Final answer:
Post-traumatic growth is the term that defines the positive psychological change experienced as a result of the struggle with challenging life circumstances.
Step-by-step explanation:
Many individuals who face highly challenging life circumstances, such as a debilitating accident or the death of a loved one, can emerge having experienced improvements in their psychological functioning. The term that identifies this phenomenon is post-traumatic growth. This concept reflects a form of positive change that occurs as a result of the struggle with highly challenging life circumstances, leading to a range of positive outcomes that include newfound personal strength, deeper interpersonal relationships, and a greater appreciation for life.