The Yorkshire giants have recorded 10 points from their opening four games at the second tier since the arrival of new head coach Marcelo Bielsa.
Douglas was a surprise signing from Wolverhampton Wanderers in the summer, but the left-back has revealed that he has quickly settled into life at Elland Road.
The 28-year-old is quoted by the club's official website as saying: "The team that has been involved has been pretty much the same as last season, apart from myself.
"I think a lot of credit needs to go to the lads for helping me integrate into the squad and the team and get going. The Championship is relentless, there is no time to dwell, so it is important that all of the new guys feel a part of it and hit the ground running.
"We have a really good squad, there is a lot of quality and I think the best is still to come, it is still early doors."
Leeds are next in action when they travel to Carrow Road to face Norwich City on Saturday.