychotics (TEA) trial

BACKGROUND

Head-to-head trials to guide antipsychotic treatment choices for paediatric psychosis are urgently needed because extrapolations from adult studies might not be implementable. In this superiority trial with two-sided significance testing, we aimed to compare the efficacy and safety of quetiapine-extended release (quetiapine-ER) versus aripiprazole in children and adolescents with first-episode psychosis, to determine whether differences between the two treatments were sufficient to guide clinicians in their choice of one drug over the other.

METHODS

In this multicentre, double-blind, randomised trial in seven Danish university clinics, we recruited children and adolescents aged 12-17 years with a diagnosis of ICD-10 schizophrenia-spectrum disorder, delusional disorder, or affective-spectrum psychotic disorder, and psychotic symptoms scoring at least 4 on at least one of the following Positive and Negative Syndrome Scale (PANSS) items: P1 (delusions), P2 (conceptual disorganisation), P3 (hallucinations), P5 (grandiosity), P6 (suspiciousness/persecution), and G9 (unusual thought content), and a total PANSS score greater than 60. Patients were randomly assigned (1:1) to 12 weeks of treatment with target doses of 600 mg/day of quetiapine-ER (starting from 50 mg/day) or 20 mg/day of aripiprazole (starting from 2·5 mg/day). The assigned drug was titrated over five levels, with 2 days at each dose, and the final dose achieved on day 9. Randomisation was done using a computer-generated concealed sequence with a block size of 8, and stratified by baseline PANSS positive score (≤20 points or >20 points) and age (12-14 years or 15-17 years). Study drugs were administered in identical capsules, and interventions, assessments, and data analysis were done masked. The primary outcome was PANSS positive score. Key adverse outcomes were bodyweight, homoeostatic model of insulin resistance (HOMA-IR), akathisia, and sedation. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01119014.

FINDINGS

Between June 10, 2010, and Jan 29, 2014, 231 participants were assessed for elegibility, of whom 113 were randomly assigned to quetiapine-ER (n=55) or aripiprazole (n=58). PANSS positive score did not differ between groups after 12 weeks (adjusted mean change -5·05 [5·46] for quetiapine-ER, -6·21 [5·42] for aripiprazole; p=0·98), but decreased over time in both groups (p<0·0001). Weight gain was more rapid with quetiapine-ER (p=0·0008), with an adjusted mean weight group difference at week 12 of 3·33 kg (SD 7·23; effect size 0·64; p<0·0001). The HOMA-IR group difference at week 12 favoured aripiprazole (adjusted mean log-transformed group difference 0·259 [SD 0·906]; effect size 0·35; p=0·0060). Akathisia was more common with aripiprazole at week 2 (observed in 34 [60%] of 57 patients; estimated 63·5%) than with quetiapine-ER (15 [30%] of 50; estimated 31·3%; p=0·0021), but not at other timepoints. Sedation proportions did not change significantly over time with either intervention (observed at weeks 2, 4, and 12, respectively, for quetiapine-ER in 43 [83%] of 52, 40 [83%] of 48, and 34 [72%] of 47 patients and for aripiprazole in 49 [89%] of 55, 52 [96%] of 54, and 44 [92%] of 48 patients), and the overall estimated probability combining all timepoints was significantly higher for aripiprazole (97·1%) than for quetiapine-ER (89·2%; p=0·012). In addition to sedation and akathisia, the most common adverse events were tremor (42 [79%] patients in the quetiapine-ER group vs 52 [91%] patients in the aripiprazole group), increased duration of sleep (47 [92%] vs 39 [71%]), orthostatic dizziness (42 [78%] vs 46 [81%]), depression (43 [80%] vs 44 [77%]), tension/inner unrest (37 [69%] vs 50 [88%]), failing memory (41 [76%] vs 44 [77%]), and weight gain (46 [87%] vs 38 [68%]).

INTERPRETATION

This first head-to-head comparison of quetiapine-ER versus aripiprazole in early-onset psychosis showed no significant group differences in severity of psychopathology after 12 weeks of treatment. Quetiapine-ER was associated with more metabolic adverse events and aripiprazole with more initial akathisia and, unexpectedly, more sedation. The limited antipsychotic efficacy and high level of adverse events were noticeable. This trial provides novel information for the treatment of early-onset psychosis and highlights the importance of adverse event profiles when choosing among antipsychotics for children and adolescents who often require chronic treatment.

FUNDING

The National Research Council for Health and Disease Foundation for Health Promotion, AP Møller Foundation, Rosalie Petersens Foundation, Stevn and Rindom Foundation, Foundation for the Promotion of Medical Science, The Capital Region Psychiatric Research Foundation, Tryg Foundation, Region of Southern Denmark Research Foundation, Danish Psychiatric Research Educational Fund, Psychiatry Foundation, Foundation of 17-12-1981, Psychiatric Research Foundation Region Zealand, Capital Region Strategic Research Foundation, Knud og Dagny Andresens Foundation, Psychiatric Research Foundation of 1967, The Capital Region Research Foundation, Dr Sofus Carl Emil Friis and Hustru Olga Friis Scholarship, Tømrerhandler Johannes Fogs Foundation, Brdr Hartmanns Foundation DKK, Aase and Ejnar Danielsens Foundation, Jacob Madsen and wife Olga Madsens Foundation, CC Klestrup and wife Scholarship, Lundbeck Foundation Scholarship, and Tømrermester Jørgen Holm and wife Elisas Scholarship.

No cognitive-enhancing effect of GLP-1 receptor agonism in antipsychotic-treated, obese patients with schizophrenia

OBJECTIVE

Schizophrenia is associated with profound cognitive and psychosocial impairments. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used for diabetes and obesity treatment, and animal studies have indicated cognitive-enhancing effects. In this investigator-initiated, double-blind, randomized, placebo-controlled trial, we tested non-metabolic effects of exenatide once-weekly (Bydureon™) in obese, antipsychotic-treated patients with schizohrenia spectrum disorder.

METHOD

Before and after 3 months of exenatide (N = 20) or placebo (N = 20) treatment, patients were assessed with the following: Brief Assessment of Cognition in Schizophrenia (BACS), Rey-Osterreith complex figure test (REY), Short-Form Health Survey (SF-36), Personal and Social Performance Scale (PSP) and the Positive and Negative Syndrome Scale (PANSS). We used BACS composite score as the main outcome measure.

RESULTS

Repeated measures analysis of variance on BACS composite score showed significant effect of 'Time' (P < 0.001), no effect of 'Group' (P = 0.64) and no 'Time*Group' interaction (P = 0.77). For REY, SF-36, PSP and PANSS, only significant 'Time' effects were found.

CONCLUSION

The non-significant results of this first clinical trial exploring non-metabolic effects of a long-acting GLP-1RA in patients with schizophrenia could reflect a general problem of translating cognitive-enhancing effects of GLP-1RAs from animals to humans or be explained by factors specifically related to schizophrenia spectrum patients with obesity such as antipsychotic treatment.

Is an Early Age at Illness Onset in Schizophrenia Associated With Increased Genetic Susceptibility? Analysis of Data From the Nationwide Danish Twin Register

Background

Early age at illness onset has been viewed as an important liability marker for schizophrenia, which may be associated with an increased genetic vulnerability. A twin approach can be valuable, because it allows for the investigation of specific illness markers in individuals with a shared genetic background.

Methods

We linked nationwide registers to identify a cohort of twin pairs born in Denmark from 1951 to 2000 (N = 31,524 pairs), where one or both twins had a diagnosis in the schizophrenia spectrum. We defined two groups consisting of; N = 788 twin pairs (affected with schizophrenia spectrum) and a subsample of N = 448 (affected with schizophrenia). Survival analysis was applied to investigate the effect of age at illness onset.

Findings

We found that early age at illness onset compared to later onset in the first diagnosed twin can be considered a major risk factor for developing schizophrenia in the second twin. Additionally, we found that the stronger genetic component in MZ twins compared to DZ twins is manifested in the proximity of assigned diagnosis within pairs.

Discussion

Early onset schizophrenia could be linked to a more severe genetic predisposition, indicating that age might be perceived as a clinical marker for genetic vulnerability for the illness.

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Early age at schizophrenia onset in one twin increases risk of illness in the second twin 4.7 times compared to a later onset.

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A stronger genetic predisposition may be needed to affect early schizophrenia onset in females compared to males.

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Genetic factors seem to play an important role in the proximity of assigned diagnosis within twin pairs.

The main aim of this study is to examine if early age at schizophrenia onset can be viewed as a clinical marker for increased genetic vulnerability in the illness. By linking the Danish Twin Register to other nationwide health registers we obtain accurate data regarding psychiatric diagnostic outcome in a complete twin population (> 31,000 twin pairs). Our study shows how an early age at illness onset in the first diagnosed twin in a pair is a major risk factor for developing schizophrenia in the second twin, underlining the importance of genetic factors in illness vulnerability.

Negative symptoms mediate the relationship between neurocognition and function in individuals at ultrahigh risk for psychosis

OBJECTIVE

Neurocognition is known to impact functioning in individuals at ultrahigh risk (UHR) for psychosis, but studies investigating potential mediators of this relationship are scarce. Building on evidence from schizophrenia spectrum disorders, the study tested whether negative symptoms and social skills act as mediators between neurocognition and functional outcome in UHR individuals.

METHODS

Ultrahigh risk participants (N = 84) underwent neurocognitive testing using the Brief Assessment of Cognition in Schizophrenia. Social skills and negative symptoms were assessed using the High-Risk Social Challenge task and the Scale for the Assessment of Negative Symptoms respectively. Four instruments were used to assess overall functioning, and one instrument assessed quality of life encompassing social functioning.

RESULTS

The cross-sectional analyses revealed that neurocognition was related to the measures of functioning. Negative symptoms mediated the relationship between neurocognition and four of the five measures of functioning. We did not find social skills to mediate between neurocognition and functioning.

CONCLUSION

Negative symptoms appear to mediate the relationship between neurocognition and functional outcome in UHR individuals, but the finding needs to be confirmed and extended to longitudinal studies. This underscores the importance of focusing on both neurocognition and negative symptoms when aiming at improving the functional outcome of UHR individuals.

Neurocognitive performance, subjective well-being, and psychosocial functioning after benzodiazepine withdrawal in patients with schizophrenia or bipolar disorder: a randomized clinical trial of add-on melatonin versus placebo

Chronic benzodiazepine use is common in patients with mental illness and is associated with cognitive impairment. It is unclear whether benzodiazepine-induced cognitive impairment is reversible. Amelioration of cognitive dysfunction may be facilitated during benzodiazepine tapering by add-on melatonin due to its anti-inflammatory and neuroprotective properties. We examined how melatonin and benzodiazepine withdrawal affect cognition, subjective well-being, and psychosocial functioning. Eighty patients with schizophrenia or bipolar disorder were randomized to add-on treatment once daily with either prolonged-release melatonin or placebo in a 24-week, double-blind clinical trial. All participants gradually tapered usual benzodiazepine dosage in a closely monitored treatment setting. We used the Brief Assessment of Cognition in Schizophrenia (BACS) to assess neurocognitive performance with additional assessments of subjective well-being and psychosocial functioning. BACS composite and subscale scores (except motor speed) significantly improved in parallel with benzodiazepine dose reduction, but there was no additional effect of melatonin. Cognitive performance was still markedly impaired post-tapering compared with normative data. Neither benzodiazepine withdrawal nor treatment group affected subjective well-being or psychosocial functioning. In conclusion, add-on melatonin does not seem to affect cognition, well-being, or psychosocial functioning in patients with severe mental illness. The observed improvement in cognitive performance could not be distinguished from retest effects, which may in turn have been facilitated by the benzodiazepine tapering.

Five years of specialised early intervention versus two years of specialised early intervention followed by three years of standard treatment for patients with a first episode psychosis: randomised, superiority, parallel group trial in Denmark (OPUS II)

OBJECTIVE

To compare the effects of five years of specialised early intervention (SEI) treatment for first episode schizophrenia spectrum disorder with the standard two years of SEI plus three years of treatment as usual.

DESIGN

Randomised, superiority, parallel group trial with blinded outcome assessment. Randomisation was centralised and computerised with concealed randomisation sequence carried out at an external site.

SETTING

Participants were recruited from six OPUS teams in Denmark between 2009 and 2012. OPUS teams provide SEI treatment to all patients diagnosed with a schizophrenia spectrum disorder in Denmark.

PARTICIPANTS

400 participants (51% women) with a mean age of 25.6 (standard deviation 4.3) were randomised to five years of SEI (experimental intervention; n=197) or to two years of SEI plus three years of treatment as usual (control; n=203).

INTERVENTIONS

OPUS treatment consists of three core elements-modified assertive community treatment, family involvement, and social skill training-with a patient-case manager ratio of no more than 12:1. For participants randomised to five years of OPUS treatment, the treatment was largely unchanged. Participants randomised to the control group were mostly referred to community health centres after two years of SEI treatment.

MAIN OUTCOMES

Follow-up assessments were conducted five years after start of OPUS treatment. Primary outcome was negative symptoms measured on the scale for assessment of negative symptoms (avolition-apathy, anhedonia, alogia, and affective blunting). Secondary outcomes were remission of both negative and psychotic symptoms, psychotic symptoms, suicidal ideation, substance abuse, compliance with medical treatment, adherence with treatment, client satisfaction, days in hospital care, and labour market affiliation.

RESULTS

Levels of negative symptoms did not differ between the intervention group and control group (1.72 v 1.81 points; estimated mean difference -0.10 (95% confidence interval -0.33 to 0.13), P=0.39). Participants receiving five years of OPUS treatment were more likely to remain in contact with specialised mental health services (90.4% v 55.6%, P<0.001), had higher client satisfaction (estimated mean difference 2.57 points (95% confidence interval 1.36 to 3.79), P<0.001), and had a stronger working alliance (estimated mean difference 5.56 points (95% confidence interval 2.30 to 8.82), P=0.001) than the control group.

CONCLUSIONS

This trial tests SEI treatment for up to five years for patients with first episode schizophrenia spectrum disorder; previous trials have found treatment effects for programmes lasting from one to three years. The prolonged SEI treatment had few effects, which could be due to the high level of treatment provided to control participants and the late start of specialised treatment.Trial registration Clinicaltrial.gov NCT00914238.

Mismatch negativity and P3a amplitude in young adolescents with first-episode psychosis: a comparison with ADHD

BACKGROUND

Deficient mismatch negativity (MMN) has been proposed as a candidate biomarker in schizophrenia and may therefore be potentially useful in early identification and intervention in early onset psychosis. In this study we explored whether deficits in the automatic orienting and reorienting responses, measured as MMN and P3a amplitude, are present in young adolescents with first-episode psychosis (FEP) and whether findings are specific to psychosis compared to young adolescents with attention deficit hyperactivity disorder (ADHD).

METHOD

MMN and P3a amplitude were assessed in young adolescents (age 12-17 years) with either FEP (N = 27) or ADHD (N = 28) and age- and gender-matched healthy controls (N = 43). The MMN paradigm consisted of a four-tone auditory oddball task with deviant stimuli based on frequency, duration and their combination.

RESULTS

Significantly less MMN was found in patients with psychosis compared to healthy controls in response to frequency and duration deviants. MMN amplitudes in the group of patients with ADHD were not significantly different from patients with psychosis or healthy controls. No significant group differences were found on P3a amplitude.

CONCLUSION

Young adolescents with FEP showed impaired MMN compared to healthy controls while intermediate and overlapping levels of MMN were observed in adolescents with ADHD. The findings suggest that young FEP patients already exhibit pre-attentive deficits that are characteristic of schizophrenia albeit expressed on a continuum shared with other neuropsychiatric disorders.

Cognitive Change during the Life Course and Leukocyte Telomere Length in Late Middle-Aged Men

Importance: Cognitive skills are known to decline through the lifespan with large individual differences. The molecular mechanisms for this decline are incompletely understood. Although leukocyte telomere length provides an index of cellular age that predicts the incidence of age-related diseases, it is unclear whether there is an association between cognitive decline and leukocyte telomere length.

Objective: To examine the association between changes in cognitive function during adult life and leukocyte telomere length after adjusting for confounding factors such as education, mental health and life style.

Design, Setting, and Participants: Two groups of men with negative (n = 97) and positive (n = 93) change in cognitive performance were selected from a birth cohort of 1985 Danish men born in 1953. Cognitive performance of each individual was assessed at age ~20 and 56 years. Leukocyte telomere length at age ~58 was measured using qPCR. Linear regression models were used to investigate the association between cognitive function and leukocyte telomere length.

Results: Men with negative change in cognitive performance during adult life had significantly shorter mean leukocyte telomere length than men with positive change in cognitive performance (unadjusted difference β = −0.09, 95% CI −0.16 to −0.02, p = 0.02). This association remained significant after adjusting for smoking, alcohol consumption, leisure time activity, body mass index (BMI) and cholesterol (adjusted difference β = −0.09, 95% CI −0.17 to −0.01, p = 0.02) but was non-significant after adjusting for smoking, alcohol consumption, leisure time activity, BMI, cholesterol, current cognitive function, depression and education (adjusted difference β = −0.07, 95% CI −0.16 to −0.01, p = 0.08).

Conclusion and Relevance: Preclinical cognitive changes may be associated with leukocyte telomere length.

The effect of positive symptoms on social cognition in first-episode schizophrenia is modified by the presence of negative symptoms

OBJECTIVE

There is considerable evidence that patients with schizophrenia have neurocognitive and social-cognitive deficits. It is unclear how such deficits in first-episode schizophrenia relate to current clinical symptoms.

METHOD

Fifty-nine patients with first-episode schizophrenia (FES) were tested using the Danish version of NART (premorbid IQ), subtests from WAIS-III (current IQ), and global cognition using Brief Assessment of Cognition in Schizophrena (BACS), a neurocognitive test battery. Social perception was tested using film clips of everyday interactions (TASIT). Theory of mind (ToM) was tested using silent animations (Animated Triangles Task). The FES subjects had been experiencing psychotic symptoms for several years (mean duration 9.5 years 95% confidence interval (CI [7.6;11.3]). The FES patients were divided into clinical subgroups based on their level of positive and negative symptoms (using SANS and SAPS). Healthy controls were matched to the patients.

RESULTS

High levels of negative symptoms were associated with low estimated functional IQ and poor neurocognition and social cognition. All SANS subscales, but Avolition-Apathy, had significant negative impact on social cognition. The effects of positive symptoms were complex. High levels of delusions were associated with higher premorbid IQ. In the presence of high levels of negative symptoms, high levels of positive symptoms were associated with the most comprehensive deficits in social perception, while, in the absence of negative symptoms, high levels of positive symptoms were not associated with such deficits.

CONCLUSION

The results suggest that social-cognitive training will need to take account of the above mentioned effects of symptoms. (PsycINFO Database Record

Are Weight Status and Cognition Associated? An Examination of Cognitive Development in Children and Adolescents with Anorexia Nervosa 1 Year after First Hospitalisation

Objective

The aim of this study was to characterise the association between the cognitive profile and weight restoration in children and adolescents with anorexia nervosa.

Methods

The study was a longitudinal, matched case–control, multicentre study. An assessment of cognitive functions was conducted by using the Wechsler Intelligence Scale for Children–III/the Wechsler Adult Intelligence Scale–III, the Test of Memory and Learning–second edition, Trail Making Tests A and B, the Rey–Osterrieth Complex Figure Test and the Cambridge Neuropsychological Test Automated Battery.

Results

One hundred twenty individuals, 60 patients with anorexia nervosa with mean age of 14.65 (SD 1.820) years and 60 healthy controls with mean age of 14.76 (SD 1.704) years, participated. No association was found between weight recovery and cognitive functions. However, a significant increase in motor speed was found in Trail Making Test A (p = 0.004), Reaction Time (RTI) five‐choice movement time (p = 0.002) and RTI simple movement time (p = 0.011), resulting in a normalisation corresponding to that found in healthy controls. Furthermore, a significantly lower score in the perceptual organization index (p = 0.029) was found at follow‐up.

Conclusions

Weight recovery appears not to be associated with cognition. Copyright © 2016 The Authors European Eating Disorders Review published by Eating Disorders Association and John Wiley & Sons Ltd