How can defense mechanisms be considered both adaptive and maladaptive?

Defense mechanisms protect a person from emotionally painful stressors. However, since defense mechanisms can limit an individual from facing the situations that are harmful and unhealthy, one may be unable to successfully resolve troublesome or stressful issues as a result.

The defense mechanism is invented to adopt to resolve the conflict between two in a healthy manner.

Explanation:

Defense mechanisms can be considered both adaptive and maladaptive as follows:

The rigidity and the flexibility of the defense.weather it serves the adaptive equilibrium on the intended goal.The degree of which reality is distorted.when change is possible, denial may be maladaptive.when change is not possible, denial may be adaptive.The universal phenomenon is the part of adaptive function.

Where are the options ?