To the best of our knowledge, this is the first full-sample data study that describes the gender distribution of psychiatric outpatients in 3 general hospitals in China, which provides data support for the needs of different genders in clinical practice for mental health diagnosis and treatment. In this study, women were more common in psychiatric clinics in general hospitals, and the difference in the male-to-female ratio had increased. Besides, women are more common in all age groups, especially in the group aged 50–64 years, as well as in almost of diagnostic categories except the category of mental and behavioral disorders due to psychoactive substance use. Patients with 19–34 years group and anxiety disorders, undetermined diagnosis categories showed an increased proportion of women.
Women suffering from mental disorders were more common in psychiatric clinics in general hospitals. We found an increased proportion in women from 2019 to 2020 at the level of total patient visits, number of patients and number of first-visit patients. The results were obviously contrary to the census data in China, which reported that there were more males than females and the male-to-female ratio reached 1.05:1[17]. Previous studies didn’t reach a consensus on gender distribution of mental disorders due to influencing factors such as the study population, social background, and type of mental disorders. Survey conducted on 2–18 years old children who were military dependents reported that mental health conditions were more common in boys, accounting for 57%-60% [18]. However, the Global Burden of Disease Study 2010 showed a heavier burden of mental disorders among women aged 10 years and over than men, while the burden of disease among men under 10 years old was heavier than that of women [19]. This study did not further stratify the population of 0–18 years old, and a more detailed stratified analysis of the age group could be carried out later. In the nationwide epidemiological sampling survey of mental disorders conducted in China[1], the male-to-female ratio in the sample population was 1:1.20(45.40% for men and 54.60% for women), while the male-to-female ratio in the population with mental disorders was 1:0.93(9.70% for men and 9.00% for women). Generally speaking, there was no significant difference in the prevalence of men and women in the mental disorders studied, but gender differences were shown in some specific disorders. For example, mood disorders were significantly more common in women, and substance use disorders and impulse-control disorders were significantly more common in men. The constituent ratio of psychiatric clinic visits in females in this study was significantly higher than that of males, which might be related to the diagnosis of mild and affective diseases predominated in psychiatric clinics of general hospitals, such as anxiety disorders and mood disorders, in which women had a higher prevalence than men [20–22]. In addition, a study in Australia found that men sought mental health services less frequently than women, with 5.33% of men and 10.2% of women receiving mental health services[23]. A study conducted in the Netherlands found that female patients with anxiety disorders in psychiatric clinics had higher scores on the self-rating scale than men [24]. The prevalence of mental disorders and the burden of disease has increased, while women feel worse about themselves and have more desire for treatment and expression, which may be related to the obvious gender differences in general hospitals. Furthermore, the negative effects of COVID-19 might exacerbate the risk of mental disorders in women and expand the gender difference, such as increased domestic violence against women[25], heavier economic burden, overuse of Internet and social media[26], which were the risk factors of mental illness. The significant gender gap indicates the great demand for women's diagnosis and treatment, which prompting the government and relevant departments and organizations to take targeted measures, especially to strengthen the care and attention to women's mental health. Besides, some male patients suffered from mental illness who have not sought medical treatment also need to be concerned.
The gender composition of all age groups was dominated by women, and the gender difference in the 50–64 age group was the highest at the level of person-time of diagnosis and treatment, patient number and first-visit patient number, followed by group aged 65 years and over at the level of total patient visits and patient numbers. However, at the level of first-visit patient number, the gender difference in the 19–34 age group ranked second among all age groups. Besides, 0–18 and 19–34 age group showed a significantly increased female proportion in 2020. The widening of the gender gap in the 19–34 age group might be related to the following reasons. With the increasing awareness of gender equality, women’s social status had gradually improved. Women played more roles in social work and also bore a lot of pressures. For example, they should not only take care of their families, but also bear the pressure of financial resources. Georgia Balta et al [27] analyzed the factors that affected women's mental health from the perspective of social background, including deep-rooted male dominance, the values of thinness for beauty, marital conflicts and so on, all of which had a negative impact on women's mental health. People aged 19–34 years are under the pressure of work, marriage, family and other aspects, and they receive more stress. The COVID-19 pandemic brought higher risk to anxiety and depression as well[28], which might be related to the widening of the gender gap in the 19–34 age group. This was correspondent with a previous study from Austria, which reported that people under 35 years old and female sex showed more mental health symptoms during COVID-19[29].
The proportion of male patients with mental and behavioral disorders due to psychoactive substance use was significantly higher than that of female patients, but in the other diagnostic categories the proportion of female patients was higher. This result was basically consistent with the gender distribution in the previous epidemiological surveys of the prevalence of mental disorders. A meta-analysis on the prevalence of common mental disorders (mood disorders, anxiety disorders, and substance use disorders) showed that women had a higher lifetime prevalence of mood disorders and anxiety disorders, while men had a higher lifetime prevalence of substance use disorders [30]. The data of Global Burden of Disease Study 2016 showed that there was no gender difference in the prevalence of schizophrenia, but the exception was that the prevalence of male was lower than that of female in China, and the prevalence of dementia in women was higher than that in men [31, 32]. A survey on the prevalence of sleep disorders among non-psychiatric outpatients in 4 general hospitals in China found that the prevalence of women was higher than that of men(23.2% for women and 20.1% for men)[10]. As there are a large number of diagnoses in the categories of other mental disorders and undetermined diagnosis, further stratified analysis and longitudinal follow-up can be carried out to explore the development of diseases with undetermined diagnosis. The female proportion of anxiety disorders and undetermined diagnosis categories was significantly increased in 2020 at all three levels. Several previous studies had illustrated high rates of anxiety and depression symptoms[13, 33]. But in this study it was interesting to find that female proportion in mood disorders didn’t show similar trend at all three levels.
Our study has several limitations. First, this is a retrospective study, which lacks of comprehensive longitudinal follow-up investigation. Due to the large number of outpatients and the limited time for each patient to receive diagnosis and treatment, it is possible that the outpatient diagnosis records involved are not completely accurate. Although electronic medical records have been popularized in recent years, the diagnosis basis of each hospital is not completely consistent and homogeneous, so there may be some errors in the classification of diagnosis. In addition, this study used monism, did not analyze the comorbidity of mental disorders, there may be some errors in the gender distribution of each diagnosis. And this study only described and compared the diagnostic categories, but did not further analyze the diagnostic subclasses. More targeted data analysis can be carried out in the future.