Is resilience the flip-side of vulnerability?

No. Vulnerability means to be at risk to develop mental dysfunctions. If resilience is the outcome of a process of successful adaptation to life stressors, measured „ex post facto“ (see What is resilience?), then resilience is in a different category than vulnerability. This does not exclude that certain genotypes, personality profiles or social factors are linked with a relatively decreased risk for dysfunctions. We refer to them as resilience-conducive individual characteristics. They are the flip-side of vulnerability. But our outcome-based definition of resilience prohibits to equate them with resilience.