Automated extraction of speech and turn-taking parameters in autism allows for diagnostic classification using a multivariable prediction model.

Autism spectrum disorder (ASD) is diagnosed on the basis of speech and communication differences, amongst other symptoms. Since conversations are essential for building connections with others, it is important to understand the exact nature of differences between autistic and non-autistic verbal behaviour and evaluate the potential of these differences for diagnostics. In this study, we recorded dyadic conversations and used automated extraction of speech and interactional turn-taking features of 54 non-autistic and 26 autistic participants. The extracted speech and turn-taking parameters showed high potential as a diagnostic marker. A linear support vector machine was able to predict the dyad type with 76.2% balanced accuracy (sensitivity: 73.8%, specificity: 78.6%), suggesting that digitally assisted diagnostics could significantly enhance the current clinical diagnostic process due to their objectivity and scalability. In group comparisons on the individual and dyadic level, we found that autistic interaction partners talked slower and in a more monotonous manner than non-autistic interaction partners and that mixed dyads consisting of an autistic and a non-autistic participant had increased periods of silence, and the intensity, i.e. loudness, of their speech was more synchronous.

Classification of first-episode psychosis using cortical thickness: A large multicenter MRI study.

Machine learning classifications of first-episode psychosis (FEP) using neuroimaging have predominantly analyzed brain volumes. Some studies examined cortical thickness, but most of them have used parcellation approaches with data from single sites, which limits claims of generalizability. To address these limitations, we conducted a large-scale, multi-site analysis of cortical thickness comparing parcellations and vertex-wise approaches. By leveraging the multi-site nature of the study, we further investigated how different demographical and site-dependent variables affected predictions. Finally, we assessed relationships between predictions and clinical variables. 428 subjects (147 females, mean age 27.14) with FEP and 448 (230 females, mean age 27.06) healthy controls were enrolled in 8 centers by the ClassiFEP group. All subjects underwent a structural MRI and were clinically assessed. Cortical thickness parcellation (68 areas) and full cortical maps (20,484 vertices) were extracted. Linear Support Vector Machine was used for classification within a repeated nested cross-validation framework. Vertex-wise thickness maps outperformed parcellation-based methods with a balanced accuracy of 66.2% and an Area Under the Curve of 72%. By stratifying our sample for MRI scanner, we increased generalizability across sites. Temporal brain areas resulted as the most influential in the classification. The predictive decision scores significantly correlated with age at onset, duration of treatment, and positive symptoms. In conclusion, although far from the threshold of clinical relevance, temporal cortical thickness proved to classify between FEP subjects and healthy individuals. The assessment of site-dependent variables permitted an increase in the across-site generalizability, thus attempting to address an important machine learning limitation.

Identification of voxel-based texture abnormalities as new biomarkers for schizophrenia and major depressive patients using layer-wise relevance propagation on deep learning decisions.

Non-segmented MRI brain images are used for the identification of new Magnetic Resonance Imaging (MRI) biomarkers able to differentiate between schizophrenic patients (SCZ), major depressive patients (MD) and healthy controls (HC). Brain texture measures such as entropy and contrast, capturing the neighboring variation of MRI voxel intensities, were computed and fed into deep learning technique for group classification. Layer-wise relevance was applied for the localization of the classification results. Texture feature map of non-segmented brain MRI scans were extracted from 141 SCZ, 103 MD and 238 HC. The gray level co-occurrence matrix (GLCM) was calculated on a voxel-by-voxel basis in a cube of voxels. Deep learning tested if texture feature map could predict diagnostic group membership of three classes under a binary classification (SCZ vs. HC, MD vs. HC, SCZ vs. MD). The method was applied in a repeated nested cross-validation scheme and cross-validated feature selection. The regions with the highest relevance (positive/negative) are presented. The method was applied on non-segmented images reducing the computation complexity and the error associated with segmentation process.

Effect of childhood physical abuse on social anxiety is mediated via reduced frontal lobe and amygdala-hippocampus complex volume in adult clinical high-risk subjects.

BACKGROUND: Childhood adverse experiences (CAE) are associated with clinical psychiatric disorders and symptoms, and with volumetric abnormalities in the amygdala-hippocampus complex (AmHiC) and frontal lobe (FroL) in adulthood. AIM: To study whether CAE are associated with reduced AmHiC and FroL and whether these structures mediate the effect of CAE on social anxiety and depression. METHOD: In seven European centres, 374 patients with recent onset of psychosis (n = 127), clinical high-risk to psychosis (n = 119) or recent onset of depression (n = 128) were scanned with MRI and their FroL and AmHiC volumes were measured. They all completed self-report scales for assessment of CAE, social anxiety and depression. RESULTS: Of the CAE domains, physical abuse was associated specifically with reduced grey and white matter volumes of FroL and AmHiC in psychotic and high-risk patients. After controlling intracranial volume, PhyAb associated significantly with FroL and its grey matter volume in high-risk patients only. In mediation analyses, the effect of physical abuse on social anxiety was mediated via reduced FroL grey mater volume in high-risk patients. In them, when the effects of AmHiC and depression were controlled, the effect of physical abuse on social anxiety was mediated via FroL grey matter volume reduction. CONCLUSIONS: Childhood physical abuse is associated with reduced frontal lobe and amygdala-hippocampus complex volume in adult subjects with psychotic symptoms. Reduced frontal lobe and amygdala-hippocampus complex volume mediate the effect of physical abuse on social anxiety in high-risk patients. The effect of physical abuse on depression-independent social anxiety is mediated via reduced frontal lobe.

[Early recognition and prevention of schizophrenia and other psychoses]. / Früherkennung und Prävention von Schizophrenie und anderen Psychosen.

The last two decades of clinical research have clearly demonstrated the comprehensive benefits of the early recognition and treatment of psychotic disorders. The attenuated and transient positive symptoms according to the ultrahigh risk criteria and the basic symptom criterion "Cognitive disturbances" are the main approaches for an indicated prevention. They have recently been recommended as criteria for a clinical high-risk (CHR) state of psychosis by the European Psychiatric Association (EPA) and, following these, in the German S3 guidelines for the treatment of schizophrenia by the German Association for Psychiatry, Psychotherapy and Psychosomatics (DGPPN); however, the efficacy of early treatment of patients with a CHR for psychoses critically depends on the development of prognostic instruments, which enable healthcare professionals to reliably identify these patients based on the individual objective risk profiles. An important goal is the treatment of functional deficits, which can be identified by an individual risk profile. The treatment of existing comorbid mental disorders, psychosocial problems and the prevention of potential future disorders also characterizes the recommendations of the EPA and DGPPN for early treatment, which favor psychotherapeutic, especially cognitive behavioral interventions over pharmacological treatment. The close interdisciplinary cross-sectoral cooperation between the disciplines of child and adolescent psychiatry, and adult psychiatry is of outstanding importance in this context.

Prefrontal gray matter volume mediates genetic risks for obesity.

Genetic and neuroimaging research has identified neurobiological correlates of obesity. However, evidence for an integrated model of genetic risk and brain structural alterations in the pathophysiology of obesity is still absent. Here we investigated the relationship between polygenic risk for obesity, gray matter structure and body mass index (BMI) by the use of univariate and multivariate analyses in two large, independent cohorts (n=330 and n=347). Higher BMI and higher polygenic risk for obesity were significantly associated with medial prefrontal gray matter decrease, and prefrontal gray matter was further shown to significantly mediate the effect of polygenic risk for obesity on BMI in both samples. Building on this, the successful individualized prediction of BMI by means of multivariate pattern classification algorithms trained on whole-brain imaging data and external validations in the second cohort points to potential clinical applications of this imaging trait marker.

Structural brain changes are associated with response of negative symptoms to prefrontal repetitive transcranial magnetic stimulation in patients with schizophrenia.

Impaired neural plasticity may be a core pathophysiological process underlying the symptomatology of schizophrenia. Plasticity-enhancing interventions, including repetitive transcranial magnetic stimulation (rTMS), may improve difficult-to-treat symptoms; however, efficacy in large clinical trials appears limited. The high variability of rTMS-related treatment response may be related to a comparably large variation in the ability to generate plastic neural changes. The aim of the present study was to determine whether negative symptom improvement in schizophrenia patients receiving rTMS to the left dorsolateral prefrontal cortex (DLPFC) was related to rTMS-related brain volume changes. A total of 73 schizophrenia patients with predominant negative symptoms were randomized to an active (n=34) or sham (n=39) 10-Hz rTMS intervention applied 5 days per week for 3 weeks to the left DLPFC. Local brain volume changes measured by deformation-based morphometry were correlated with changes in negative symptom severity using a repeated-measures analysis of covariance design. Volume gains in the left hippocampal, parahippocampal and precuneal cortices predicted negative symptom improvement in the active rTMS group (all r⩽-0.441, all P⩽0.009), but not the sham rTMS group (all r⩽0.211, all P⩾0.198). Further analyses comparing negative symptom responders (⩾20% improvement) and non-responders supported the primary analysis, again only in the active rTMS group (F(9, 207)=2.72, P=0.005, partial η 2=0.106). Heterogeneity in clinical response of negative symptoms in schizophrenia to prefrontal high-frequency rTMS may be related to variability in capacity for structural plasticity, particularly in the left hippocampal region and the precuneus.

[Neuroimaging in psychiatry: multivariate analysis techniques for diagnosis and prognosis]. / Neuroimaging in der Psychiatrie : Multivariate Analysetechniken zur Diagnostik und Verlaufsprädiktion.

BACKGROUND: Multiple studies successfully applied multivariate analysis to neuroimaging data demonstrating the potential utility of neuroimaging for clinical diagnostic and prognostic purposes. OBJECTIVES: Summary of the current state of research regarding the application of neuroimaging in the field of psychiatry. MATERIAL AND METHODS: Literature review of current studies. RESULTS: Results of current studies indicate the potential application of neuroimaging data across various diagnoses, such as depression, schizophrenia, bipolar disorder and dementia. Potential applications include disease classification, differential diagnosis and prediction of disease course. CONCLUSION: The results of the studies are heterogeneous although some studies report promising findings. Further multicentre studies are needed with clearly specified patient populations to systematically investigate the potential utility of neuroimaging for the clinical routine.

Reduced parahippocampal cortical thickness in subjects at ultra-high risk for psychosis.

BACKGROUND: Grey matter volume and cortical thickness represent two complementary aspects of brain structure. Several studies have described reductions in grey matter volume in people at ultra-high risk (UHR) of psychosis; however, little is known about cortical thickness in this group. The aim of the present study was to investigate cortical thickness alterations in UHR subjects and compare individuals who subsequently did and did not develop psychosis. METHOD: We examined magnetic resonance imaging data collected at four different scanning sites. The UHR subjects were followed up for at least 2 years. Subsequent to scanning, 50 UHR subjects developed psychosis and 117 did not. Cortical thickness was examined in regions previously identified as sites of neuroanatomical alterations in UHR subjects, using voxel-based cortical thickness. RESULTS: At baseline UHR subjects, compared with controls, showed reduced cortical thickness in the right parahippocampal gyrus (p < 0.05, familywise error corrected). There were no significant differences in cortical thickness between the UHR subjects who later developed psychosis and those who did not. CONCLUSIONS: These data suggest that UHR symptomatology is characterized by alterations in the thickness of the medial temporal cortex. We did not find evidence that the later progression to psychosis was linked to additional alterations in cortical thickness, although we cannot exclude the possibility that the study lacked sufficient power to detect such differences.

[Personalised medicine in psychiatry and psychotherapy. A review of the current state-of-the-art in the biomarker-based early recognition of psychoses]. / Personalisierte Medizin in der Psychiatrie und Psychotherapie. Ein Überblick über mögliche Biomarker-gestützte Methoden zur Früherkennung von Psychosen.

The main goal of psychiatric high-risk research--the personalised early recognition and intervention of schizophrenic and affective psychoses--is one of the biggest challenges of current clinical psychiatry due to the immense socioeconomic burden of these disorders. In this regard, this review discusses the prospects and caveats of new clinical, neuropsychological, neurophysiological and imaging-based concepts aimed at optimising the current state-of-the-art of early recognition. Finally, multivariate modelling and machine learning methods are presented as a novel methodological framework facilitating the decoding of early psychosis into different intermediate phenotypes. In the future, these phenotypes could be employed for a more objective risk stratification that operates at the single-subject level. This could allow us to generate clinically applicable prognostic biomarkers for these disorders that would propel the individualised prevention of disease transition, chronification and psychopharmacological treatment resistance of psychotic disorders.

[Prediction of psychosis by stepwise multilevel assessment--the Basel FePsy (Early Recognition of Psychosis)-Project]. / Vorhersage von Psychosen durch stufenweise Mehrebenenabklärung--Das Basler FePsy(Früherkennung von Psychosen)-Projekt.

BACKGROUND: We have conducted various studies in Basel with the aim of improving the methods for the early detection of psychosis (Früherkennung von Psychosen, FePsy). METHODS: From 1.3.2000 to 29.2.2004 234 individuals were screened using the Basel Screening Instrument for Psychosis (BSIP). 106 patients were identified as at risk for psychosis; out of these 53 remained in follow-up for up to 7 years (mean 5.4 years). The assessments were done with a specifically developed instrument for history taking, various scales for the psychopathology, assessments of neuropsychology and fine motor functioning, clinical and quantitative EEG, MRI of the brain, laboratory etc. RESULTS: Based on the BSIP alone, a relatively reliable prediction was possible: 21 (39.6%) of the individuals identified as at risk developed psychosis within the follow-up time. Post-hoc prediction could be improved to 81% by weighting psychopathology and including neuropsychology. Including the other domains obviously allows further improvements of prediction. CONCLUSIONS: The risk for psychosis should be assessed in a stepwise procedure. In a first step, a clinically oriented screening should be conducted. If an at-risk status is found, further assessments in various domains should be done in a specialised centre.

Amygdala reduction in patients with ADHD compared with major depression and healthy volunteers.

OBJECTIVE: Results in adult attention deficit hyperactivity disorder (ADHD) on structural brain changes and the clinical relevance are contradictory. The aim of this study was to investigate whether in adult patients with ADHD hippocampal or amygdala volumes differs from that in healthy controls and patients with major depression (MD). METHOD: Twenty patients with ADHD, 20 matched patients with MD and 20 healthy controls were studied with high resolution magnetic resonance imaging. RESULTS: Amygdala volumes in patients with ADHD were bilaterally smaller than in patients with MD and healthy controls. In ADHD, more hyperactivity and less inattention were associated with smaller right amygdala volumes, and more symptoms of depression with larger amygdala volumes. CONCLUSION: This study supports findings that the amygdala plays an important role in the systemic brain pathophysiology of ADHD. Whether patients with ADHD and larger amygdala volumes are more vulnerable to affective disorders needs further investigation.

Cerebral network deficits in post-acute catatonic schizophrenic patients measured by fMRI.

Twelve patients with catatonic schizophrenia and 12 matched healthy controls were examined with functional MRI while performing a motor task. The aim of our study was to identify the intracerebral pathophysiological correlates of motor symptoms in catatonic patients. The motor task included three conditions: a self-initiated (SI), an externally triggered (ET) and a rest condition. Statistical analysis was performed with SPM5. During the self-initiated movements patients showed significantly less activation than healthy controls in the supplementary motor area (SMA), the prefrontal and parietal cortex. Our results suggest a dysfunction of the "medial motor system" in catatonic patients. Self-initiated and externally triggered movements are mediated by different motor loops. The "medial loop" includes the SMA, thalamus and basal ganglia, and is necessary for self-initiated movements. The "lateral loop" includes parts of the cerebellum, lateral premotor cortex, thalamus and parietal association areas. It is involved in the execution of externally triggered movements. Our findings are in agreement with earlier behavioral data, which show deficits in self-initiated movements in catatonic patients but no impairment of externally triggered movements.

Reduced gray matter brain volumes are associated with variants of the serotonin transporter gene in major depression.

The serotonergic system is involved in the pathophysiology of major depression as well as in the early central nervous system development and adult neuroplasticity. The aim of the study was to examine in 77 patients with major depression and 77 healthy controls the association between the triallelic polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and gray matter (GM) brain volumes measured with 1.5 T magnetic resonance imaging. Voxel-based morphometry were estimated on magnetic resonance images and genotyping was performed. We found that healthy controls have a strong association between the 5-HTTLPR and GM volumes of the dorsolateral prefrontal cortex, left anterior gyrus cinguli, left amygdala as well as right hippocampus, whereas there is no such association in patients with major depression. Healthy subjects carrying the S- or L(G)-allele have smaller GM volumes than those with the L(A)-allele, indicating that 5-HTTLPR contributes to the development of brain structures. Patients with depression show reduced GM volumes, particularly when they are homozygous for the L(A)-allele, suggesting that these patients are more vulnerable for morphological changes during depressive episodes.

Structural brain alterations at different stages of schizophrenia: a voxel-based morphometric study.

Structural alterations in schizophrenia have mainly been regarded as the result of neurodevelopmental processes. However, it remains unresolved whether the pattern of morphological brain changes differs between different stages of disease. We examined structural brain changes in 93 first-episode (FES) and 72 recurrently ill (REZ) patients with schizophrenia (SZ) and 175 matched healthy control subjects (HC) using cross-sectional and conjunctional voxel-based morphometry (VBM) of whole-brain MRI data in a three-step approach. We found significant grey matter density (GMD) reductions in FES compared to HC bilaterally in the temporal and prefrontal areas, including the anterior cingulate gyrus, as well as in both thalami. Hippocampus and amygdala were affected on the left side (P<0.05, corrected). In REZ patients this pattern was spatially extended. The basal ganglia were exclusively reduced in the recurrently ill group compared to controls. Common to both disease groups were reductions in the bilateral perisylvian regions, the opercular region, the insula, prefrontal cortex, left inferior temporal gyrus, limbic system including hippocampus and amygdala, and the thalami. In FES patients there were no regions affected that were not also affected in REZ patients. In contrast, REZ patients showed extended alterations within the frontal and temporal regions, the hippocampus, amygdala and exclusively in the basal ganglia relative to the FES patients. Our findings suggest a system-specific involvement of neuronal networks in schizophrenia. Furthermore, our data suggest that in the advanced stages of schizophrenia additional cortical and subcortical brain areas become involved in the disease process. Longitudinal data will be required to further test this hypothesis.

5-HT1A receptor gene C -1019 G polymorphism and amygdala volume in borderline personality disorder.

Alterations of amygdala structure and function have been repeatedly described in patients with borderline personality disorder (BPD). The aim of our study was to determine whether a functional polymorphism of the 5-hydroxytryptamine(1A) receptor (5-HTR(1A)) gene C -1019 G (identity number: rs6295 G/C) is associated with structural changes of the amygdala in patients with BPD. Twenty-five right-handed female inpatients with BPD according to DSM IV and 25 healthy controls matched for age, sex, handedness and educational status were enrolled. Brain volumetry of the amygdala was performed with a 1.5-T Magnetom Vision apparatus (Siemens, Erlangen, Germany) and analyzed by the software program 'BRAINS'. Patients who have the 5-HTR(1A) gene G allele had significantly smaller amygdala volumes than C/C genotype carriers (P = 0.02). While no difference of allelic distribution between patients and controls was detected, the described effect of 5-HTR(1A) genotype on amygdala volume was found for the whole group of patients, as well as in the subgroup of patients with comorbid major depression (P = 0.004) but not in controls. In contrast to these subgroups of BPD patients who had significant amygdala volume differences, the mean amygdala volume of the whole group of BPD patients was not significantly different from that of controls. In summary, our study provides first evidence that 5-HTR(1A) gene C -1019 G polymorphism is associated with structural changes in the limbic system of BPD patients, a finding that might be disease related and might contribute to explanation of previous discrepant results regarding amygdala volume changes in BPD. Future research is recommended to clarify possible interactions between this functional polymorphism and symptoms, course and treatment responses in this disorder.

Structural brain alterations in subjects at high-risk of psychosis: a voxel-based morphometric study.

Forty Untreated high-risk (HR) individuals for psychosis and 75 healthy control subjects (HC) matched for age, gender, handedness and educational level were investigated by structural MRI. HR subjects were recruited at the Early Detection and Intervention Centre for Mental Crises (FETZ) of the Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Germany. Measurements of gray matter volumes were performed by voxel-based morphometry using SPM5. The sample of HR subjects showed GM volume reductions in frontal, lateral temporal and medial temporal regions compared to the healthy control group. These regions are compatible with structural findings in the clinically apparent disease of schizophrenia.

Cerebral changes and cognitive dysfunctions in medication-free schizophrenia - an fMRI study.

Proposing cognitive impairment in working memory (wm) functions as a cognitive core deficit in schizophrenia, 23 first episode, medication-free schizophrenic patients in a comparison of healthy adults have been investigated by fMRI. Additionally, the effects of different attentional demands in wm tasks were analysed. A wm paradigm was applied, in which stimuli were presented in a 2-back and a 0-back condition in a non-degraded and degraded version. As hypothesized in healthy controls increased activity during both 2-back tasks was found in the ventrolateral prefrontal cortex (VLPFC), dorsolateral prefrontal cortex (DLPFC), parietal regions, the thalamus and the cerebellum. Different activation patterns were found for the cingulate cortex in the 2-back degraded conditions. The comparison between healthy controls and schizophrenic patients revealed decreased activity in the right VLPFC in patients as well as increased activity in temporal regions. Furthermore patients' task performance quality was significantly lower for 2-back conditions. Schizophrenic patients use different cognitive strategies to solve working memory tasks, reflected in significantly altered cerebral activity. However, the different fMRI working memory correlates found in schizophrenic patients seem to be insufficient in terms of overall task performance.

Cerebral differences in explicit and implicit emotional processing--an fMRI study.

The processing of emotional facial expression is a major part of social communication and understanding. In addition to explicit processing, facial expressions are also processed rapidly and automatically in the absence of explicit awareness. We investigated 12 healthy subjects by presenting them with an implicit and explicit emotional paradigm. The subjects reacted significantly faster in implicit than in explicit trials but did not differ in their error ratio. For the implicit condition increased signals were observed in particular in the thalami, the hippocampi, the frontal inferior gyri and the right middle temporal region. The analysis of the explicit condition showed increased blood-oxygen-level-dependent signals especially in the caudate nucleus, the cingulum and the right prefrontal cortex. The direct comparison of these 2 different processes revealed increased activity for explicit trials in the inferior, superior and middle frontal gyri, the middle cingulum and left parietal regions. Additional signal increases were detected in occipital regions, the cerebellum, and the right angular and lingual gyrus. Our data partially confirm the hypothesis of different neural substrates for the processing of implicit and explicit emotional stimuli.