Neurodevelopmental Antecedents and Sensory Phenomena in Obsessive Compulsive Disorder: A Systematic Review Supporting a Phenomenological-Developmental Model

Background: The majority of models on obsessive compulsive disorder (OCD) endorse a top-down perspective on the cognitive mechanisms underlying OCD functioning and maintenance, whereas a bottom-up perspective is rarely pursued. Objectives: The aim of the study was to review the empirical literature on sensory phenomena (SP) and neurodevelopmental antecedents of OCD, which could support the conceptualization of an alternative, bottom-up perspective integrating neurodevelopmental and phenomenological levels of analysis on OCD. Methods: A systematic review according to PRISMA guidelines was performed in PubMed/MEDLINE, PsycInfo, the Cochrane Library, and Excerpta Medica Database (EMBASE) and focused on SP and "neurodevelopmental antecedents " (operationalized in early risk factors, neuroimaging signs, neurological soft signs, and sensory responsivity). The time interval was from inception up to March 31, 2022. Results: From the search in electronic databases, 48 studies were retained and reviewed. SP are highly prevalent in OCD patients and overrepresented in comparison with healthy controls. Similarly, OCD patients also present a higher prevalence of early environmental adversities and sensorimotor alterations in terms of neurological soft signs and sensory over-responsivity in the tactile and acoustic domains; additional findings included hypogyrification signs at neuroimaging. Both sensorimotor alterations and SP are associated with tic-related manifestations and poorer insight in OCD patients. Conclusions: On the ground of established common subjective experience of SP and premorbid neurodevelopmental features, we hypothesized an explanatory model for OCD, which considers the possible pathophysiological role for altered corollary discharge and enhanced error detection in the neurodevelopment of SP and obsessions. SP may represent the subjective experiential resonance of an individual history of persistently inaccurate sensory predictions, whereas accompanying manifestations, such as the obsessive need for order and symmetry, may represent a compensatory attempt to mitigate SP. This neurodevelopmental-phenomenological bottom-up model, describing a dimensional gradient of sensorimotor alterations and related subjective experiences, may contribute to explain the dimensional affinity between OCD and schizophrenia spectrum disorders. Furthermore, this model could be useful for the early detection of subjects at higher risk of OCD.