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Keywords:

  • early diagnosis;
  • health care;
  • immigrants;
  • minority groups;
  • psychosis

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Aim

The aim of the study was to explore if patients with migration and/or ethnic minority background have longer duration of untreated psychosis (DUP) than patients from the reference population, and in case to what extent this was best explained by ethnic minority status or migration background, including age at migration.

Methods

Four hundred sixty-two first-episode patients were included. The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I Disorders was used for diagnostic purposes. Patients were interviewed about migration history and ethnicity using structured questionnaires.

Results

Being part of an ethnic minority group had a trend-level significance, and migration after the age of 6 had a statistically significant association with prolonged DUP.

Conclusions

Age at migration has a moderate, but statistically significant effect on DUP. The findings indicate migrating after school start is associated with a longer DUP in immigrant populations.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Being an immigrant or being part of an ethnic minority population, clearly distinct from the majority population, is well-established risk factors for psychotic disorders.[1, 2] Ethnic minority status and a migrant background also have implications for pathways into the health-care system and, thus, have possible associations with the duration of untreated psychosis (DUP).[3-5] A long DUP has consistently been shown to be associated with poorer outcome.[6, 7] An insidious mode of onset,[8] early age at onset,[9] poor premorbid adjustment and a diagnosis within the schizophrenia spectrum,[10] living in highly urbanized areas[4] or lack of close family relations, and infrequent family and social contacts have previously also been found to be associated with long DUP.[11-13]

Findings regarding DUP's relation to ethnic minority status and migrant background are however ambiguous. A Dutch study focusing on ethnic minority status found significantly longer DUP in minorities than in the reference population.[3] In the UK-based AESOP (Aetiology and Ethnicity in Schizophrenia and Other Psychoses) cohort, black African patients had shorter DUP than the reference population,[5] whereas no ethnicity-based differences in DUP was found in a Canadian study.[14] A predominantly African-American group with economic disadvantages from the USA had significantly longer DUP than other patients.[15] A second Dutch study, focusing on migration background, found longer DUP in first-generation immigrants.[4]

In a non-systematic review, immigrants tended to be unfamiliar with the local health-care system in terms of navigating services needed.[16] Patients who recently migrated will probably have even less knowledge about local health service access. To what extent cultural beliefs about mental disorders and right to access health services may influence help-seeking behaviour could also vary based on local service organization. The effects on DUP of ethnic minority status versus migration can be difficult to evaluate as ethnic minorities (EMs) often have a migration background. However, some EMs have a long local history whereas other groups have migrated from countries that resemble the majority and do not appear as EMs.

The current study is based on a large, first-episode sample from a catchment area-based health-care system. Of the catchment area population 19.1% are first- or second-generation immigrants, and 12.0% are EMs.[17]

Health service access is for practical purposes without costs for the patients, making it possible to disentangle the effects of migration and ethnic minority status from the effects of economic disadvantage.

We aimed to explore if patients with migration or ethnic minority background have longer DUPs than patients from the reference population, and, in case, we want to explore if this is best explained by ethnic minority status or migration background, including age at migration (before or after start of compulsory schooling at age 6).

Method

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Participants

Participants were recruited consecutively between 2004 and 2012 from in- and outpatient psychiatric units in the catchment area of the five major hospitals in East Norway, as part of the larger Thematically Organized Psychosis Study, approved by the Regional Committee for Medical Research Ethics. Our research methodology conformed to the Code of Ethics of the World Medical Association, Helsinki Declaration.

A total of 462 patients with reliable DUP measurements gave informed consent to participate: 250 with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) schizophrenia spectrum disorders and 212 with other psychotic disorders. A pronounced cognitive deficiency (IQ below 70), severe brain damage or the inability to speak a Scandinavian language, were exclusion criteria.

The participants included 312 non-immigrants (NI) and 150 (32.5%) immigrants (defined as foreign born or children of foreign born); 50 (10.8%) originated from Europe, North America and Oceania, and were categorized as migrants from the ethnic majority (MM); 100 (21.6%) had cultural background from Africa, Asia (including Arabic countries) or Latin America, and were categorized as EMs.

Assessments

All patients were assessed by trained clinical research personnel. The Structured Clinical Interview for DSM-IV Axis I Disorders was used for diagnostic purposes. Interrater reliability had an overall kappa score of 0.77 (95% confidence interval: 0.60–0.94).[18] Premorbid adjustment was assessed by the Premorbid Adjustment Scale (PAS).[19] Patients were interviewed about migration history and ethnicity, and data were also collected about education, occupation, housing and marital status. DUP was defined as the period of time from first psychotic symptom (i.e. four or more on Positive and Negative Syndrome Scale for Schizophrenia[20] items P1, P3, P5, P6 or G9 for 1 week), until adequate treatment (i.e. admission to hospital or antipsychotic medication in adequate doses).

Statistics

Statistical analysis was performed using IBM Statistical Package for the Social Sciences 20 (IBM Corp., Armonk, NY, USA). The level of significance was preset to P < 0.05 (two tailed). One-way analyses of variance with Tukey's post hoc tests were used for group-wise comparisons of continuous variables and chi-square test for categorical variables. Bivariate correlations were used to explore association between background variables and DUP, migration background and ethnic minority status, respectively. Hierarchical, blockwise and multiple regression analyses were used to assess the influence of migration background and ethnic minority status on DUP, after controlling for possible confounding variables, with premorbid academic and social adjustment in the first block; age at onset and diagnosis in the second; and ethnic minority status, migration and age at migration, respectively, at the last step. PAS and DUP measures were skewed and logarithmic transformed for the analyses. Total years of education and PAS academic score were correlated (r = −0.41, P < 0.001) and could not be entered simultaneously. Because differences in total years of education could be based on different school systems in countries of origin and thus dependent on migration status, the PAS score was preferred in the final model.

Age and age at onset was highly correlated (r = 0.86, P < 0.001) in this first-episode sample, and age at onset was kept in the final analyses. All non-significant variables (including close family relations and gender) were taken out of the final models. Only the final models are presented in the paper. Missing values (three for age at migration and nine for PAS) were replaced by group mean. The variable age at migration was dichotomized to migration before or after the age of 6, that is, start of school. Model fit was evaluated through examination of residual plots.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

The EM group had poorer academic adjustment than the MM group, and shorter education than both the MM and NI groups (Table 1). Age at onset, premorbid social and academic adjustment, and schizophrenia diagnosis were all significantly associated with DUP (Pearson's r = −0.17 to 0.25; P < 0.001). There were no significant associations between premorbid academic or social adjustment and EM status (Pearson's r = 0.05 and −0.03, respectively; P = 0.48). In the multivariate regression analyses, age at onset, premorbid social and academic adjustment, and schizophrenia diagnosis retained a significant influence on DUP. In the last block, neither migration per se (P = 0.10; data not shown) nor being part of the EM group (P = 0.07) had a statistically significant association with DUP (Table 2). Migration after the age of 6 (Table 3) had a statistically significant association with DUP.

Table 1. Demographic information for total sample and for immigration based subgroups
 NI (n = 312)Immigrants (n = 150)anova with Tukey's post-hoc test 
MM (n = 50)EM (n = 100)
Mean (SD)Mean (SD)Mean (SD)
  1. a

    High score means low function.

  2. b

    Living with spouse or parents.

  3. anova, analysis of variance; EM, ethnic minority; MM, migrant majority; NI, non-immigrants; SD, standard deviation.

Age27.0 (8.2)28.1 (9.4)27.2 (7.8)P = 0.64 
Age at onset24.0 (8.3)23.5 (10.0)24.5 (7.3)P = 0.77 
Premorbid academic adjustmenta1.14 (0.46)0.98 (0.45)1.17 (0.43)P = 0.04EM > MM (P = 0.05)
Premorbid social adjustmenta0.92 (0.57)0.93 (0.56)0.88 (0.59)P = 0.76 
Total years of education13.1 (2.5)13.1 (3.1)11.5 (2.9)P < 0.001EM < MM, NI (P = 0.003/0.001)
 n (%)n (%)n (%)Chi-square 
Preschool age at migration29 (58.0)47 (47.0)P = 0.20 
Male184 (59.0)28 (56.0)65 (65.0)P = 0.47 
Schizophrenia diagnosis163 (52.2)25 (50.0)62 (62.0)P = 0.19 
Close family relationsb148 (47.4)17 (34.0)54 (54.0)P = 0.07 
Table 2. Hierarchical blockwise multiple regression model of variables predicting duration of untreated psychosis including ethnic minority status (EM) variable
 Unstandardized coefficientsStandardized coefficients95% confidence interval for B
BSEβtSig.LowerUpperR2 change
  1. Total adjusted R2 = 0.112; total model F = 12.649, sig. = 0.000.

  2. SE, standard error.

Block 1:        
Academic0.3230.1890.0801.7140.087−0.0470.694 
Social0.3800.1470.1202.5760.0100.0900.6700.057
Block 2:        
Age at onset−0.0310.010−0.140−3.0460.002−0.050−0.011 
Schizophrenia diagnosis−0.6930.164−0.192−4.2300.000−1.016−0.3710.059
Block 3:        
EM0.3550.1930.0811.8370.067−0.0250.7340.007
Table 3. Hierarchical blockwise multiple regression model of variables predicting duration of untreated psychosis including preschool age at migration variable
 Unstandardized coefficientsStandardized coefficients95% confidence interval for B
BSEβtSig.LowerUpperR2 change
  1. Total adjusted R2 = 0.117; total model F = 13.254, sig. = 0.000.

  2. SE, standard error.

Block 1:      
Academic0.3810.1880.0952.0210.0440.0100.751 
Social0.3810.1470.1202.5940.0100.0920.6700.057
Block 2:      
Age at onset−0.0330.010−0.150−3.2540.001−0.052−0.013 
Schizophrenia diagnosis−0.6840.163−0.189−4.1870.000−1.005−0.3630.059
Block 3:      
Preschool age at migration−0.5380.219−0.110−2.4600.014−0.968−0.1080.012

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

The main finding of this study is that migration after the age of 6 and ethnic minority status were associated with a longer DUP in a catchment area-based public health-care system. Consistent with previous studies,[10] we also found that poor premorbid adjustment, low age at onset and diagnosis within the schizophrenia spectrum were associated with a longer DUP.

We propose that migration after school start may influence knowledge about the local health-care system and thus help-seeking behaviour in immigrants' low levels of literacy in general adds barriers to using and assessing mental health services,[21] and low levels of mental health literacy in particular have been found to delay treatment for depression in immigrants.[22] Low mental health literacy may thus partially mediate the association between low premorbid academic adjustment and shorter education with longer DUP, two characteristics that were significantly more compromised in EM. This should be the focus of future research concerning the treatment and outcome of psychotic disorders in immigrant groups. Another important factor may be culturally rooted stigma of visiting a psychiatrist,[23] which could explain why ethnic minority status appears to have an effect on DUP regardless of age at migration.[3, 4]

Strengths and limitations

We did not include patients who needed an interpreter, and we may have missed very recent immigrants in our sample. We cannot rule out that other factors associated with both EM status and help-seeking behaviour, such as language skills, could confound the DUP results; however, all participants in our sample did speak a Scandinavian language fluently. The rate of EMs in the current sample is at the same level as in the general population, and previous findings of equal rates of admissions[24] and consultations[25] because of mental illnesses in both EMs and the reference population in this catchment area indicate that findings can be generalized.

Conclusion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Age at migration has a moderate, but statistically significant effect on DUP. The findings indicate that migrating after school start is associated with a longer DUP in immigrant population.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

The study was supported by the Research Council of Norway, Regional Health Authority South Eastern Norway, Oslo University Hospital and the University of Oslo. We declare that none of the authors are financially involved or affiliated with any organization that may benefit from these findings. We thank all participants to the TOP study for their contribution as well as all of our colleagues who have recruited and interviewed participants to the study.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Method
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References