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David Williamson

Integrated Traumatology Center, Hôpital du Sacré-Coeur de Montréal, Centre intégré universitaire de santé et de services sociaux du Nord-de-l'Île-de-Montréal, Montréal, Canada.

3 papers in the library · 14 citations · publishing 2024-2025

Papers

Pharmacological therapies for early and long-term recovery in disorders of consciousness: current knowledge and promising avenues.

Expert review of neurotherapeutics June 1, 2025 Rosalie Girard Pepin, Fatemeh Seyfzadeh, David Williamson et al. 7 citations

Pharmacological treatment options for disorders of consciousness (DoC), which range from coma to minimally conscious state, remain limited due to the heterogeneity of causes such as traumatic brain injury, stroke, and infections. A lack of rigorous clinical trials has led to off-label use of drugs—including dopaminergic and GABAergic agents, antidepressants, statins, and anticonvulsants—often without clear mechanistic understanding. Robust longitudinal trials are needed, prioritizing early subacute intervention and better-defined outcomes that consider immediate responses and long-term quality of life. A shift toward personalized medicine and unified functional frameworks is advocated, along with increased use of AI tools to predict treatment responses.

Psychometric properties of the 23-Item Clinician Administered Dissociative States Scale (CADSS) in a psychological trauma population.

Journal of affective disorders November 1, 2024 J Douglas Bremner, David Williamson, Viola Vaccarino 5 citations

Dissociative symptoms can arise from psychological trauma or as a side effect of certain medications, making accurate assessment important. The 23-item Clinician Administered Dissociative States Scale (CADSS) was evaluated in 276 participants: 148 with trauma history and PTSD, 100 with trauma history but no PTSD, and 28 healthy controls without trauma or psychiatric disorder. The scale showed high internal consistency (Cronbach's alpha 0.91) and a single-factor structure. Trauma-exposed participants with PTSD had higher CADSS scores than those without PTSD or without trauma. Veterans with combat-related PTSD showed increased scores after exposure to combat-related stimuli. The CADSS performs reliably for assessing dissociation in psychologically traumatized individuals.

The pattern of dissociative symptoms differs between post-traumatic stress disorder and first esketamine administration for treatment-resistant depression.

Journal of affective disorders June 12, 2025 David Williamson, Linda Williamson, Viola Vaccarino et al. 2 citations

Dissociative symptoms are common in many patients with PTSD and also appear during the first esketamine treatment for treatment-resistant depression. Comparing 134 PTSD patients and 759 TRD patients receiving their first esketamine dose, dissociative symptoms were more prevalent overall in the esketamine group. However, the pattern differed: PTSD patients more often reported dissociative amnesia and identity fragmentation, while esketamine patients most frequently experienced depersonalization and derealization. This distinct pattern suggests that the underlying causes of dissociative symptoms may differ between these conditions.