**3. Discussion**

#### **3.1 The complexity of frailty syndrome**

Life expectancy has rapidly increased worldwide, from 461 million people older than 65 years in 2004 to an estimated of 2 million people by 2050 [5].

This has a severe impact on social care.

In addition, frailty is the most problematic expression of population aging because it is strictly interrelated to the physical system such as the endocrine, muscle, cognitive and respiratory.

*The Complexity of Frailty: Psychological Mechanism and Therapeutic Interventions in Old… DOI: http://dx.doi.org/10.5772/intechopen.92630*

**Table 2.** *Flow chart of the literature selection.*

**Figure 1.** *Examples of casual and hardcore video games.*


*The Complexity of Frailty: Psychological Mechanism and Therapeutic Interventions in Old… DOI: http://dx.doi.org/10.5772/intechopen.92630*

