The Cross-Cultural Differences in Symptoms of Schizophrenia: A Systematic Review

Abstract

The symptoms of schizophrenia may vary across cultures largely in terms of positive symptoms. Culture-specific symptoms can affect treatment or assessment processes, therefore it is considered crucial to determine these differences in positive symptoms, especially hallucinations. In this study, we aim to systematically examine and understand these cultural differences in hallucinations within the context of schizophrenia. Using the related keywords in different databases, we identified 465 articles. The systematic review included 21 articles published between 1975 and 2016 that met the eligibility criteria. After systematically reviewing the articles, it appears that auditory hallucinations were generally the same across cultures, but visual hallucinations were more common in Africa, Asia, the Middle East, and the Caribbean than in Europe and America. In some cultures, religious and cultural beliefs were influential in terms of the content of hallucinations. While the order of frequency types of hallucinations seen in schizophrenia across cultures seems to be relatively similar, the frequency of hallucination types may differ across cultures suggesting the pathofacilitative effects can partly play. Furthermore, the pathoplastic effect and social kindling hypotheses may explain the content differences by identifying that culture influences the expression of symptoms at the content level. Although studies have limitations, some of which need to be read carefully since they may not fully represent cultural samples, it was expected that this study would contribute to a better understanding of how culture affects hallucinations as well as highlight the treatment and assessment options that might be useful for clinicians.