Systematic Review of Preinjury Mental Health Problems as a Vulnerability Factor for Worse Outcome After Sport-Related Concussion

BACKGROUND: It is difficult to predict who will experience prolonged health problems after sustaining a sport-related concussion. PURPOSE: To synthesize the literature and conduct a gap analysis on the association between preinjury mental health problems and clinical outcome from sport-related concussion. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Data sources were PubMed, PsycINFO, MEDLINE (and MEDLINE in Process), CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science. Studies published before February 2019 that addressed preinjury mental health problems as a possible predictor of worse clinical outcome or clinical recovery from concussion were eligible for inclusion. RESULTS: Of 4013 studies screened, 358 full texts were reviewed, and 12 studies involving 3761 participants (n = 471 [12.5%] with preexisting mental health problems) were ultimately included. The participants with a preinjury history of mental health problems were at greater risk for having persistent symptoms or worse outcome in 9 of 12 studies. The studies had major methodological differences, and most studies were not focused on mental health as a primary predictor or prognostic factor. Rather, they included it as a secondary or tertiary predictor. The sample sizes with preinjury mental health problems in most studies were small or very small (ie, <25). The age of onset, type, course, severity, and duration of mental health problems were not defined. The extent to which mental health problems were present before the season, during baseline testing, was not reported. CONCLUSION: Preinjury mental health problems appear to confer risk for worse clinical outcome after sport-related concussion. Future research is needed to (1) examine this risk factor in large representative populations of middle school students, high school students, and collegiate athletes; (2) quantify the risk for each mental health condition; (3) understand the mechanisms underlying this increased risk; and (4) develop more refined treatment and rehabilitation approaches for these student-athletes.