Comment by mcv
It's the exact opposite in Cypher. I'm currently working with some complex data in neo4j, and wondered why my perfectly fine looking queries were so slow, until I remembered to use DISTINCT. It's very easy to get duplicate nodes in your results, especially when you use variable length relationships, and DISTINCT is the only fix I'm aware of that fixes that.
Yeah, similarly combining distinct with recursive CTE's in SQL can be the difference between a n×n blowout or a performant graph walk that only visits nodes once.