Associations between Mild Traumatic Brain Injuries, Event-related Po- Tentials, and Major Depression Disorder

Over the years, the relati onship between mild traumati c brain injuries (mTBIs) and depression has been thoroughly examined, and a strong positi ve correlati on between the two variables has been found (Chrisman & Richardson, 2014; Guskiewicz et al., 2007; Holsinger et al., 2002). However, not many researchers have investi gated what happens structurally and functi onally to the brain that allows this relati onship to exist. In the past, concussions and severe depression have both been linked to a smaller error-related negati vity (ERN) amplitude (Broglio et al., 2011; Duncan et al., 2011; Olvet, Klein, & Hajcak, 2010; Ponti fex et al., 2009). Here, we proposed that a smaller amplitude in ERN is the mediati ng factor between mTBIs and depression. The present study evaluated a populati on of high-impact sports athletes with a history of mTBIs for levels of depression and ERN amplitude. All the parti cipants, N=17, completed the Beck Depression Inventory-II (BDI-II) to assess for severity of depression, and a modifi ed fl ankers task to evaluate for ERN amplitude. Although not stati sti cally signifi cant, the results show a mediator model trend where the correlati on between concussions and depression decreased once the ERN was controlled for. Even though these fi ndings suggest that the ERN is not a mediati ng factor, if further studies with larger sample sizes and controls were conducted a stati sti cal signifi cance could appear.