Abstract
Czech version of STDI involves 20 items, 10 items measure Depression State (S-Dep), and 10 items measure Depression Trait (T-Dep). Both scales involve 5 items measuring absence of depression, Euthymia, and 5 items measuring presence of depression, Dysthymia.
Each item was translated several times, and backward translated to English. The author of the original STDI selected 61 backward translated items that semantically correspond to the tested constructs.
These items were administered to 268 secondary school and university students (172 female, 96 male). The factor analysis has shown two factors of state and trait for both Dysthymia and Euthymia.
The Czech version of STDI corresponds to 3 criteria: 1) Items are not visibly similar. 2) Each item of the Czech STDI corresponds to exactly one item of the original STDI. 3) Factors including items that fulfill criteria 1) and 2) and reach the highest Cronbach's Alpha levels have been chosen for Czech version STDI. The Alpha of S-Dep is 0.84, for T-Dep is 0.86.
A concurrent validity is approximately the same as in the original STDI. The Czech version of STDI is available for research purposes only.