This retrospective study identified a 28% reduction in psychiatric hospital admissions during the first year of the COVID-19 pandemic compared to the same period in the year before the pandemic. At the Department of Psychiatry, University Hospital of Split, Croatia, the total number of beds decreased by 20% during the pandemic’s first year, and outpatient hospital services were reorganized or temporarily closed. Despite the decline in psychiatric hospitalizations, the number of contacts with hospital psychiatric services – including emergency psychiatry department visits and urgent inpatient psychiatric consultations – remained relatively stable, with 4591 contacts before the pandemic and 4465 during the first year of the pandemic. This suggests that the demand for psychiatric care remained high, but psychiatric services have changed in response to the pandemic. It is possible that some patients who would have been hospitalized in the past were not admitted due to reduced capacity in beds and medical personnel, stricter admission criteria, or concerns about coronavirus infection. As a result, these patients may have been treated in other hospital departments via psychiatric consultations or may have not received the necessary medical care.

Our results are in line with the study about the impact of COVID-19 on psychiatric hospital admissions in Croatia between 2020 and 2022, which reported a significant average decrease in total admissions, and a 28% decrease in the number of admissions of psychiatric patients at both secondary and tertiary hospitals [4]. A study from the largest special Psychiatric Hospital Vrapče in Zagreb, Croatia, also found a significant decline in hospitalizations during the COVID-19 pandemic [22]. Similarly, studies from Germany [7, 8], Italy [9, 10], Portugal [11], South Korea [12], and Australia [13], also indicated a decrease in psychiatric hospitalizations due to the COVID-19 pandemic. There are several explanations for the observed reduction in psychiatric hospitalizations. A decrease in psychiatric hospital admissions was possibly due to the fear of acquiring infection in hospitals [9, 11, 22, 23]. There was widespread attention in the media on the high danger of contamination in hospitals [10], which has likely contributed to the perception of hospitals as unsafe places [24]. There might have been an increase in the stringency of the admission criteria [9, 11]. Finally, the reduction in available beds due to COVID-19-positive patients and staff shortages likely affected the hospitalization rates [11]. The reduction in available hospital beds made it harder for people with mental health problems to get the care they needed. This is an important lesson to consider when planning for future crises, where balancing infectious disease control with mental health needs will be critical [25]. Furthermore, online consultations have supplanted in-person consultations worldwide [26, 27].

Another important study finding is the shift in diagnostic categories of hospitalized patients, with a tendency to hospitalize individuals affected with more severe mental diseases during the COVID-19 pandemic. Notably, in the first year of the COVID-19 pandemic, hospital admissions due to schizophrenia, schizotypal, and delusional disorders (F20-29) increased to 61% from 52% in the year before. Multiple studies suggested lockdown measures have likely contributed to an increase in these admissions. Loneliness poses a direct risk to psychological health. Limited social interactions and possibly the break from the usual daily routines allowed vulnerable patients more time to dwell on negative thoughts, which could develop into paranoid thinking. Also, the uncertainty and fear of virus transmission from others may heighten pre-existing paranoid tendencies and deepen feelings of suspicion toward others. These factors likely exacerbated pre-existing mental health conditions, particularly in individuals with psychotic symptoms [15]. It was also proposed that COVID-19 infection could worsen existing symptoms in individuals with schizophrenia, as coronaviruses might be linked to psychotic symptoms via an immune-related process [1].

Studies from the UK [28], Italy [29], Australia [30], and Portugal [11] support this association, with a documented increase in admissions for diagnoses like nonaffective psychoses, schizophrenia, and acute transient psychosis. The COVID-19 pandemic caused significant stress, social isolation, loneliness, financial strain, and disruption of usual routines, which could have exacerbated symptoms or triggered the onset of psychotic symptoms. Also, lockdowns and restrictions disrupted access to regular mental health services, potentially leading to worsening symptoms and increased need for hospitalization [15]. There is growing evidence that COVID-19 infection might have direct neurological effects, potentially increasing the risk of developing mental health disorders [31,32,33]. Psychotic symptoms, such as delusions, hallucinations, and disordered conduct, can cause risky behavior, particularly violent or suicidal thoughts. These problems necessitate immediate attention, frequently involving family or legal action. However, patients with schizophrenia may find it difficult to maintain social withdrawal and protective measures, making them vulnerable to the restrictions created by the ongoing pandemic circumstances and more susceptible to decompensation [1]. A systematic review highlighted increased COVID-19 infection and mortality rates of individuals with schizophrenia spectrum disorders compared to the general population and paradoxically, access to intensive care units for this vulnerable group did not appear to be prioritized. Patients with schizophrenia spectrum disorders constitute a high-risk group requiring fair access to healthcare support during public health crises like COVID-19 and top priority in national COVID-19 immunization campaigns, as well as guaranteeing prompt access to the intensive care unit [34].

However, studies from Croatia [4], South Korea [12], and Turkey [35] reported a significant decrease in hospital admissions for psychotic disorders, including schizophrenia, schizotypal and delusional disorders during the COVID-19 pandemic. Limitations in community-based mental health infrastructure and support networks for managing individuals with psychosis might have contributed to these findings [12].

Our finding of a noticeable reduction in hospital admissions related to neurotic, stress-related, and somatoform disorders (F40-F48) during the COVID-19 pandemic is concordant with studies from the UK [15, 28], Croatia [4], Spain [36], Germany [7], and Portugal [11]. Several factors likely contributed to this finding, such as reluctance to seek professional help, potentially due to heightened anxieties and concerns about virus exposure in hospitals [37]. Furthermore, limitations on movement and potential changes in healthcare service availability could have further hampered access to mental health care during this time [11, 37].

In this study, patients hospitalized during the COVID-19 pandemic were more burdened with a positive personal history of psychiatric diseases. Similarly, a Turkish study showed higher emergency admission rates for patients with prior psychiatric history during the lockdown and pandemic [35]. In contrast, Beghi et al. reported a dramatic decrease in patients with previous psychiatric history between 2019 and the COVID-19 period [29]. The COVID-19 pandemic has interrupted mental health care, causing symptoms to worsen, and increasing the need for hospitalization among those with pre-existing psychiatric disorders [11, 38]. Supporting these findings, a multi-country study identified a link between pre-existing mental health conditions and worsening symptoms during the pandemic [39].

According to our data, there was a significant decrease in the proportion of patients with psychiatric comorbidities hospitalized in the COVID-19 period. We were unable to find studies that confirm our results. However, during the pandemic, significantly more patients were admitted due to schizophrenia and delusional disorders, who mostly have one diagnosis; and fewer patients were admitted with diagnoses such as affective disorder, anxiety disorders, and adult personality disorder, which mainly have more than one psychiatric diagnosis. On the other hand, it is also possible that this finding was a direct consequence of the reduced quality of patient assessment due to strain on the hospital system during the COVID-19 pandemic.

A worrying finding was a significant increase in admissions due to suicidality (almost 3-fold), and heteroaggresion or both autoagression and heteroagression (almost 4-fold) during the COVID-19 period. Other studies documented a concerning rise in suicidal ideation during the COVID-19 pandemic [9, 25, 40]. Beghi et al. found that admissions for suicidality and heteroaggression increased during COVID-19 [29]. Similarly, Abbas et al. reported that patients admitted for psychiatric care during COVID-19 more often exhibit potential for aggression [28]. The COVID-19 pandemic introduced a multitude of stressors known to exacerbate suicidality and aggression, including social isolation, economic strain, and domestic violence. Lockdowns and restrictions may have exacerbated existing mental health issues, leading to more urgent admissions [24, 41,42,43]. It was also found that individuals under lockdown or shelter-in-place orders experience an increase in suicide thoughts each month, while those without such restrictions remain stable. Addressing this issue in public health policy and routine clinical care is crucial [44]. Furthermore, a systematic review underscores the potential negative psychological effects of quarantine, including post-traumatic stress symptoms and anger. This emphasizes the need for targeted interventions to minimize the duration and psychological burden of quarantine measures, alongside clear communication and resource provision [45].

During the healthcare crises such as COVID-19 pandemic, it is crucial to focus on promoting mental wellness in the public to reduce stress, anxiety, fear, and loneliness. Traditional and social media programs should be implemented to encourage positive mental health and alleviate suffering, thus preventing the rise of suicidal ideations. Every individual plays a vital role in maintaining their mental well-being, and it is essential to prioritize self-care during these challenging times [41]. It is crucial to recognize the importance of safeguarding the mental health of vulnerable individuals as a top priority for public health. On-demand telepsychiatry has proven to be an effective solution that offers better continuity of care, while also reducing the burden on emergency departments, shortening discharge timelines, and decreasing psychiatric hospitalization rates. Additionally, it has been linked to positive outcomes and high patient satisfaction. The COVID-19 pandemic provided an opportunity to break down cultural, technological, and normative barriers that have prevented people from utilizing telepsychiatry services in the past [46].

Our results showed a lower number of admissions due to intoxication and new psychiatric disease during the COVID-19 period. The pandemic altered social behaviors, restricted access to substances, and affected mental health help-seeking. Reduced social gatherings and lockdowns likely contributed to fewer intoxication-related admissions. According to data from the European Monitoring Centre for Drugs and Drug Addiction, drug use has decreased overall during the first 3 months of the COVID-19 pandemic [47]. A study from France also found a decrease in first-episode psychiatric consultations during the COVID-19 pandemic [48], which can be partly attributed to a more stringent threshold for seeking initial mental healthcare.

The observed increase in hospitalizations for aggressive behavior during the pandemic was also reflected in the changes in the admission mode of patients. In the COVID-19 year, more patients arrived in police custody or with both the police and ambulance compared to the control year. A study from Germany also showed a significant increase in the proportion of patients brought in by police during the pandemic [25]. The rise in police involvement might reflect a higher level of crisis among patients during the pandemic. Stricter social distancing rules could have been especially challenging for individuals with schizophrenia or impulsive personality disorders, leading to more police interventions. Indeed, patients brought in by police custody often display severe symptoms like delusions, aggression, suicidal thoughts, or attempts [25].

More severe reasons for admissions and admission diagnoses observed during the pandemic could partially explain a significantly longer length of hospital stay; from 14 days before the pandemic to 15 days in the first COVID-19 year. Several studies also reported longer lengths of stay during the COVID-19 pandemic [9,10,11], possibly because admitted individuals had more severe conditions and required longer hospitalization [10], although opposing findings also exist [8, 25].

Our patients hospitalized during the COVID-19 year were significantly younger compared to the inpatients in the year before, although the difference was small. Australian study also showed that patients admitted during the COVID-19 period were younger [13]. Moreover, a Korean study found that outpatients visiting during the COVID-19 pandemic were younger than those in the pre-COVID-19 period [37]. Older adults experienced lower psychological distress associated with COVID-19 due to higher levels of resilience, despite experiences of social isolation, more severe symptoms, and limited access to healthcare [49]. There was a social stigma about the elderly as they were perceived as contagious. Older age is a known independent risk factor for the severity of COVID-19 and the associated mortality [50], leading older adults to attend the hospitals less frequently due to the fear of infection.

The observation of increased hospitalizations of patients with higher education during the COVID-19 pandemic was in line with the study from Melbourne on the effects of a lockdown on inpatient admissions [13]. Those with a higher education level may have been more affected by the changes as their customs and routines have been disrupted by the pandemic [51]. People with a higher level of education mostly have a more complex structure of daily activities. Their routines, which are often closely related to academic and professional duties (like research, lectures, meetings, administrative tasks), were significantly disrupted by the transition to working from home, cancellation of conferences and events, and difficulties in conducting research. These changes probably led to increased workload, isolation, and mental health problems among people with higher levels of education, in contrast to people with lower levels of education, whose jobs were often less affected by the pandemic. Also, the pandemic caused a delay in seeking help for mental health issues among the general population. However, individuals with higher education levels might have been more likely to seek professional help during a crisis, because participants with higher education perceived more negative effects than those with lower education [52].

During the COVID-19 pandemic, patients treated at our department have been discharged from the hospital in better health condition than before the pandemic. We were unable to find studies in the literature investigating the discharge status of psychiatric patients during the COVID-19 pandemic. Prolonged hospital stays may have contributed to this increase, as patients with higher clinical severity may have been admitted during the isolation period. Only patients more likely to benefit from hospitalization were admitted, resulting in a higher discharge rate with improvement. Furthermore, clinicians may have kept patients in the hospital longer to reduce the possibility of readmission, as there was a greater chance of infection outside the hospital [9]. Finally, the proportion of readmitted patients remained unchanged between the control period and the first year of the COVID-19 outbreak (15%), similar to findings from the UK [15] and Portugal [11].

Study limitations

Our study has several limitations. First, the retrospective design could not control unknown confounders that might influence the results. Second, study generalizability is limited due to a single-center setting. Discharge diagnoses and discharge assessments were made by different psychiatrists which could introduce bias. Also, the discharge status was subjectively assessed, therefore it was not uniform and objective. Furthermore, we were unable to acquire data about readmission to other hospitals and the number of non-urgent inpatient psychiatric consultations. Most importantly, we could not estimate to what extent the reduced capacity of psychiatric beds observed during the first year of the COVID-19 pandemic influenced the reduction in the number of hospitalizations.

Relevance of the study

Of the available literature at the time of writing, no studies assessed such detailed characteristics, modality, and causes of psychiatric admissions during a year after the emergence of COVID-19 in Croatia and possibly broader. Our research covers the entire first year of the COVID-19 pandemic, while most similar studies we identified in the literature only covered the lockdown period.

This study’s findings are highly relevant both regionally and internationally, despite its focus on a single institution and country. The study provides critical insights into the impact of COVID-19 on psychiatric admissions in a high-volume tertiary hospital setting, highlighting trends that may inform mental health policy in a region with few data available, it can help with future resource allocation, and emergency preparedness both regionally and in comparable settings worldwide.

Namely, Croatia is part of South-Eastern Europe, which has a distinct cultural, economic, and healthcare-specific factors that may impact mental health differently than in other regions. Thus, the study has regional relevance with broader implications. To our knowledge, similar studies from this part of the world have not been published.

Also, even though this study was conducted in a single hospital, this is a high-volume hospital serving more than a quarter of the Croatian population and a large part of Bosnia and Herzegovina. Specifically, about one million citizens of the Republic of Croatia and about half a million citizens of the southern part of Bosnia and Herzegovina, as well as half a million tourists during the tourist season, gravitate to this hospital [17].

Tertiary hospitals typically handle complex or severe cases, making this setting especially valuable for identifying trends in acute psychiatric admissions. Changes observed here may reflect the impact of the pandemic on the most vulnerable populations with severe mental health needs. As tertiary institutions often serve as hubs of specialized care, the findings provide a concentrated view of pandemic-related challenges that are likely representative of trends in other tertiary hospitals.

Furthermore, the study has international relevance because its findings reflect broader trends in the psychological impact of the COVID-19 pandemic observed globally. The significant increase in hospitalizations for suicidality, aggression, and severe disorders like schizophrenia aligns with similar concerns documented in other regions. This makes the study applicable beyond Croatia, providing valuable insights that can inform global mental health policies and crisis preparedness, as other health systems face similar challenges in providing continuity of psychiatric care under public health crises.

The study also provides insights into immediate healthcare system adaptation during public health crisis. Internationally, healthcare leaders can use these findings to shape strategies and allocate resources toward the most vulnerable populations, emphasizing the importance of flexibility in hospital capacity, telepsychiatry, and emergency mental health response. The study findings can be a foundation for policy and resource planning; it can help guide the scaling of mental health services, especially in emergency preparedness and in setting priorities for resource distribution.

Importantly, the study provided comparative data for future studies, both within Europe and globally. This type of detailed, regional data strengthens the international body of evidence, helping researchers to better understand and prepare for the psychiatric impacts of pandemics. The study can potentially encourage similar studies in other countries or regions. This could lead to a more comprehensive, global picture of how psychiatric services were impacted by the pandemic and help identify universal and region-specific challenges.