The COVID-19 pandemic and its associated public health measures have been extensively studied for their impact on mental health. Early studies revealed varied results regarding psychiatric admissions, with some showing decreases and others increases, depending on the specific policies implemented in different regions. While lockdowns were often linked to reduced admissions, this effect wasn't universal. Increases in anxiety, depression, and suicidal ideation were reported in some areas, contrasting with findings of decreased non-suicidal self-injury (NSSI) in others. This variation points to the complex relationship between pandemic response strategies and mental health outcomes. This study focuses on the often-overlooked long-term consequences of the pandemic on inpatient psychiatric care, specifically aiming to evaluate the impact of the pandemic on psychiatric hospital admissions to Mount Carmel Hospital in Malta and correlate observed changes with Malta's pandemic timeline. This investigation uses data from the first two years of the pandemic (2020 and 2021) compared to pre-pandemic data from 2019. Google Community Mobility Reports, which track population movement, will also be used as a proxy for the level of restrictions and public sentiment throughout the pandemic. This detailed examination aims to provide insights into the long-term effects of restrictive measures on mental health, helping inform the response strategies for future health crises.

Existing literature on the mental health impact of the COVID-19 pandemic reveals a complex and inconsistent picture. Early studies often focused on the immediate effects of lockdowns, reporting both decreases and increases in psychiatric admissions depending on location and specific policies. Some research demonstrated increases in anxiety, depression, and suicidal ideation, while others showed decreases in non-suicidal self-injury, especially among women. These inconsistent findings highlight the challenges of evaluating the impact of diverse pandemic response strategies on mental health outcomes. There is a significant gap in understanding the long-term effects of the pandemic on inpatient psychiatric services, with limited data available on this crucial aspect. This study attempts to address this research gap by focusing on a detailed longitudinal analysis of psychiatric admissions in Malta, a region that employed restrictive measures without full-scale lockdowns, providing a unique perspective on the issue.

This retrospective longitudinal analysis reviewed all psychiatric inpatient admissions to Mount Carmel Hospital in Malta from 2019 to 2021. The Shapiro-Wilkes test assessed data normality, and Student's paired t-test compared mean monthly admissions between 2019 (pre-pandemic), 2020, and 2021. To avoid Type II error, this approach was chosen over comparing proportions due to increases across multiple diagnostic categories. Ethical approval was obtained from the Institutional Review Board of Mount Carmel Hospital. Inclusion criteria included new and readmitted patients with documented psychiatric illness. A total of 4292 admissions were included after excluding patients returning from leave, those transferred to general hospitals, those with insufficient records, and those with unclear diagnoses. Data collected included demographics (gender, age, nationality), Mental Health Act (MHA) status (voluntary or involuntary), ICD-10 diagnostic categories, and the presence of non-suicidal self-injury (NSSI), suicidal ideation (SI), or suicidal self-injury (SSI). For each patient, only the primary diagnosis contributing to the admission was recorded. Data was sourced from electronic case summaries and emergency department records. Mean monthly percentage changes from baseline, obtained from Google Community Mobility Reports for six activity domains (retail and recreation, grocery and pharmacy, parks, transit, workplaces, and residences), were correlated with monthly hospitalization numbers using Pearson's correlation, to analyze the relationship between movement restrictions and hospital admissions. Statistical analyses were performed using IBM SPSS version 26.

In 2019, the highest admission rates were for substance use disorders, mood disorders, schizophrenia, anxiety disorders, and personality disorders. In 2020, overall admissions remained largely stable compared to 2019, with only a significant increase in suicidal ideation (SI) and a borderline increase in suicidal self-injury (SSI). There was also a non-significant increase in non-Maltese admissions, possibly indicating a disproportionate socioeconomic impact. In 2021, however, a substantial surge in admissions occurred across several diagnostic categories. Significant increases were observed in admissions for mood disorders, schizophrenia, personality disorders, anxiety disorders, and autism spectrum disorders (ASD), compared to both 2019 and 2020. Involuntary admissions also increased significantly. Presentations with NSSI, SI, and SSI continued to rise, with significant increases noted in SI and SSI compared to 2019 and increases in NSSI compared to 2019. The correlational analysis revealed strong positive correlations between total monthly admissions and community mobility in parks, transit, retail, and recreation, while a negative correlation was found with residential mobility. This suggests that as people spent more time in public places, admissions increased, and vice versa. The only significant change observed in 2020 was a decrease in admissions for childhood behavioural and emotional disorders.

The findings of this study reveal a nuanced picture of the pandemic's impact on mental health, with the most significant changes emerging in the second year. The initial relatively stable numbers in 2020 contrasted sharply with the substantial rise in admissions in 2021, indicating a delayed or long-term effect of the pandemic. This finding aligns with emerging literature showing the chronic impact of the pandemic on mental health, rather than simply the immediate effects. The study highlights the increased severity of cases in 2021, with higher rates of involuntary admissions and self-harm. The increased admissions for mood and anxiety disorders are consistent with existing research. However, the study uniquely shows a corresponding rise in psychotic disorders, personality disorders, and ASD, which weren't as noticeable in 2020. The increase in non-Maltese admissions in 2020 might reflect the impact of the pandemic on vulnerable populations. The significant correlation between hospital admissions and community mobility suggests that access to care was impacted by the pandemic, leading to delays in presentations. Although telemedicine was utilized, it might not have been enough to offset inequalities in access, particularly for older populations. This is further substantiated by the disproportionate increase in admissions for the 60-69 age group. The impact of the pandemic on specific vulnerable groups, including children and adolescents with ASD, who face unique challenges during lockdowns, is also discussed.

This study indicates that the long-term increase in psychiatric hospital admissions during the pandemic stemmed from a combination of the virus's direct effects, secondary impacts on psychological and socioeconomic wellbeing, and barriers to healthcare access leading to delayed presentations. The strong correlation between mobility and admissions further supports the role of healthcare access in the observed trends. Future pandemic response strategies should prioritize equitable access to mental health services and incorporate strategies to mitigate the long-term psychological consequences of restrictive measures.

The study's limitations include the possibility that the variation in pandemic responses across different regions may lead to varied mental health outcomes. The study also had limitations in its ability to fully capture outcomes across all age groups and to distinguish between new admissions and readmissions. Additionally, personality disorders may be underrepresented in the sample, potentially underestimating the true pandemic impact on this population. The focus on inpatient admissions might also obscure the broader spectrum of mental health challenges.