The meaning of significant mean group differences for biomarker discovery.

Over the past decade, biomarker discovery has become a key goal in psychiatry to aid in the more reliable diagnosis and prognosis of heterogeneous psychiatric conditions and the development of tailored therapies. Nevertheless, the prevailing statistical approach is still the mean group comparison between "cases" and "controls," which tends to ignore within-group variability. In this educational article, we used empirical data simulations to investigate how effect size, sample size, and the shape of distributions impact the interpretation of mean group differences for biomarker discovery. We then applied these statistical criteria to evaluate biomarker discovery in one area of psychiatric research-autism research. Across the most influential areas of autism research, effect size estimates ranged from small (d = 0.21, anatomical structure) to medium (d = 0.36 electrophysiology, d = 0.5, eye-tracking) to large (d = 1.1 theory of mind). We show that in normal distributions, this translates to approximately 45% to 63% of cases performing within 1 standard deviation (SD) of the typical range, i.e., they do not have a deficit/atypicality in a statistical sense. For a measure to have diagnostic utility as defined by 80% sensitivity and 80% specificity, Cohen's d of 1.66 is required, with still 40% of cases falling within 1 SD. However, in both normal and nonnormal distributions, 1 (skewness) or 2 (platykurtic, bimodal) biologically plausible subgroups may exist despite small or even nonsignificant mean group differences. This conclusion drastically contrasts the way mean group differences are frequently reported. Over 95% of studies omitted the "on average" when summarising their findings in their abstracts ("autistic people have deficits in X"), which can be misleading as it implies that the group-level difference applies to all individuals in that group. We outline practical approaches and steps for researchers to explore mean group comparisons for the discovery of stratification biomarkers.

Trends in Mental Health Presentations to a Paediatric Emergency Department.

Aims This study aimed to analyse trends in mental health presentations to the Emergency Department (ED), which anecdotally had increased over the past decade. Methods The ED's electronic 'Symphony' system was used to identify the annual number of presentations categorised as having a mental health complaint from 2006-2017. A detailed analysis was performed on presentations over a one-year period. Results The number of presentations increased from 69 in 2006 to a peak of 432 in 2016 (526% increase). The overall admission rate was 33.3%(n=99), while 52.5%(n=156) of presentations occurred outside of standard working hours. Similar increases were documented by other ED's worldwide, and the WHO estimate that neuropsychiatric disorders will become one of the top five causes of morbidity, mortality and disability among children by 2020. Conclusion With the number of mental health presentations dramatically increasing, carefully designed and integrated strategies are required to pro-actively tackle this growing epidemic.

Assessment of Cognitive Training & Social Interaction in People with Mild to Moderate Dementia: A Pilot Study.

Objectives: To evaluate the cognitive, neuropsychiatric, and quality of life outcomes of computer-based cognitive training and social interaction on people with mild to moderate dementia. Methods: Ten individuals with dementia were recruited to complete a cognitive training regimen. They were randomly assigned to a high social interaction (HSI) group (n = 5) and low social interaction (LSI) group (n = 5). Eight of the original 10 participants completed the cognitive training and were evaluated on cognitive abilities, neuropsychiatric symptoms (NPS), and quality of life (QoL). Results: Mean scores for the HSI group increased on cognitive assessments, where mean scores for the LSI group saw decline, or stability. There was an overall reduction in the frequency and severity of NPS presentation in both the HSI and LSI group. Mixed results were found for mean changes in QoL. Discussion: These results support the idea of social interaction influencing cognitive outcomes, cognitive training influencing NPS, and both social interaction and cognitive training influencing QoL. The findings illustrate the feasibility and importance of incorporating social activity to computerized cognitive training for people with dementia. Clinical Implications: Cognitive training that incorporates social interaction may be a promising intervention for individuals with dementia experiencing NPS.

[High Prevalence of Antipsychotic Medication Use in Dementia Patients in German Neuropsychiatric Practices]. / Hohe Prävalenz der Verwendung von Antipsychotika bei Demenzpatienten in deutschen neurologischen und psychiatrischen Praxen.

Background The aim of the present study was to examine inpatients as well as patients living at home with respect to the frequency of antipsychotic medication use and to determine the factors leading to initial use of antipsychotics following dementia diagnosis. Methods This study included patients aged 60 years and over with an initial diagnosis of all-cause dementia (index date) by German psychiatrists in Disease Analyzer database (IMS Health). The main outcome measure was the proportion of patients who initially received an antipsychotic prescription after the index date. Kaplan-Meier analyses were performed for studying time to initiation of antipsychotic therapy as a function of age and residence in nursing homes. A Cox proportional hazards regression model was used to estimate the relation between the likelihood of therapy initiation and the predefined demographical/clinical variables. Results 14 915 patients with dementia (mean age 80.3 years, 34.7 % male, 53.3 % residents of nursing homes) were included in this study. Within two years after the index date, 47.7 % patients with dementia were treated with antipsychotics. Residing in nursing homes, private insurance status, higher age, private health insurance, exhibiting mental disorders due to known physiological condition, personality and behavioral disorders due to known physiological condition, vascular dementia, and symptoms and signs involving emotional state were positively associated with therapy initiation. Conclusion The prevalence of antipsychotic drug therapy in dementia patients, particularly in nursing homes, is very high. Further studies including qualitative research are required in order to understand and explain the reasons for this prescribing behavior.

Fluid intelligence and executive functioning more alike than different?

OBJECTIVE: Fluid intelligence (Gf) has been related to executive functioning (EF) in previous studies, and it is also known to be correlated with crystallized intelligence (Gc). The present study includes representative measures of Gf, Gc, and EF frequently used in clinical practice to examine this Gf-EF relation. It is hypothesised that the Gf-EF relation is higher than the Gc-EF relation, and that working memory in particular (as a measure of EF) shows a high contribution to this relation. METHOD: Confirmatory factor analysis was performed on a mixed neuropsychiatric and non-clinical sample consisting of 188 participants, using the Kaufman Adolescent and Adult Intelligence Test, and three executive tasks of the Cambridge Neuropsychological Test Automated Battery, covering working memory, planning skills, and set shifting. RESULTS: The model fitted the data well [χ²(24)=35.25, p=0.07, RMSEA=0.050]. A very high correlation between Gf and EF was found (0.91), with working memory being the most profound indicator. A moderate to high correlation between Gc and EF was present. Current results are consistent with findings of a strong relation between Gf and working memory. CONCLUSION: Gf and EF are highly correlated. Gf dysfunction in neuropsychiatric patients warrants further EF examination and vice versa. It is discussed that results confirm the need to distinguish between specific versus general fluid/executive functioning, the latter being more involved when task complexity and novelty increase. This distinction can provide a more refined differential diagnosis and improve neuropsychiatric treatment indication.

Diagnostic Behavior for Mild Cognitive Impairment in General and Neuropsychiatric Practices in Germany.

Little is known about the diagnostic methods currently used in routine care for patients with mild cognitive impairment (PwMCI). We estimated the frequency of diagnostic procedures in incident PwMCI compared to incident patients with dementia (PwD) in 2016-2017. The study is based on the Disease Analyzer database. After matching by age and sex, 4,700 PwMCI and 4,700 PwD were available. The diagnostic procedures were identified on the basis of the related medical fee schedule items. All diagnostic procedures were used more frequently in PwMCI than in PwD. The drafting of a practice-oriented MCI guideline is an important task for the future.

Neurocognition in schizophrenia: a study of the productivity and visibility of Spanish authors.

This paper provides a map of the scientific productivity of authors affiliated to a Spanish institution and who have addressed one of the most important current topics in schizophrenia: The study of cognitive performance. A search of the Web of Science yielded 125 articles that met the inclusion criteria. In order to provide a comprehensive overview of scientific productivity, we examine several bibliometric indicators, concerning both productivity and impact or visibility. The analysis also focuses on qualitative aspects of key theoretical importance, such as the kinds of cognitive functions that are most often assessed and the tests most widely used to evaluate them in clinical practice. The study shows that interest in the subject of cognitive function in schizophrenia has increased considerably in Spain since the beginning of this century. The results also highlight the need to standardize the type of tests to be used in the cognitive assessment of patients with schizophrenia.

[Dementia - a relevant subject in psychiatric research?]. / Demenzerkrankungen - ein thema für die psychiatrische forschung?

OBJECTIVE: Demographic change calls for increased efforts in dementia research. METHODS: A systematic analysis of a German-speaking psychiatric journal was performed. RESULTS: 18.2 % of all papers published in were related to dementia and cognition. CONCLUSIONS: Dementia is a main issue; only papers regarding schizophrenia were more common. Health service research is largely lacking.

[Prescription differences of dementia drugs in urban and rural areas in Germany]. / Antidementivaverordnungen in Stadt und Land--Ein Vergleich zwischen Ballungszentren und Flächenstaaten in Deutschland.

OBJECTIVE: The objective of this study was to detect regional variability in anti-dementia drug prescriptions in metropolitan and rural regions of Germany in order to assess the widespread assumption that dementia treatment coverage is lower in rural areas because of the lower physician density in ambulatory care, especially for neuropsychiatrists. METHODS: We compared the 2007 prescription rates for Donepezil, Rivastigmine, Galantamine and Memantine in defined daily doses per capita in the population aged 65 and older insured in the German Statutory Health Insurance. The prescription data for the States of Berlin and Hamburg were compared with those in the adjacent rural-type States of Brandenburg and Lower Saxony. RESULTS: We found a greater proportion of both general practitioners and neuropsychiatrists prescribing dementia drugs and a higher population coverage with dementia drugs in the rural states compared to the urban states. CONCLUSIONS: The data suggest that the drug coverage in case of dementia is better in rural than in urban states in spite of a lower physician density. This unexpected result can be explained by the fact that a smaller proportion of physicians participate in the prescription of dementia drugs in urban areas, a phenomenon probably related to differences in task description and clientele selection between physicians in urban and rural areas.