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Several studies of the effects on cognition of selective serotonin reuptake inhibitors (SSRI), administered either acutely or sub-chronically in healthy volunteers, have found changes in learning and reinforcement outcomes. In contrast, to our knowledge, there have been no studies of chronic effects of escitalopram on cognition in healthy volunteers. This is important in view of its clinical use in major depressive disorder (MDD) and obsessive-compulsive disorder (OCD). Consequently, we aimed to investigate the chronic effect of the SSRI, escitalopram, on measures of ‘cold’ cognition (including inhibition, cognitive flexibility, memory) and ‘hot cognition’ including decision-making and particularly reinforcement learning. The study, conducted at the University of Copenhagen between May 2020 and October 2021, used a double-blind placebo-controlled design with 66 healthy volunteers, semi-randomised to receive either 20 mg of escitalopram (n = 32) or placebo (n = 34), balanced for age, sex and intelligence quotient (IQ) for at least 21 days. Questionnaires, neuropsychological tests and serum escitalopram measures were taken. We analysed group differences on the cognitive measures using linear regression models as well as innovative hierarchical Bayesian modelling of the Probabilistic Reversal Learning (PRL) task. The novel and important finding was that escitalopram reduced reinforcement sensitivity compared to placebo on both the Sequential Model-Based/Model-Free task and the PRL task. We found no other significant group differences on ‘cold’ or ‘hot’ cognition. These findings demonstrate that serotonin reuptake inhibition is involved in reinforcement learning in healthy individuals. Lower reinforcement sensitivity in response to chronic SSRI administration may reflect the ‘blunting’ effect often reported by patients with MDD treated with SSRIs. Trial Registration: NCT04239339.

Developmental prosopagnosia (DP)—or ‘face blindness’—refers to life-long problems with facial recognition in the absence of brain injury. We know that neurodevelopmental disorders tend to co-occur, and this study aims to explore if individuals with self-reported DP also report indications of other neurodevelopmental disorders, deficits, or conditions (developmental comorbidity). In total, 115 individuals with self-reported DP participated in this online cross-sectional survey. Face recognition impairment was measured with a validated self-report instrument. Indications of difficulties with navigation, math, reading, or spelling were measured with a tailored questionnaire using items from published sources. Additional diagnoses were measured with direct questions. We also included open-ended questions about cognitive strengths and difficulties. Results: Overall, 57% reported at minimum one developmental comorbidity of interest, with most reflecting specific cognitive impairment (e.g., in memory or object recognition) rather than diagnostic categories (e.g., ADHD, dyslexia). Interestingly, many participants reported cognitive skills or strengths within the same domains that others reported impairment, indicating a diverse pattern of cognitive strengths and difficulties in this sample. The frequency and diversity of self-reported developmental comorbidity suggests that face recognition could be important to consider in future investigations of neurodevelopmental comorbidity patterns.

Objective: Developmental prosopagnosia (DP) - or ‘face blindness’- is a severe deficit in face recognition that occurs in people with no known brain injury. While we know that other neurodevelopmental disorders commonly co-occur, there are to date no studies of the possible co-occurrence of DP or face recognition impairment with other neurodevelopmental disorders (excluding Autism Spectrum Disorder). The present work aimed to explore if individuals with self-reported DP report indications of other neurodevelopmental disorders, deficits, or conditions, collectively referred to as developmental comorbidity. Methods: 115 individuals with self-reported DP participated in this cross-sectional survey conducted online. Prosopagnosia was measured with the 20-item prosopagnosia index (Shah, Gaule, Sowden, Bird & Cook, 2015). Indications of difficulties with navigation, math, reading or spelling were measured with a tailored questionnaire, which also included open-ended questions about cognitive abilities and impairments. In addition to quantitative analysis of the questionnaire items, a qualitative descriptive approach was used to analyse the participants’ own descriptions of their difficulties and abilities. Results: The quantitative analysis revealed that 57 % of the participants reported at least one developmental comorbidity of interest, and these included aphantasia, memory problems, synaesthesia, dyslexia, dyscalculia, attention-deficit/hyperactivity disorder, and object agnosia. An exploratory factor analysis suggested four factors, ‘Developmental Prosopagnosia Symptoms’, ‘Navigation and Orientation’, ‘History of Reading/Spelling Difficulty’ and ‘History of Difficulties with Math’. The presence of developmental comorbidity was not associated with subjectively more severe DP. 25 % of the sample rated their navigation ability on level with clinically relevant complaints. The participants’ elaborations on their difficulties and abilities provided additional insights