Cannabis-Induced Persistent Perceptual Disturbances: A Clinical Characterization Study of Multimodal Sensory Symptoms in 13 Patients

Cannabis use has been associated with persistent perceptual disturbances, but systematic clinical characterization remains limited, particularly regarding multimodal sensory involvement. To characterize persistent perceptual disturbances following cannabis use, focusing on symptom profiles, temporal patterns, and clinical features. This exploratory observational study was conducted across the Valle d'Aosta and Piemonte regions of Italy between 2020 and 2025. We characterized 13 patients with persistent visual/auditory symptoms following cannabis exposure through comprehensive clinical assessment, neurological examination, neuroimaging, and standardized questionnaires. Given the small sample size, analysis focused on clinical characterization rather than statistical inference. Thirteen patients (10 males, mean age 24.3 ± 4.1 years) had used natural cannabis (69.2%) or synthetic cannabinoids (30.8%). Visual snow was universal (100%), with high rates of trailing phenomena (92.3%), halos (84.6%), and color changes (76.9%). A novel finding was the presence of auditory hypersensitivity in 61.5% of patients. Symptoms emerged at a mean of 3.2 ± 2.4 weeks following cannabis cessation. All neurological investigations were normal. Comorbid anxiety disorders were present in 84.6% of patients; functional impairment was severe in 30.8%, moderate in 46.2%, and mild in 23.1%. This exploratory study describes persistent multimodal sensory disturbances in patients after cannabis exposure. Consistent visual snow, frequent auditory hypersensitivity, and normal neurological investigations suggest a distinct phenotype warranting systematic investigation. While preliminary and requiring validation in larger samples, these findings highlight a potentially underrecognized cannabis complication meriting clinical attention.