BDNF and depressive symptom measurement: However, these adjusted ROC curves could not effectively differentiate between individuals with suicide attempts and those without (p = 0.313).In a study by Khan et al. [14], the most suitable cutoff point for BDNF levels between individuals with suicidal depression and those without was determined to be 444.58 pg/ml, with a sensitivity of 68.7% and specificity of 78.1%.