Displacement due to armed conflict in developing countries is increasing (1, 2). Displacement is a traumatic event that disrupts families and affects physical and psychological health at all ages (3–5). At least two-thirds of the countries in Africa have experienced conflicts leading to the displacement of millions of people (6).

Epidemiological evidence shows that the burden of mental disorders is becoming higher, particularly in post-conflict and conflict-affected populations (7, 8).

Mental disorders are a significant public health problem and 14% of the total burden of disease has been attributed to neuropsychiatric disorders including depression and other common mental disorders (9). Additionally, the proportion of global Disability Adjusted Life Years (DALYs) attributed to mental disorders increased to 4.9% (3.9–6.1) and Years lived with disability (YLDs) contributed to most of the mental disorder burden, with 125.3 million YLDs (95% UI 93.0–163.2; 14.6% [12.2–16.8] of global YLDs) in 2019 (10). Exposure to repeated trauma and extreme violence such as torture is associated with an increased risk for a mental disorder, including post-traumatic stress disorder, depression, anxiety, schizophrenia, and bipolar disorder (7, 11–13).

Recent meta-analyses of several studies published between1980 and 2017, where estimated the prevalence of PTSD (96/129; 74.4% of the studies), depression (70/129; 54.3% of the studies), and anxiety (38/129; 29.4% of the studies) identified a relationship between exposure to different types of disaster and conflict-related events and mental health disorders including anxiety, depression, and PTSD (7). The prevalence of mental health diseases was 21% (95% CI 18.8–25.7) at the point in time in the conflict-affected populations assessed (7).

According to the results of another meta-analysis, an estimated 242 million adult war survivors living in post-conflict areas were affected by PTSD, while major depressive disorder affected an estimated 238 million and 117 million suffering from both conditions (14). According to the findings of this meta-analysis, the estimated adult war survivors with PTSD, major depression, and both conditions in Mozambique were 2,339,450 (95% CI, 1,919,902–2,785,528), 2,296,218 (95% CI, 1,933,657–2,679,412) and 1,124,917 (95% CI, 695,524–1,557,525), respectively. (14).

According to studies of the general population, PTSD prevalence ranges between 1 and 5% (15, 16), while it has been shown to range from 3 to 58% in high-risk groups, such as those in conflict areas (16). Another systematic review reported that 3 to 88% of people in the general population have PTSD (7, 17). This is the case in Nepal and Palestine where PTSD prevalence is 53.4% (18) and 68.9% (19) respectively. Additionally, cross-sectional studies conducted among Internally Displaced People (IDP) assessment at community revealed that the prevalence of PTSD was 63% in Nigeria (20), 19.3% in Morocco (21), 28% in South Sudan (22), and 58.4% in the north (23) of Ethiopia.

On the other hand, mental health affects the immune system, damaging the body’s immunity and defenses and leaving the individual more susceptible to infections; the endocrine system, increasing or decreasing the production of certain hormones; the nervous system, interfering with the production of neurotoxins (related to diseases such as Parkinson’s and Alzheimer’s disease), among other problems (24).

Mozambique hosts nearly 32,000 refugees and asylum-seekers, while more than one million people remain displaced internally due to violence perpetrated by non-state armed groups and the devastating impact of the climate crisis (Tropical Cyclone Gombe in March 2022) – where Mozambique is one of the most adversely affected countries in the world (25).

In October 2017, violence erupted in Cabo Delgado, northern Mozambique, when armed men occupied the Mocimboa da Praia district. This violence perpetrated by non-state armed groups worsened in 2020 resulting in an unprecedented humanitarian crisis with close to 1 million people living in a situation of protracted displacement (26). Violence against civilians continued such as killing, beating, extortion, widespread damage to property and core public services, severe violations of children’s rights, and conflict-related sexual violence (27). Due to this violence, 2000 civilians died and around 34% of people and 28% of families including 353,601 children, were displaced/forced to move to different locations within Cabo Delgado province and other regions of Mozambique such as Sofala and Zambezia in the center and Nampula and Niassa in the north (28). The main destinations of IDP arrivals in Cabo Delgado were Pemba, Metuge, Mueda, Ancuabe, and Montepuez districts (29, 30), where displaced people were initially housed in transitional accommodation centers and later resettled or returned to their places of origin. The IDPs still live in small, overcrowded temporary shelters in the camps, without sufficient food, clean water, or toilets. Their lives are on hold, and their futures are uncertain (26–29). Individuals with an experience of abuse/violence were at risk of increasing mental health problems.

Screening is effective only when combined with high-quality services for mental well-being.

One of the challenges to ensuring appropriate services for IDP in Cabo Delgado is the lack of statistical data on the group’s mental health status.

Despite the high prevalence of PTSD, depression, and anxiety in conflict areas around the world, data on the prevalence of PTSD, depression, and anxiety among IDPs in Mozambique, where we lived in a scenario of armed conflict (during 16 years of civil war), current terrorist attacks and violence since 2017, and recurring natural disasters are scarce. It is imperative to conduct research in this field to provide scientific support for the formulation of prevention and treatment plans for mental health issues during current and future civilian attacks or natural disasters. This study aims to assess the prevalence of symptoms and associated factors of post-traumatic stress disorder, depression, and anxiety among those who have experienced traumatic events during the armed conflict in Cabo Delgado province.

Nearly 120, 000 IDPs have lived in the resettle camps of the Metuge district since October 2017. During the displacement and post-displacement periods, IDPs faced multiple stressors (48). They live in small, overcrowded temporary shelters in the camps, without sufficient food, clean water, or toilets. Their lives are on hold, and their futures are uncertain. Individuals with an experience of abuse/violence were at risk of increasing mental health problems (17). This study provides a detailed view of the symptoms of traumatic distress (PTSD, depression, and anxiety) encountered by 25 de Junho resettle camps in Metuge district, Cabo Delgado province.

This study found a high prevalence of PTSD, depression, and anxiety symptoms in IDPs in Cabo Delgado province. People affected were relatively young, with 71.8% under the age of 44, and predominantly female (65%). The rate of illiteracy was 41% with 80% of respondents unemployed and 96.4% departed from Quissanga district-which is among the most affected by the armed violence affecting the province since October 2017 (30).

Our study participants had lower educational levels (90%) and a 41% illiteracy rate and women are almost twice as likely to be illiterate as men in concordance with the national average (39.9%) (32). The Cabo Delgado province, despite being abundantly rich in mineral and environmental resources, has the highest rate of illiteracy (52.4%; 12.5% above the national average in population aged 15 and above) and multidimensional poverty in the country (32).

Additionally, the study participants had a high unemployment rate (78%) which is in concordance with the last report of the National Statistical Institute in Mozambique (32). The aggregate prevalence of depression, anxiety, and post-traumatic stress was considerably high, with a prevalence rate of 63.8, 40.0 and 74.3%, respectively, when compared with other studies conducted in armed conflict-affected populations (10.8% for depression, 15.3% for PTSD and 21.7% for anxiety) according to a systematic review and meta-analysis (15). Another systematic review (1981–2014) from six countries, five in Africa (18 studies), reported that the most frequent being post-traumatic stress disorder (range 3.1–75.9%), anxiety (range 6.9–75%), and depression (range 8.8–76.5%) (49).

The prevalence of PTSD at 74.3% was in line with the study carried out in Uganda (74%) (50) and lower than a study done in Medellin Colombia (88%) (51) and Iraq (83.4%) (52). Contrarily, the estimated PTSD prevalence of the current study was higher than the studies carried out as 63% in Nigeria (21), 40.8% in northwest and 58.4% in south of Ethiopia (24, 46), 19.3% in Morocco (22), 28% in South Sudan (23), 29.9% in Somalia (53) and 7.7% in Sri-Lanka (54), 46.6% in Bangladesh (55) particularly among women (5, 24, 55, 56).

The possible explanation for the observed difference could be the difference in tools, in which northwest Ethiopia (46), and northeast Ethiopia (56) studies used the post-traumatic stress disorder checklist for DSM (PCL-5), in Sri Lanka and Sweden studies used the Harvard trauma questionnaire (HTQ) (54, 57), and in Somalia and Uganda studies were used the International Neuropsychiatric Interview (MINI) (53, 58).

The high prevalence of PTSSs suggests that a scale-up of mental health care is needed, which could be met by increasing medical workers’ capacity in the Metuge health facilities to diagnose and treat patients with mental disorders. However, the current resources for mental health services are insufficient in the Metuge district, and the number of mental health professionals (2) is too low to cover the entire Metuge population in need.

The prevalence of depression symptoms (63.8%) was higher than the studies carried out in Uganda (58%) (58), in the south (53.3%) (24) and North Ethiopia (39.3%) (46), Sweden (40.2%) (57), Sri-Lanka (22.2%) (54) and Somalia (32.1%) (53). Contrarily, the estimated depression symptoms prevalence of the current study was lower than the study carried out at 89% in Bangladesh (59).

Additionally, the prevalence of anxiety symptoms (40.0%) in the current study was lower than the study done in southwestern Uganda (73%) (58). On the other hand, the findings of the current study were higher than the study done in northeast Ethiopia (33.4%) (56), Sweden (31.8%) (57), Somalia (34.9%) (53), and Sri Lanka (32.6%) (54). A possible theory to explain the high prevalence of PTSD, depression, and anxiety symptoms may be the repeated exposure to war attacks and/or violence (previous and current armed conflict, natural disasters, and COVID-19 pandemic) (60) that these displaced individuals had been exposed to several moments (the last attack in Quissanga district being recorded 6 months before the beginning of the study) (61). Of note, the region has recorded extreme weather events, such as Cyclone Kenneth in April 2019, affecting around 500,000 households that saw their homes partially or destroyed, followed by the torrential rains recorded in December 2019 and January 2020 (62). Furthermore, the COVID-19 pandemic and several outbreaks of cholera caused limited access to essential health services and thousands of additional deaths (63).

PTSD was significantly associated with being female (2.2. times), suicide risk (1.54 times), being screened positive for depression (8.27 times), and generalized anxiety (1.45 times).

Approximately half the respondents in our sample were female. The study findings show that mental health symptoms were more prevalent in female IDPs than in male IDPs. The odds of developing PTSD were 2.3 times higher in females compared to males, in line with the findings of other studies done in the south (24, 64) and north of Ethiopia (46, 56), and the fact that females have a higher risk of developing PTSD due to a lower threshold from exposure to psycho-trauma compared to males (51). In addition, many studies show that women were found to have a higher incidence of mental health disorders after rape or sexual assault (12, 65), the violent loss of a partner, or children, and becoming a single parent or widow (50, 66). Another reason could be that females tend to show a more emotional and ruminative response to stress (67). Contrarily, some studies found that symptoms of traumatic distress were more prevalent among male refugees than female refugees. (12, 55, 65)

Our research also found that IDPs who were unable to read or write had a higher prevalence of mental health symptoms (PTSD, depression, and anxiety) than those who had schooling. This finding is comparable to previous research that showed that poor education level was correlated to higher rates of PTSD (55, 68, 69) and increased risk of developing PTSD, depression, and anxiety (70).

Also, married respondents were more likely to have PTSSs, depression, and anxiety than those who were never married. This finding is comparable to findings in previous research (69).

Participants with depression were 8 times more likely to have PTSD when compared to participants without depression. Among patients with PTSD, depressive disorders, anxiety disorders, and drug misuse are 2 to 4 times more prevalent than among patients without PTSD (71). This is consistent with research conducted in Ethiopia (24, 56), Uganda (58), and Kenya (72). This has been related to participants with depression being more likely to have suffered traumatic experiences compared to participants without depression (67). Moreover, PTSD may increase the risk of suicide attempts (73).

The high prevalence of self-reported mental health symptoms in this study was found in a displaced working-age population. Being female, having a clinical feature of depression and anxiety, and having antecedents of the death of a family member, were associated with the development of PTSD. These results highlight the need for surveillance and follow-up studies, and training on stress management for their violent memories in the context of humanitarian emergencies in displaced populations, aiming to early diagnose and deliver group or individual psychological support, may reduce the burden of severe mental health symptoms. Likewise, these results highlight the need for more evidence-based research specifically from policymakers and stakeholders at the national and global level to tackle the common mental disorders issues through intervention.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving humans were approved by National Bioethics Committee for Health of Mozambique with registration IRB00002657. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.

NM: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Visualization, Writing – original draft, Writing – review & editing. HI-M: Investigation, Writing – review & editing. FP: Formal analysis, Software, Writing – review & editing. PD: Validation, Writing – review & editing. FM: Conceptualization, Methodology, Writing – review & editing. VC: Validation, Writing – review & editing. AM: Supervision, Validation, Writing – review & editing. MM: Formal analysis, Funding acquisition, Software, Supervision, Validation, Writing – review & editing.