A total of 18 studies were identified, including 13 primary research articles and 5 literature reviews (see Fig. 1).
The 5 literature reviews aimed to compare the effects of different interventions on PTSD, depression, and anxiety [21, 22•, 23, 24••], and identify the factors that influence the delivery and effectiveness of interventions [22•, 24••]. In terms of the nature of the event, one review  focused on different types of natural disasters, while the rest explored interventions delivered in a wider range of potentially traumatic experiences [22•, 23, 24••], including disasters, sexual and physical abuse, war, terrorism and other humanitarian crisis. Additionally, one review  focused on identifying interventions for children and families in the context of COVID-19 and comparable outbreaks. No further description of the reviews will be provided in these results because they assessed studies that were either conducted prior to 2018 or were captured in this scoping review. However, the literature reviews will be referred to throughout the discussion to indicate similarities and differences in the findings that have emerged from the more recent primary research studies.
The 13 primary research studies corresponded to 13 different interventions and will now be described in detail in the results below.
When and Where Were the Interventions Implemented?
The studies identified by this review were carried out in different countries across Asia [26, 27•, 28, 29•, 30, 31], the Americas (four, with two interventions from the USA [32, 33] and two from Canada [34, 35], Europe [36•], Africa  and Oceania ).
Table 1 summarizes the main characteristics of the interventions identified in this review. The interventions were carried out between 2006 and 2020, although four studies did not report when the post-disaster intervention occurred (and how long after the disaster) or its duration. Four interventions were implemented while the COVID-19 pandemic was happening [30, 32, 34, 35], two interventions were carried out within a few months of a disaster [29•, 37] and three interventions were implemented 1 year after the disaster or shortly after the first anniversary [26, 33, 38].
Interventions for child mental health were performed in response to pandemics—mostly COVID-19 [29•, 30, 32, 34, 35, 37], earthquakes [31, 36•, 38], floods [27•], hurricanes , tsunamis , typhoons  and volcanic eruptions . Ten out of thirteen interventions were carried out in school contexts [26, 27•, 28, 29•, 30, 31, 33,34,35, 36•]. Eight interventions were delivered face to face [26, 27•, 28, 31,32,33, 36•, 37], while the rest were online [29•, 30, 34, 35, 38]. Almost all the online interventions [29•, 30, 34, 35] were designed in response to the challenges of accessing children during the COVID-19 pandemic in 2019–2020, with one exception that was delivered after an earthquake . This was the only study to report problems caused by frequent technological glitches and high attrition rates.
Most interventions were delivered by clinically trained personnel and mental health professionals [27•, 31,32,33, 36•, 38], or by researchers with a background in mental health [28, 29•, 34, 35]. Four studies reported that interventions were delivered by or with the support of local teachers [26, 30, 33] or community workers , but did not provide details on whether these deliverers had also been affected by the disaster themselves.
What Type of Interventions Were Implemented?
The interventions identified in this review were based on a diverse set of frameworks, drawing mostly from therapeutic approaches like cognitive-behavioural therapy [27•, 32, 38], EMDR [36•], art therapy [35, 37], yoga therapy, play therapy, child development  and group therapy [28, 31], but also from mindfulness [30, 34], philosophy for children , health promotion and education [29•, 33], community-based interventions , coaching  and peer education [29•] (see Appendix 1).
Table 1 shows that the most common aim for interventions was to reduce symptoms of psychological distress (e.g. anxiety, mood, inattention and hyperactivity) and improve coping skills [27•, 31, 32, 34, 35, 36•, 37]. Other interventions aimed to promote resilience and emotional intelligence [27•, 28, 30], social support [27•, 29•], self-expression , self-efficacy  and self-esteem . Only one intervention explicitly aimed to engage children and youth in disaster recovery activities .
Six interventions corresponded to level 1 in the stepped care model [26, 28, 33,34,35, 37], four interventions were classified as level 2 [27•, 29•, 30, 31] and three interventions corresponded to level 3 [32, 36•, 38]. Most interventions (N = 10) were delivered in groups [26, 27•, 28, 29•, 31, 33,34,35, 36•, 37] and three were delivered to individual children [30, 32, 38]. The activities used to promote mental health varied greatly across interventions. They included sports [26, 29•], psychoeducation [27•, 32, 38], mindfulness, meditation or relaxation techniques [27•, 30, 34], cognitive and behavioural restructuring techniques [27•, 32, 38], art [35, 37], play [31, 37], group therapy techniques , philosophy discussions , volunteering in the community , engaging in disaster recovery , and EMDR group sessions [36•]. Most interventions had fixed contents, meaning they were designed to deliver standardised content in a standardised format [26, 27•, 28, 29•, 30, 34, 35, 37, 38], although researchers in one study reported that the frequency of sessions could not be kept the same across sites . In two other studies, researchers reported that the intervention was outlined in broad terms and then tailored to the needs of the community  or individual patient being targeted [36•].
How Did the Interventions Align with the Five Essential Elements of Disaster Recovery?
Figure 2 shows how the different interventions aligned with the five essential elements of disaster recovery (safety, calm, connectedness, efficacy, hope) . Only one intervention  explicitly stated an intent to address one of the five elements: self-efficacy. However, for the rest of the interventions, it was possible to link their objectives with different elements.
From this perspective, most interventions served to promote a sense of safety (N = 9), followed by calm (N = 8), connectedness (N = 5), efficacy (N = 4) and hope (N = 3). All the interventions that addressed connectedness [27•, 29•, 33, 37] and hope [33, 34, 37] were classified as either level 1 or 2 interventions. Some interventions also included additional components such as physical health aspects (sleep and exercise).
How Were the Interventions Delivered?
The duration of interventions ranged from a single session to 2 years, with the majority lasting about two months (Table 1). The scale of interventions varied from a sub-section of a school [34, 35], to school-wide [26, 33], to different locations within a city , region or nation  (Appendix 1).
Most interventions involved multiple sessions at regular intervals, that lasted between 45 and 60 min (Table 1). Most interventions had weekly sessions [27•, 33,34,35, 36•], and three had more than one session per week (between 2 and 4) [26, 29•, 37]. Exceptions included, a single-session intervention , a 10-session online self-paced intervention  and brief daily mindfulness exercises .
Who Received the Interventions?
All the interventions identified in this review worked directly with children to support their mental health and almost all of them (N = 10) were delivered to groups of children [26, 27•, 28, 29•, 31, 33,34,35, 36•, 37] (Appendix 2). Some targeted children between ages 7 and 13 [27•, 34, 35]; others worked with different ages and stages [31, 33, 37] but did not report how they tailored activities to the different ages, except one intervention  which reported two different modes of delivery: for ages 7–12 years and for 13–18 years. Three studies [28, 31, 36•] did not report the age of the children receiving the intervention. No interventions were specially developed for preschool children. Five interventions also offered support and information to parents/caregivers [27•, 32, 37, 38] or teachers .
What Intervention Evaluation Study Designs Were Used?
A range of study designs were used to assess the impact of the interventions (see Table 2). The randomised experimental trials and randomised cluster trials provide the greatest strength of evidence in terms of study design [27•, 29•, 34, 35] but sample sizes were small (ranging from 22 to 141 participants). Quasi-experimental trials were also common [26, 28, 30, 31, 33] (where participants are not randomly assigned to the intervention or the control group). Importantly, only one study  carried out a longitudinal analysis of the impacts of an intervention 2 years after the disaster.
Table 2 also shows that the sample size varied greatly across all the studies, from 1 to 332 children. Small sample size was a common limitation reported by studies [26, 34, 35]. Most studies reported the age and gender of children and aimed to achieve a balance between female and male participants. Only three studies reported on the involvement of children from minority groups [27•, 33, 38]. None of the studies reported involvement of children with disabilities. Only two studies [27•, 38] reported the socioeconomic status (SES) of their participants but did not use that data to examine the effect of SES or to adjust for SES in assessment of intervention impacts.
Table 2 also shows the interventions according to their expected outcomes and measures, demonstrating the wide range of standardised measures used to evaluate outcomes related to different aspects of children’s mental health, behaviour and wellbeing. Only one study  incorporated a measure of children’s level of disaster exposure before receiving the intervention.
What Were the Outcomes and Impact of the Interventions?
Considering the study limitations in strength of evidence as described in the previous section, the studies considered in this review suggested an overall positive impact of the different interventions in terms of reducing PTSD symptoms, depression, anxiety, sleep problems and promoting resilience, perceived social support and self-efficacy [26, 27•, 28, 29•, 31,32,33,34,35, 36•, 37].
However, findings were often mixed in terms of which aspects of the interventions were most effective and which sub-groups benefitted the most. One study reported that the intervention using group play therapy helped decrease PTSD symptoms including intrusions, avoidance, negative alterations in cognitions and mood, and alterations in arousal and reactivity , and another study [36•] found that EMDR group interventions were more effective in females and older children. While most level 2 and 3 studies included a measure of PTSD symptoms, almost all the PTSD and other outcomes were determined using self-report measures. Only two level 3 studies [32, 38] determined anxiety symptoms through diagnosis from a specialized clinician.
In relation to interventions that also had a component to support teachers  or parents/caregivers [27•, 32, 38], only one study  assessed the impact of the intervention on adults’ mental health. However, this evaluation measured the impact of the intervention on teachers and students together, so it is not possible to make any conclusions about the intervention’s effects on adults.
In addition to limitations already noted in relation to sample size and lack of diversity, study authors reported participant attrition , lack of follow up over time [34, 35], variations in the implementation of interventions across different study sites , and not assessing other potential sources of support that may have influenced the outcomes of an intervention . Several studies reported not using randomised control groups [33,34,35, 36•, 37, 38] because of ethical concerns. Limitations of instruments used for measuring intervention effects included uncertainty about reliability of translated questionnaires [26, 28], challenges assessing complex concepts with multiple dimensions like resilience  and bias in clinical assessments . Details on cost-effectiveness, inclusiveness, risk management strategies (e.g. mitigating risk of re-traumatisation) and implementation processes were also commonly missing from evaluation reports (see Appendix 3).