METHOD: We translated the TCI into Mandarin and had a non-psychiatric sample of Malaysian Chinese subjects complete the TCI at baseline and at a 1-month retest, with subsets completing English or Mandarin versions alternatively or on both occasions. Analyses examine the TCI factor structure and any impact of language and culture on TCI scoring.
RESULTS: We identified age, gender, occupation and language effects on TCI scale scores. Test-retest reliability was high and not compromised by language. Scale internal consistency was also high. Factor analyses of separate sets of TCI scales corresponded strongly to the structure identified in the TCI development studies.
CONCLUSION: The results indicate that TCI is likely to have applicability to Chinese subjects, and argue against properties being constrained by the English language or by western culture.
METHOD: Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density.
RESULTS: There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001).
CONCLUSION: A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.
METHODS: Latent class analysis (LCA) was employed to model the co-occurrence of PTEs in two school samples of adolescents from India (n = 411) and Malaysia (n = 469). Demographic correlates (i.e., sex, age, household composition, parent education) of the latent classes and the association between latent class membership and probable diagnosis of posttraumatic stress disorder (PTSD) were examined.
RESULTS: The LCA identified three latent classes for the Indian sample: 'Low Risk - moderate sexual trauma', 'Moderate Risk', and 'High Risk'. Similarly, three classes were also identified for the Malaysian sample: 'Low Risk', 'Moderate Risk', and 'High Risk'. Membership of 'Moderate Risk' was associated with male sex in both samples, and with older age and lower levels of parental education attainment in the Malaysian sample. No correlates of 'High Risk' class were identified in either sample. Membership of the 'High Risk' class was significantly associated with probable PTSD diagnosis in both samples, while membership of the 'Moderate Risk' class was associated with probable PTSD diagnosis in the Malaysian sample.
CONCLUSION: Findings from this study correspond with Western studies indicating co-occurrence of PTEs to be common and to represent a salient risk factor for the development of PTSD.