TY  - JOUR
PY  - 2008//
TI  - Age at onset in Sardinian bipolar I patients: evidence for three subgroups
JO  - Bipolar disorders
A1  - Manchia, Mirko
A1  - Lampus, Simona
A1  - Chillotti, Caterina
A1  - Sardu, Claudia
A1  - Ardau, Raffaella
A1  - Severino, Giovanni
A1  - Del Zompo, Maria
SP  - 443
EP  - 446
VL  - 10
IS  - 3
N2  - OBJECTIVE: We studied age at onset (AAO) in order to assess the presence of different subgroups in a homogeneous genetic population, such as the Sardinian population. METHODS: Admixture analysis was applied in order to identify a model of separate normal distribution of AAO characterized by different means, variances and population proportions to allow for evaluation of different subgroups in a sample of 181 unrelated patients of Sardinian origin with bipolar disorder (BP) type I. The Mann-Whitney test was used to compare the means of AAO between subjects with a history of suicide attempts and subjects with no such history. RESULTS: The best-fitting model had three components with means (SD) of 18.1 (2.3), 24.3 (5.3) and 41 (11.5) years, comprising 36%, 39% and 25% of the sample, respectively. We obtained two cut-off points at 21 and 33 years, enabling the sample to be divided into three subgroups. The Mann-Whitney test revealed a difference between the mean AAO of subjects with a positive history of suicide attempts and that of subjects with no such history (p = 0.041). CONCLUSIONS: We found three AAO sub-groups in our sample of BP I patients of Sardinian origin. Our findings add further support to the hypothesis whereby AAO acts as a clinical marker of biological heterogeneity in BP.<p /> <p>Language: en</p>
LA  - en
SN  - 1398-5647
UR  - http://dx.doi.org/10.1111/j.1399-5618.2007.00572.x
ID  - ref1
ER  -