He said while the AFL continues to actively explore the health of past players in relation to possible consequences of concussion the evidence available at the moment around the issue was not conclusive enough to make the link.
Former Western Bulldogs player Matthew Robbins raised the potential of a link between concussion and depression in the Herald Sun on Tuesday. He said he suffered depression towards the end of his playing career and suggested it may have been a result of heavy knocks he incurred while playing.
"The answer is we don't know, " Seward told AFL.com.au on Tuesday night. "We don't know yet but hopefully in time we will understand more about it. We need to get more information."
The AFL has taken a proactive approach to deal with the issue, making rule changes to protect a player's head and funding research into the issue through the AFL Research Board.
It also established a concussion working group in 2010 to assist the AFL research board in determining research priorities and ensuring the AFL remains at the forefront of developments in the area.
It continues to work with the AFLPA to develop strategies and direct funding to address the issue.?
Seward said it is becoming apparent that the American experience - where concussion in sport, particularly the NFL, has become a controversial issue - may be quite different to the experience of those playing AFL.
He said NFL players may be experiencing 1500 head knocks a year compared to AFL players who might have five or six concussive episodes over their career.
"To package the two of them together and confuse them may be creating of level of anxiety around players and past players about early onset dementia that is inappropriate," Seward said.
AFL research has already established that about six or seven AFL players a team are concussed annually.
Concussion guidelines released last year made it compulsory for a player to be subbed off the ground if they were diagnosed with concussion during a game.
