The Axial Diagnostic and Sensitive-to-Change for Depression Index: Diagnostic utility and use in studies of therapeutic evaluation

Abstract

Introduction. The authors develop a new rating scale for to measure its sensibility to the change of the intensity of the depressive symptoms under the effects of antidepressants drugs, and for to analyze the predictive validity of its total score. Designate it: The Axial Diagnostic and Sensitiveto-Change for Depression Index (ADSCDI). For this, use only seven nuclear items for the depression diagnosis (mood, interest, impulse/drive, pleasure, energy, daily job and different quality) without vegetative symptoms or anxious.

Methodology. The authors interview to 111 psychiatric outpatients attended consecutively in a Mental Health Center. Sixty were fulfilling the criteria for depressive episode of the ICD-10 and fifty and one were forming part of the group of control: psychiatric outpatients not depressed. They use for this a protocol of collection of data that contains the ADSCDI, where the patients indicate how are found on a Visual Analogical Scale in the one which quantify their answers in each item, the Hamilton Rating Scale for Depression of 17 articles (HRSD-17) and an Global Clinical Impression scale (GCI). Each depressed patient receipt the antidepressant treatment that better were adjusted to his clinical profile according to the psychiatrist that was trying to him. The depressed patients were evaluated a second time after thirty days of treatment.

Results. All the items of the ADSCDI perceive a change statistically significant in the intensity of the depressive symptoms (p=0.00). The total score of the ADSCDI, also, at same level of statistical significance that the total scores of the HRSD-17 and of the GCI (p=0.000). The ADSCDI interrelates high and significatively with the HRSD-17 as with the GCI (r=0.77 and r=0.73 respectively; p=0.00). Equally makes it with the average of the “proportion of improvement” that evaluates, with the one evaluated by the HRSD-17 and the GCI (r=0.74 and r=0.68 respectively; p=0.000). A cut-off of 39 offers the best predictive values for the ADSCDI respect to the clinical and the ICD-10 criteria for depression. With a sensibility of 0.97, a specificity of 0.76 (of 0.88 with psychiatric patients free of symptoms), a total probability of guessing right of 93% and a kappa reliability of 0.74. The results improve when the ADSCDI is used as external criterion. For this new operative diagnostic criteria (ADCD), a cut-off of 40 offers a sensibility of 1.00, a specificity of 0.96 a probability of guessing right of 99% and a kappa reliability of 0.96.

Conclusions. The ADSCDI offers sufficient concurrent validity with the HRSD-17 and the GCI. It can be considered a sensitive instrument to the change, with the advantage of containing, only, items that have shown be frequent, discriminant and predictives. The ADSCDI also is a good instrument to establish diagnostic of depression in the system ADCD/ADSCDI or in the ICD-10 one