Traumatic events such as accidents, death of close people, difficult deliveries, important losses, etc., can be, in the case of isolated events, dealt with very quickly and effectively with the EMDR method. In my experience, the harmful effects (post-traumatic stress (PTSD)) can be resolved and prevented in very few sessions, as long as they are specific and limited experiences, that is, they have not been 'ramified '.
If it is about old wounds, traumatic experiences that go further back in time, it may take longer to solve because it may have affected other parts of the psyche.