Speakers
 

Tatyana Branco Nunes

ABSTRACT:

Longitudinal Outcomes and Predictors of Ventral Capsule/Ventral Striatum Deep Brain Stimulation in Treatment-Refractory Obsessive–Compulsive Disorder

Deep brain stimulation (DBS) is a promising treatment for treatment-refractory obsessive–compulsive disorder (TR-OCD), but its long-term effects and clinical predictors of treatment response remain insufficiently understood. This study investigated acute and longitudinal outcomes of ventral capsule/ventral striatum (VC/VS) DBS and potential predictors of symptom improvement in 23 patients treated between 2014 and 2025. OCD severity was assessed using the Yale–Brown Obsessive Compulsive Scale (Y-BOCS) and analyzed using linear mixed-effects models. DBS significantly reduced Y-BOCS scores acutely (mean reduction: 8.8 points, 25.6%; p < 0.001; Cohen’s d = 1.09), with continued improvement averaging 0.31 points per month. Younger age and earlier OCD onset showed trends toward faster improvement, while trait anxiety was associated with greater overall symptom severity but not longitudinal improvement. After a mean follow-up of 40.5 months, nine patients were full responders, three partial responders, and seven non-responders. These findings support the sustained efficacy of VC/VS DBS while highlighting the need to better understand individual differences in long-term treatment outcomes.

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Aedan O’Shea 

ABSTRACT:

Circulating miRNA Signatures of Psilocybin and LSD in Healthy Humans
 
Psychedelics such as psilocybin and LSD show promise as transdiagnostic therapeutics, but their molecular mechanisms and potential biomarkers for patient stratification remain poorly understood. Within this CIN-funded project, we examined how psychedelic exposure alters microRNA (miRNA) expression in healthy volunteers across two cohorts. In the psilocybin study, miRNAs were sequenced from bulk plasma while in the LSD study, from neuron-derived extracellular vesicles (L1CAM+ exosomes). This presentation will exhibit which miRNAs change after dosing, which pathways they point to, and whether they could serve as candidate markers for stratifying patients.

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Amy Sylvester 

ABSTRACT:

Investigating catecholamine function in 22q11.2 copy number variants through the lens of neuromelanin-sensitive MRI
 
Disruption in catecholamine systems (dopamine and norepinephrine) is associated with several neuropsychiatric conditions, including schizophrenia, ADHD, and Parkinson's disease. The rare genetic conditions 22q11.2 deletion and duplication syndrome infer an increased risk of neuropsychiatric disorders, a phenomenon which may be linked to genetically-mediated disruption of catecholamine systems. When catecholamines are broken down, a paramagnetic compound called neuromelanin is deposited in the catecholamine producing brain areas - the substantia nigra and locus coeruleus. Neuromelanin accumulation in these areas can then be visualised using MRI, giving an indication of lifetime catecholamine function. By applying neuromelanin-sensitive MRI in 22q11.2 copy number variants, we found evidence of altered neuromelanin signal in both the locus coeruleus and substantia nigra, suggesting dysregulation of norepinephrine and dopamine.

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James Wilkinson

ABSTRACT:

Cognitive Effort and Reward Delay in Decision-Making: Valuation, Subjective Experience, and Neural Correlates

Many everyday decisions involve trade-offs between potential rewards and the cognitive effort and/or temporal delays associated with obtaining them. This research investigates how these costs influence decision-making, how they are represented in the brain, and how cognitive effort is subjectively experienced. First, an incentive-compatible behavioural experiment examines how cognitive effort and delay are integrated during monetary choices. The findings suggest that effort and delay contribute independently and approximately additively to subjective valuation, with immediate effort exerting a particularly strong influence on choice. Second, a fMRI study investigates the neural correlates of subjective value during decisions involving effort, delay, and their combination, examining how value-related brain activitation varies across decision contexts. Finally, a series of experimental studies investigates the phenomenology of cognitive effort across different cognitive tasks and difficulty levels, examining variations in subjective experiences including fatigue, engagement, interest, and irritability. Together, these studies aim to advance our understanding of how cognitive effort and temporal delay shape decisions, linking computational accounts of subjective valuation with their neural correlates and the subjective experience of effortful behaviour.