Irritability, Depression, Anxiety Scale – IDA
A self-report instrument designed to measure symptoms 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 = No, not at all / Never / Not at all, 1 = No, not much / Rarely / Hardly ever, 2 = Yes, sometimes / Occasionally / Some of the time, 3 = Yes, definitely / Sometimes / All the time.
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 (for 4-item subscales: Outward/Inward Irritability): 0 – 3
- Borderline (for 4-item subscales: Outward/Inward Irritability): 4 – 6
- Abnormal/Elevated (for 4-item subscales: Outward/Inward Irritability): 7 – 12
- Normal (for 5-item subscales: Depression/Anxiety): 0 – 5
- Borderline (for 5-item subscales: Depression/Anxiety): 6 – 8
- Abnormal/Elevated (for 5-item subscales: Depression/Anxiety): 9 – 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.