Mild traumatic brain injury (MTBI) is common and results in persisting disability for a minority of cases. Evidence guiding clinical management of this more complex group is lacking. This study systematically reviews psychological/neuropsychological treatments for adults with MTBI, with an emphasis on external validity. A total of 8 further studies were found adding to 10 from previous reviews. Although the methodological quality remains poor, mild supportive evidence was found for educational interventions provided early following injury. However, the routine provision of interventions for all MTBI cases may not be effective. Continuing and novel research efforts are needed to identify factors associated with poor outcomes to enable efficient targeting of healthcare resources.