MAPT and Anxiety: Another investigation, involving 109 military personnel and veterans, predominantly with mTBI (94.1%), revealed that serum tau was positively associated with total NSI and PHQ-9, as well as the PCL-Negative Mood subscales.119 Furthermore, a study focusing on veterans with repeated mTBI showed that plasma tau was significantly associated with the total PHQ-9, as well as correlating with total NSI.106 Within the TBICoE study, baseline serum tau (mean 7.5 months post-injury) was significantly associated with anxiety at follow-up (mean 36.2 months post-injury using the TBI-QOL anxiety scale).100