He has the psychological aspect, but toned down.
Times, Sunday Times
The psychological aspect was being carefully looked at.
Mail and Guardian
For a start there's the psychological aspect: just try feeling tough in your socks.
Times, Sunday Times
The psychological aspect of chronic pain may be still stranger and stronger than we currently know.
Times, Sunday Times
However, there may be a psychological aspect to this, as you mention becoming obsessive.
The Sun