Research suggests that the contents of delusions in schizophrenia are influenced by culture and social environment. However, few studies have investigated the chronological change of such delusions within a society. To investigate specifically the changes in the persecutory delusions of schizophrenia that have occurred over time, we compared the nature of the persecutors and their persecutory behaviors among inpatients with schizophrenia.
All admissions to the psychiatric unit of Hanyang University Guri Hospital with discharge diagnoses of schizophrenia during two different five-year time frames (1996-2000 and 2006-2010) were reviewed. From their inpatient medical records, we investigated the descriptions of persecutors and their persecutory behaviors in the delusions of 124 patients (54 in the1990s and 72 in the 2000s).
Overall, persecutory behaviors and nature of persecutors in the delusions of schizophrenia did not differ between the two time frames. However, subgroup analysis revealed that in women but not in men, rejection as a persecutory behavior was significantly higher in the 1990s (p<0.05).
The ten-year time interval may be too short to find significant changes in delusional content in general. However, our additional finding in women may be a result of the tremendous change in status of Korean women during the last decade.
Schizophrenia is a chronic psychiatric illness characterized by psychotic symptoms such as delusions and hallucinations.
Current literature indicates that the phenomenology of delusions and hallucinations in schizophrenia is influenced by the culture of the patient.
Most studies in this area have examined the cross-cultural difference between western and eastern countries or among different ethnic groups within a nation. Relatively little attention has been paid to longitudinal changes in delusions within a culture. Klaf and Hamilton
While these pioneering studies indicate that changes in the content of delusions and hallucinations tend to parallel societal and cultural changes, several methodological issues must be addressed before these findings can be generalized. For one, the studies assessed the content of delusions using different instruments so that results are difficult to consolidate meaningfully. They also examined a wide range of vaguely defined delusion types, rather than conducting a more focused investigation of a specific type of delusion. Further, in these studies, the time periods covered ranged from 50 to 100 years, which does not address short-term changes or more serial trends. One exception is a study by Uh and Kim
From the 1980s to the 1990s, South Korea underwent very rapid transformation from a traditional, politically oppressive and economically developing country to a westernized, individualistic, democratic society with economic wealth. This rapid evolution provides a good opportunity to study how such social changes may be reflected in the delusions of schizophrenia.
All subjects in this study were inpatients in Hanyang University Guri Hospital, Gyeonggi, South Korea, who were discharged during the period from 1996 to 2000 or from 2006 to 2010. The medical records of patients with a discharge diagnosis of schizophrenia based on ICD-10 were considered eligible for inclusion in the study. Exclusion criteria were mental retardation, neurological disorder, serious medical condition, and those with whose cultural background was not South Korean. Eight patients were admitted both in the 1990s and the 2000s were excluded. The medical charts of twenty four patients (19%) in 1990s were lost and could not be accessed. Thus, the number of eligible patients was 104 in the 1990s and 143 in the 2000s. Of these participants, 69 (66%) and 103 (72%) respectively had persecutory delusions. Further, to rule out the possible effects of sustaining delusional content from the first to the second time frame, we exclude patients whose duration of illness (i.e., time passed after onset of positive symptoms such as delusion or hallucination) was more than five years. This created a final sample of 54 patients from the 1990s and 70 from the 2000s.
After approval of the institution's research ethics review board was obtained for this study, each patient's records were evaluated by the first author using a checklist to categorize the delusions. The checklist contained a classification of persecutors developed by Uh and Kim
Types of persecutors on the checklist included political figures (police, secret service agents, military or communist party leaders), family and relatives, coworkers or friends, neighbors, unidentified persons, supernatural beings and religious leaders, millionaires, medical personnel, teachers, creditors, and members of the communist army.
To measure inter-rater reliability of the checklist, the first and second author each completed the checklist for a non-random sample of 30 participants' records. The kappa when comparing the ratings for persecutory behaviors and the nature of persecutors were 0.67 and 0.91, respectively.
For all the categorical variables that included persecutors and persecutory behaviors, we used the Chi-square test or Fisher's exact test to compare the distributions for the two time-periods. For the continuous variables that were not normally distributed, the Mann Whitney test was conducted to compare between groups. All the data were analyzed with SPSS for Windows Version 18 and statistical significance was set at the level of 0.05 bidirectionally.
Compared with patients in the 1990s, those in the 2000s were significantly older [mean 33.1 (SD=8.1) vs. 28.3 (SD=11.2), p=0.017].
Overall, the most common persecutory behaviors in the two groups were chasing or capturing (33%), angry thoughts (27%), physical attack (26%), critical remark (20%), and murder (18%). The most commonly described persecutors were unidentified persons (69%), followed by family or relatives (17%), coworkers or friends (14%), and neighbors (14%). No cases described a persecutor in the category of creditor.
Our analysis indicated that there were no significant differences in persecutory behaviors or persecutors in the records of the patients in the 1990s and 2000s, when taken as a whole (
The main finding in this study was that rejection or refusal was the only significantly different category of persecutory behaviors between the delusions of schizophrenic patients of the 1990s and 2000s. This finding was seen in women but not in men. Furthermore, no case reported rejection or refusal as a persecutory behavior in the 2000s. Similarly, a decrease in frequency of rejection or refusal was noted in a previous study by Uh and Kim,
A great improvement in the social status of women with movement toward equality for the sexes has been occurring since the early 1990s.
Uh and Kim
Moreover, this view is supported by our finding that only about 5% of patients reported political persecutors in our groups. This percentage was 28% in the early 1980s and 12% in the early 1990s, in a previous study.
Studies from politically stable, developed countries such as England, America, and Japan have compared time frames of 50 to 100 years, in order to find changes in delusional content.
To our knowledge, no other study has examined chronological changes in schizophrenic delusions of persecution; however, our findings are consistent with other studies that have found that sociopolitical changes seem to affect delusional themes. For example, Skodlar et al.
Collectively, the findings of the current and earlier studies show that sociocultural changes in the environment seem to affect how patients with schizophrenia perceive their external world, which in turn influences how they interpret their inner psychotic experiences.
There were several limitations of this study. First, it was based on data from retrospective chart reviews, and future research may benefit from the development of an interview instrument to better assess the content of persecutory delusions. Second, the coding system used for persecutory behaviors was originally developed for dream analysis. Although we believe these categories fit well to persecution content, validity has not been examined for this application. Third, patients in this study were acute inpatients in a tertiary referral center, thus limiting generalization to more chronic populations. An outpatient sample may have been more diverse and representative, but a concern exists for the quality and quantity of information in their charts. Fourth, the sample sizes for the variables with lower frequencies in the subgroup analysis were often too small. For example, "rejection or refusal" had a statistical significant result, but with only three cases in the category it cannot be seen as clinically meaningful.
Despite these limitations, our study is one of only a few that have examined changes with time in the delusional content of schizophrenia. Our study provided support to the theory that the culture and expectations in a society influence the nature of the delusions that are formed and maintained in it.
In conclusion, we found that the a specific type of content in the delusions of patients with schizophrenia, i.e., persecutors and their behaviors, changes in accordance with societal transformation, supporting the view that delusional content of schizophrenia reflects the sociocultural characteristics of the time. With this implication in mind, clinicians can better understand the meaning of psychotic symptoms in schizophrenia, which can help them to facilitate engagement and patient co-operation when dealing with delusions in therapy.
Baseline characteristics of participants with schizophrenia in the 1990s and 2000s (N=124)
*Mann-Whitney U, †household income in US dollars
Persecutory behaviors in delusions of schizophrenia in the 1990s and 2000s
Statistical analysis used either Chi-square or Fisher's exact test. *by Fisher's exact test
Nature of persecutors in delusions of schizophrenia in the 1990s and 2000s
Statistical analysis used either Chi-square or Fisher's exact test. *by Fisher's exact test