It depends on how you define 'true story'. While it's not a verbatim account of one specific incident, it incorporates real-life research and issues related to concussions in sports, so in a sense, it has roots in truth.
Well, it's not straightforward. 'Concussion' might incorporate elements of real events, but it's likely that some aspects have been fictionalized or dramatized to make it more engaging for the audience.
Not entirely. While it draws some inspiration from true events, it also incorporates fictional aspects to create a more compelling cinematic narrative.