Morbidity Risk of Psychiatric Disorders Among the First Degree Relatives of Schizophrenia Patients in Taiwan

Abstract

This study aimed to assess the boundaries of the schizophrenia spectrum and whether inclusion of such phenotypes increases power for linkage analysis of schizophrenia. Participants were 234 first degree relatives (FDRs) of 94 schizophrenia probands in Northern Taiwan who completed a direct interview using the Diagnostic Interview for Genetic Studies (DIGS). Based on best estimate diagnosis, the morbidity risk in the relatives for schizophrenia was 2.5 percent (Weinberg's shorter method) or 3.9 percent (Kaplan-Meier estimate). Depending on the stringency of diagnosis, lifetime prevalence was 2.6 percent to 4.7 percent for schizotypal personality disorder, 3.4 percent to 8.6 percent for paranoid personality disorder, and 1.3 percent to 3.4 percent for schizoid personality disorder. These figures are significantly higher than the corresponding figures in the general population. However, none of the recurrence risk ratio for any spectrum that included both schizophrenia and a personality disorder (3.0 to 5.9) was greater than that of schizophrenia alone (9.3 to 14.4). Thus, including schizophrenia-related personality disorders in the spectrum did not increase power for linkage analysis of schizophrenia.

Morbidity profile of first-degree relatives of probands with schizophrenia: a comparison with mood disorder and healthy control

“…Adamson [7] and Gureje [8] reported morbid risks of schizophrenia of 6.70 and 4.12 %, respectively, among first-degree relatives of schizophrenia probands, while Gureje [8] also reported morbid risks for schizophrenia and mood disorder of 1.42 and 7.81 %, respectively, among first-degree relatives of mood disorder patients. Similar studies done in other cultures show morbid risk for schizophrenia among firstdegree relatives of schizophrenia patients ranging from 2.5 to 8.84 % [2,14].…”

“…With respect to specific diagnoses, Chang et al [2] reported a morbid risk for schizophrenia among firstdegree relatives of 2.5 % (Weinberg's shorter method) or 3.9 % (Kaplan-Meier estimate)-both figures higher than for general population. According to Maier et al [3], risk of schizophrenia among first-, second-and third-degree relatives of schizophrenia probands was 5, 3.1 and 1.5 %, respectively, compared to 0.8 % among controls.…”

Do Subjects at Clinical High Risk for Psychosis Differ from those with a Genetic High Risk? - A Systematic Review of Structural and Functional Brain Abnormalities

“…The risks for developing psychosis differ across these G-HR groups with monozygotic twins having a 40-50% concordance rate for the illness over lifetime [19] while other first-degree relatives of schizophrenic patients have approximately a 10-fold increased risk compared to non-relatives over lifetime [20] The retrieved studies have defined the increased clinical risk (C-HR) to psychosis according to the following criteria: (1) attenuated psychotic symptoms (APS) or (2) brief limited psychotic symptoms (BLIPS) or (3) genetic risk + social decline and prodromal symptoms, using Comprehensive Assessment of At-Risk Mental state (CARMS) [21] or Basel Screening Instrument for Psychosis (BSIP) [22]. Some groups have additionally added a certain combination of prodromal symptoms [10] or basic symptoms using Bonn Scale for Assessment of Basic Symptoms (BSABS) (for details see [14]).…”

Statistical validation of endophenotypes using a surrogate endpoint analytic analogue

“…To some extent, the results are not surprising. A previous analysis indicated that schizophrenia-related personality disorders, though part of schizophrenia spectrum, do not necessarily lead to a higher statistical power for future genetic analysis: the value of recurrence risk ratio by incorporating these personality disorders in the spectrum became lower than the corresponding figure for schizophrenia itself [Chang et al, 2002]. We might also be handicapped by the data structure (nuclear families only) and/or the sample size (91 schizophrenia families) of our study.…”