The pair formed a strong defensive bond as the club sealed Champions League qualification on the final day of last season
Arsene Wenger has struggled with defensive pairings of late, with Thomas Vermaelen struggling for form and Sebastien Squillaci released at the end of last season after making just 23 Premier League appearances in three seasons at the Emirates Stadium.
However, both Koscielny and Mertsesacker came to the fore, conceding just four goals in the 10 games they started together as the season drew to a close, and Adams has backed the pair to thrive again next term.
"It's the only position where you need familiarity," Adams told the club's official website. "You need to play with your mate on a regular basis to gain confidence and I think that really worked for Arsenal defensively.
"[Wenger] left that alone and they gained confidence. It's the fact that they play regularly with each other that they've learnt [about] each other's game.
"I used to play with Steve Bould. We used to play zonal defence. Steve was a zonal defender and he knew how that system worked. Playing with Martin Keown was different. He was a man-to-man marker and when I used to play with Martin, I used to play differently alongside him.
"To keep changing that scenario is very difficult. If I was playing with Bouldy one week and then Martin the next, it would have been very difficult for me to go from one to the other.
"I think that's what really helped Koscielny and Mertesacker - that they got to know each other's game. For me, Mertesacker is a zonal defender and Koscielny is a man-to-man marker. They got to know each other's game because they played with each other week in, week out."
Koscielny's impressive displays in north London have attracted interest from Barcelona and Bayern Munich, with the centre-back expected to fetch up to €20 million if sold.