Multiple alternative definitions of resilience were elaborated, numerous of them referring to adaptation in the context of an adverse event, followed by a positive outcome, the lack of these specification making this construct difficult to be understood [1-3].

Resilience was suggested as but one of a number of constructs that protect or reduce vulnerability. Luthar [1] emphasized that resilience was a product of complex interactions of personal attributes and environmental circumstances, mediated by internal mechanisms.

The beginnings of the resilience's studies were represented by the researches of Werner and Smith, Rutter and Garmezy. The 30 year span of ethnographic Werner and Smith's study of high-risk children on the Hawaiin Island of Kauai, Rutter's research of children derived from unfavourable environments (Wight Island, underprivileged London's neighbourhood, institutionalized children from Romania), Garmezy's project “Competence” tried to establish which characteristics of the child made him/her overcome the adversities, which were the risk and protective factors that interact and produce a positive outcome, what could we learn from these and what could we apply in practice [4,5].

Is the concept of resilience useful? Does it possess a practical application?

Resilience perception and conceptualization have been changed through time.

From the study of resilience in the context of major traumatized events (abandon, parents decease, sexual abuse, natural disasters, accidents), researchers shifted to its examination during the chronic stress factors (poverty, intrafamilial conflicts, parents illness), and even during the wide context of life events and daily worries [4]. Masten [6] described resilience as a common phenomenon resulting from the operation of "basic human adaptational systems". According to Masten [6], resilience was made of ordinary rather than extraordinary processes which offered a positive outlook on human development and adaptation. The author asserted that all individuals possessed the mechanisms required for positive outcomes.

From the child resilience analysis, the adult resilience was conducted [7]. Adult resilience development could be associated with the interest in post-traumatic stress disorder [4].

The definition of resilience referring to a person was extended to a group, to different types of groups, to a community, to an ecosystem [8].

While the majority of the researchers described resilience as being an interactive and dynamic process, Block saw this concept as a personality-trait [9]. Block’s conception of ego-resiliency in adults was distinct from the developmental conceptions of resilience that focused on bouncing back in the face of adversity. Block depicted ego-resiliency as a meta-level personality trait, seen as flexibility in the control of emotion [10].

Several authors have made distinctions between the terms resilience and resiliency. Resilience reflects interactive processes between the child and his environment, while resiliency represents the attributes of the child [1,2]. Luthar [1] recommended always using the term resilience as opposed to resiliency when referring to the process of competence despite hardship.

The persons were considered to be resilient if they didn't have a psychiatric diagnosis [11]. Nowadays, we speak about resilience in schizophrenia, autism, intellectual deficiency, addictions [12,13] and disruptive behaviors.

Luthar [1] stated that it was possible for an individual to exhibit considerable resilience in one or more domains but not in others. Another Luthar's idea was that absence of pathology doesn't mean that an individual's resilience was high. It is also possible that a child may show resilience at one point in life and not at another [14].

The study of resilience went through several stages: identification of protective factors (personal, familial, regarding the community), identification and understanding of the resilience processes (compensatory, protective, moderating), identification of the interventions that enhance resilience (positive parenting, class interventions - Class Maps systems), genes and neurobehavioral resilience processes [10].

The factors that contribute to resilience may vary depending upon the nature of the adversity.

The results of the studies, conducted in order to identify internal resilience assets, found the following concepts important for resilience: social competence (social communication skills, empathy and caring, the ability to elicit positive responses from others), problem solving (planning, flexibility, and resourcefulness), autonomy (self-efficacy, self-awareness, and mindfulness), sense of purpose (goal direction, achievement motivation, optimism, and hope) [1,15,16], intelligence, attachment [3], coping skills, temperament, health, gender [17], locus of control [2,18,19], self-concept [20], a sens of optimism [21].

Family protective factors of resilience include: intimate-partner relationships, family cohesion, supportive parent-child interactions, a stable and adequate income [17], authoritative parenting style [20], maternal expression of positive emotion [22], organized home environment [21].

Community protective factors include: high expectations, meaningful participation [15], bond to pro-social adults outside family, high levels of public safety, support derived from cultural and religious traditions, civic engagement [21], early prevention and intervention programs, relevant support services, recreational facilities and programs, accessibility to adequate health services, economic opportunities for families, [3,17,20].

There are multiple models that attempt to predict the ways in which diverse factors might lead to positive outcomes for children. Compensatory models identify factors that neutralize the negative consequences of exposure to risk. Challenge models describe stressors as potential enhancers of successful adaptation. Protective factor models test how protective factors moderate the effect of a risk on the predicted outcome and modify the child’s response to the risk factors [20,23].

From self-recovery, due to a high resilience capacity, researchers orientated to the resilience building. Ionesco proposed the use of the term “assisted resilience” to the process of resilience enhancement, realized by the mental health professionals [4].

At the beginning, interventions were focused on the correction of existed deficits, in accordance with a “deficit model”. Afterward the process of recovery was concentrated on the identification of personal resources and modeling of resilience elements [24].

The complexity of resilience made difficult its standardized use and application. Several researchers and theorists have attempted to integrate the various research findings and their implications for practical application.

Kaplan [8,25] challenged the utility and integrity of resilience construct. He stated that resilience was a useful construct whose time has passed. Luthar [1], Elias, Parker, Rosenblatt [26] sustained that resilience was a useful construct, since it added value to the existing concepts.

The complexity of this concept made resilience hard to assess. The construct operationalization difficulty made researchers to develop many different scales, with reliability and validity hard to establish, making it difficult to compare results across studies and across groups.

The lack of consensus on definition of the construct [8], the existence of multiple, various elements of resilience, the numerous measures meant to quantify resilience cause confusion within the field and ignite criticism of resilience theory. These issues might be regarded as barriers to be overcome.

There is a need in the scientific realm for construct clarification for practical application and evaluation.