Project Type
Project Start Date
Project End Date
Target Population(s)
Individuals with Irritability after traumatic brain injury

The study focuses on the challenging problem of post-traumatic irritability (primary aim) and aggression (secondary aim). Irritability and Aggression are a high impact, pervasive, and under-studied problem that affects approximately 29-71% of individuals with traumatic brain injury (TBI). The current literature does not support Standards or Guidelines for the management of TBI irritability and aggression. The proposed research addresses this critical gap in the evidence-based treatment by producing new scientific knowledge that contributes to Standards of care in this area. The research study, based on positive results of a single site study, is a multi-center, parallel-group, randomized, double-blind, placebo-controlled trial of amantadine hydrochloride for the treatment of chronic TBI irritability and aggression. The study aims are: Aim 1: Assess effect of amantadine for 28 days at reducing TBI irritability. Aim 2: Assess the effect of amantadine for 28 days at reducing TBI aggression. Aim 3: Assess the effect of amantadine for 60 days on TBI irritability and aggression. Aim 4: Assess the effect of amantadine on cognitive function following TBI. Led by Carolinas Rehabilitation in Charlotte, North Carolina, the project is a collaborative research partnership with 5 other TBI rehabilitation research centers: University of Washington, The Institute for Rehabilitation and Research, The Ohio State University, Indiana University, and Spaulding Rehabilitation Hospital. The study sample will be 168 individuals with TBI injured at least 6 months prior to enrollment with moderate or severe irritability. The project is run through coordinated efforts of the project director, center leads, research staff, and an external data coordinating center at Columbia University.