About breaking barriers, the risk paradox, and other twists

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Editorial Perspective: When is a ‘small effect’ actually large and impactful?

Reporting of effect sizes is standard practice in psychology and psychiatry research. However, interpretation of these effect sizes can be meaningless or misleading – in particular, the evaluation of specific effect sizes as ‘small’, ‘medium’ and ‘large’ can be inaccurate depending on the research context. A real-world example of this is research into the mental health of children and young people during the COVID-19 pandemic. Evidence suggests that clinicians and services are struggling with increased demand, yet population studies looking at the difference in mental health before and during the pandemic report effect sizes that are deemed ‘small’. In this short review, we utilise simulations to demonstrate that a relatively small shift in mean scores on mental health measures can indicate a large shift in the number of cases of anxiety and depression when scaled up to an entire population. This shows that ‘small’ effect sizes can in some contexts be large and impactful

Capturing brain‐cognition relationship: Integrating task‐based fMRI across tasks markedly boosts prediction and test‐retest reliability

Capturing individual differences in cognition is central to human neuroscience. Yet our ability to estimate cognitive abilities via brain MRI is still poor in both prediction and reliability. Our study tested if this inability can be improved by integrating MRI signals across the whole brain and across modalities, including task-based functional MRI (tfMRI) of different tasks along with other non-task MRI modalities, such as structural MRI, resting-state functional connectivity. Using the Human Connectome Project (n = 873, 473 females, after quality control), we directly compared predictive models comprising different sets of MRI modalities (e.g., seven tasks vs. non-task modalities). We applied two approaches to integrate multimodal MRI, stacked vs. flat models, and implemented 16 combinations of machine-learning algorithms. The stacked model integrating all modalities via stacking Elastic Net provided the best prediction (r = 0.57), relatively to other models tested, as well as excellent test-retest reliability (ICC=∼.85) in capturing general cognitive abilities. Importantly, compared to the stacked model integrating across non-task modalities (r = 0.27), the stacked model integrating tfMRI across tasks led to significantly higher prediction (r = 0.56) while still providing excellent test-retest reliability (ICC=∼.83). The stacked model integrating tfMRI across tasks was driven by frontal and parietal areas and by tasks that are cognition-related (working-memory, relational processing, and language). This result is consistent with the parieto-frontal integration theory of intelligence. Accordingly, our results contradict the recently popular notion that tfMRI is not reliable enough to capture individual differences in cognition. Instead, our study suggests that tfMRI, when used appropriately (i.e., by drawing information across the whole brain and across tasks and by integrating with other modalities), provides predictive and reliable sources of information for individual differences in cognitive abilities, more so than non-task modalities

Diagnostic efficiency of the SDQ for parents to identify ADHD in the UK:a ROC analysis

BackgroundEarly, accurate identification of ADHD would improve outcomes while avoiding unnecessary medication exposure for non-ADHD youths, but is challenging, especially in primary care.The aim of this paper is to test the Strengths and Difficulties Questionnaire (SDQ) using a nationally representative sample to develop scoring weights for clinical use. MethodThe British Child and Adolescent Mental Health Survey (N=18,232 youths 5 to 15 years old) included semi-structured interview DSM-IV diagnoses and parent-rated SDQ scores. ResultsAreas Under the Curve (AUCs) for SDQ subscales were good (0.81) to excellent (0.96) across sex and age groups. Hyperactive/Impulsive scores of 10+ increased odds of ADHD by 21.3x. For discriminating ADHD from other diagnoses, accuracy was fair (<0.70) to good (0.88); Hyperactive/Impulsive scores of 10+ increased odds of ADHD by 4.47x. ConclusionsThe SDQ is free, easy to score, and provides clinically meaningful changes in odds of ADHD that can guide clinical decision-making in an evidence based medicine framework

The temporal representation of experience in subjective mood

Humans refer to their mood state regularly in day-to-day as well as clinical interactions. Theoretical accounts suggest that when reporting on our mood we integrate over the history of our experiences; yet, the temporal structure of this integration remains unexamined. Here, we use a computational approach to quantitatively answer this question and show that early events exert a stronger influence on reported mood (a primacy weighting) compared to recent events. We show that a Primacy model accounts better for mood reports compared to a range of alternative temporal representations across random, consistent, or dynamic reward environments, different age groups, and in both healthy and depressed participants. Moreover, we find evidence for neural encoding of the Primacy, but not the Recency, model in frontal brain regions related to mood regulation. These findings hold implications for the timing of events in experimental or clinical settings and suggest new directions for individualized mood interventions

Dimensions and Latent Classes of Episodic Mania-Like Symptoms in Youth: An Empirical Enquiry

The dramatic increase in diagnostic rates of bipolar disorder in children and adolescents in the USA has led to an intense interest in the phenomenology of the disorder. Here we present data from a newly-developed instrument to assess episodic mania-like symptoms in youth in a large population-based sample (N = 5326) using parent- and self-report. We found that a substantial proportion of children screened positive for having episodes of “going high” and were at an increased risk for morbidity and impairment. Using factor analysis, we identified that episodic mania-like symptoms comprised two dimensions: An under-controlled dimension that was associated with significant impairment, and a low-risk exuberant dimension. Using latent class analysis, we identified a small group of children scoring high on a range of manic symptoms and suffering from severe psychosocial impairment and morbidity. Our results carry implications for the nosology and psychosocial impairment associated with episodic mood changes in young people

Ketamine Modulates the Neural Correlates of Reward Processing in Unmedicated Patients in Remission from Depression.

BACKGROUND: Ketamine as an antidepressant improves anhedonia as early as 2h post-infusion. These drug effects are thought to be exerted via actions on reward-related brain areas-yet, these actions remain largely unknown. Our study investigates ketamine's effects during the anticipation and receipt of an expected reward, after the psychotomimetic effects of ketamine have passed, when early antidepressant effects are reported. METHODS: We examined ketamine's effects during the anticipation and receipt of expected rewards on pre-defined brain areas, namely the dorsal and ventral striatum, the ventral tegmental area, the amygdala and the insula. We have recruited 37 male and female participants who remitted from depression and were free from symptoms and antidepressant treatments at the time of the scan. Participants were scanned, 2h after drug administration, in a double-blind cross over design (ketamine:0.5mg/kg and placebo) while performing a monetary reward task. RESULTS: A significant main effect of ketamine, across all ROIs, was observed during the anticipation and feedback phases of win and no-win trials. The drug effects were particularly prominent in the nucleus accumbens and putamen, which showed increased activation upon the receipt of smaller rewards compared to neutral. The levels of (2R,6R)-HNK, 2h post-infusion, significantly correlated with the activation observed in the ventral tegmental area for that contrast. CONCLUSIONS: These findings demonstrate that ketamine can produce detectable changes in reward-related brain areas, 2h after infusion, which occur without symptom changes and support the idea that ketamine might improve reward-related symptoms via modulation of response to feedback