In this study, the age of disease onset was 27.9 ± 0.19 y and age of their first hospitalization was 32.5 ± 0.2 y. Men were admitted more than women in the hospital. Less than half of inpatients with BID (Bipolar I Disorder) were married. Low educational level and high health insurance coverage and unemployment rate among them were considerable.
In Kupfer et al. study, 64.5 out of 3000 bipolar patients were women, and the mean age of onset was 19.8 years. Over 60% completed college and 64% were currently unemployed (
23). In Iran Hospital, the number of men beds was triple of women beds and this was the reason why the majority of our patients were men.
The data of this study were compared to Suppes et al. (
26), Lish et al. (
27), Regier et al. (
28) and Kogan et al. studies data (
18) (
Table 2). Our results are in conflict with western studies in a number of features, many of them may reflect cultural and society differences. As it is presented in
Table 2, the Iranian patients are characterized by a higher rate of unemployment, being single, having health insurance and lower rate of divorce and education compared to the other clinical samples.
| Variable | The present study | Suppes et al. (26) | Lish et al. (27) | Regier et al. (28) | Kogan et al. (18) |
|---|
| Sample size | 3000 | 261 bipolar disorders, 216 BID | 500 | 20000 | 1000 |
| Age at onset; y | 27.9 ± 0.19 | 22.16 ± 9.6 | | | 17.4 ± 8.6 |
| Age at first admission; y | 32.5 ± 0.2 | 29.46 ± 10.7 | | | |
| Gender | | | | | |
| Female | 33.9 | 56 | 63 | 57 | 58.6 |
| Marital status | | | | | |
| Married | 47.1 | 43 | 46 | 44 | 36.2 |
| Single | 41.9 | 31 | 25 | 22 | 35.2 |
| Divorced | 10.9 | 24 | 28 | 15 | 23.5 |
| Educational level | | | | | |
| Illiterate | 5.8 | | | | |
| Under diploma | 58.2 | | | | |
| Diploma | 27.6 | | 5 | 22.7 | 13.8 |
| University | 8.4 | | 55 | 28.6 | 82.3 |
| Health insurance status | | | | | |
| No health insurance | 7.4 | 14 | | | |
| Employment status | | | | | |
| Unemployed | 47.6 | 6 | | | 22.0 |
| Index episode | | | | | |
| Mania | 65 | | | | 26.1 |
| Depressive | 30.3 | 25 | | | 52.0 |
| Mixed | 2.7 | 48 | | | 21.0 |
| Others | 1.9 | | | | 0.9 |
a Data are presented as Mean ± SD, or (%).
High rates of unemployment, lower education and being single perhaps are due to the stigma and insufficient social resources for patients with mental disorders in Iran. Also, it could be due to the higher prevalence of these attributes in the Iranian general population than western populations. Furthermore, Iran Hospital is located in a low socioeconomic region, outside of Tehran and the economic and educational properties of the patients of this study could not be generalized to all the psychiatric inpatients of Iran.
Age of onset and the first admission were also higher than those of other studies. Overlooking the symptoms of mania, lack of insight into manic symptoms, and recall bias could be the reasons of higher age of onset. In addition, misdiagnoses and the stigma as a barrier to on time hospitalization may be the causes of higher age of first admission.
In the majority of the patients, the disorder had begun with manic phase (
24,
25), which is consistent with the data of previous Iranian studies on bipolar patients and in contrast to studies in western countries. Some reasons such as more acceptability and tolerability of depressive symptoms rather than behaviorally disruptive manic episodes or overlooking of depressive symptoms by mental health system professionals, patients, and their families could perhaps justify these results. Bed occupancy is high in Iran Hospital. Hence, it is possible that patients with mild form of disease, especially depressed patients have not been admitted regarding the hospital priority for admitting aggressive manic patients. Depression was higher in the women and the number of female beds was one third of male beds. So it can be another reason that mania was the prominent feature of the disorder. Furthermore, all the other studies were carried out on outpatients and this could be another explanation for differences of types of episodes. According to Jablensky study on severely ill hospitalized patients in Germany, (100 years ago) most “index” episodes were mania (
29).
In a study on hospitalized bipolar patients in Finland, the corresponding peak of 1-year incidences for a bipolar depressive episode occurred at the same age, was about half of that reported for mania (
30). On the other hand, in a study carried out on 8,889 psychiatric inpatients, 52.1 out of 1938 bipolar patients were men and almost 50% of patients were in depressed episode (
31). It seems that the findings in the literature are conflicting and difficult to reconcile, so it is highly recommended to design more studies aiming to investigate probable etiologies such as genetics.
Rate of health insurance shows the better medical insurance coverage in Iran than western countries; however long waiting lists of state-run hospitals, increasing healthcare costs and poor insurance coverage of private outpatients’ services should not be disregarded.
Retrospective method and lack of a standard diagnostic instrument were the limitations of this study. In addition, this study was conducted based on the data from medical records of inpatients and lacked appropriate assurance of quality and consistency of collected data. However, considering that the hospital was a university affiliated residency training center and the diagnosis was based on DSM-IV-TR criteria, authors would assume acceptable requirements for using those findings. It is highly recommended to design future outpatient studies in order to review clinical features of bipolar outpatients and compare them with studies in other countries.