Irritability, Depression, Anxiety Scale – IDA
A self-report instrument designed to measure levels of depression, anxiety, and both inward and outward directed irritability.
Scale Development & Technical Details
Scale Overview
The Irritability, Depression, Anxiety Scale – IDA was developed by R. P. Snaith, A. A. Constantopoulos, M. Y. Jardine, P. McGuffin (1978). It is designed to measure Irritability, Depression, Anxiety. The scale is intended for use with Adults.
Scale Structure
This instrument consists of 18 items organized into 4 factors/subscales: Depression, Anxiety, Outward directed irritability, Inward directed irritability.
| Factor / Subscale | Items | N |
|---|---|---|
| Depression | 1,3,5,9,12 | 5 |
| Anxiety | 2,7,10,14,17 | 5 |
| Outward directed irritability | 4,6,13,16 | 4 |
| Inward directed irritability | 8,11,15,18 | 4 |
Response Format
Respondents rate each item using a custom response format.
Response anchors: 0 = Yes, definitely / Most of the time / Very good / Not at all, 1 = Yes, sometimes / Some of the time / Fairly good / Less than 1 hour, 2 = No, not much / Hardly ever / Fairly poor / About 1 hour, 3 = No, not at all / Never / Very poor / 2 hours or more.
The scale includes 12 reverse-scored items to reduce acquiescence bias.
Scoring
Items are scored by subscale, with each subscale sum representing a distinct dimension.
Total scores range from 0 to 15. Interpretation guidelines:
- Normal: 0 – 3
- Borderline: 4 – 6
- Elevated: 7 – 15
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of 0.89.
Administration
The scale is self-administered and typically takes approximately 5 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.