**1. Introduction**

About 200 million people are annually exposed to disasters worldwide, according to the Centre for Research on the Epidemiology of Disasters [1]. Definitions of disasters have varied in the literature. Some authors have defined disaster as a serious disruption in the functioning of society due to an event or natural disaster such as an earthquake, flood, tsunami, etc., leading to environmental, human, economic, and biological damage [2]. On the other hand, Davidson & Baum defined disaster as the subjective psychological response to any event [3]. Regardless of the definition, many studies indicated that disasters have both objective destructive effects and psychosocial effects and consequences [4].

Today, there is extensive information based on studies on psychological and behavioral issues caused by natural disasters. A systematic review showed that the burden of PTSD among persons exposed to disasters is substantial [5]. Other adverse psychological outcomes such as depression, anxiety, stress, and suicide were also mentioned in some studies as disasters' outcomes [6]. For instance, the prevalence

rates of depression among youth post-disaster reported in a review ranged from 2 to 69%. This rate depended on potential risk factors identified, including female gender, exposure stressors, and post-traumatic stress symptoms [7]. Although mental disorders usually decrease in the second year after the disaster, in some cases, complications remain chronic [8]. Another critical issue is the vulnerability of the people themselves and the possibility of previous disorders in these people, which will undoubtedly lead to more severe reactions [9]. The simultaneous presence of several mental illnesses increases the intensity of mental damage. The most common disorder we deal with is post-traumatic stress disorder (PTSD), although in many cases, we find this disorder together with other disorders [10]. The most common co-occurring disorders are major depression, panic, and phobia. In fact, after a disaster, mental disorders attack a person, such as multiple injuries [11].

In addition to the negative psychological outcomes of disasters, there are some positive consequences, such as post-traumatic growth (PTG). For some people, exposure to disasters or any traumatic events, which may contain great suffering and loss, can lead to very positive changes in the individual [12]. About 30–90% of people with traumatic experiences at some point in their life have reported at least one form of PTG [13]. Different traumatic events have different effects on PTG, with people with severe trauma reporting greater benefits, and chronic events can have very different psychological effects than acute events [14]. In general, PTG refers to positive psychological changes and greater growth than the pre-crisis level of performance, which through cognitive reconstruction makes the person adapt to the new reality [14].

Another object that is related to psychological outcomes after disasters is resilience. There are many resources of stress in life; also, there is so much variability in how people respond to and manage life's stressors. Resilience refers to the process of a person's return to normal functioning after a stressful event or uncomfortable experience, but PTG refers to growth compared to the pre-disaster situation. We will explain this in a separate section [15].

Furthermore, the research results related to mental reactions after disasters give us a view of the common disorder and the needs of the survivors. We tried to explain psychosocial support in disasters according to our experiences after defining resilience.
