Scale Introduction

Carroll Rating Scale for Depression (CRS) free online test. The CRS is primarily used for comparison with the Hamilton Depression Rating Scale, because the Hamilton Depression Rating Scale is a clinician-rated scale that requires assessment by a professional. In order to understand whether the results obtained from self-rating and clinician-rating are consistent or to what extent they differ, the CRS can be used, as there may be a certain discrepancy between what a clinician perceives and what one perceives oneself.

The 52 items of the CRS primarily target each symptom corresponding to the Hamilton Depression Rating Scale. In the Hamilton Depression Rating Scale, some symptoms are rated on a scale of 0-4, while others are rated 0-2. Correspondingly, similar symptoms in the CRS also have 4 or 2 descriptors, with graded severity. Since the 52 items of the CRS correspond to all the symptoms of the HAMD, from this perspective, the Carroll Rating Scale (CRS) can be seen as the self-rated version of the Hamilton Depression Rating Scale.

Reliability and Validity Testing

Carroll et al. (1981) reported survey data based on three different samples:

• Group 1 (General Population): 119 employees of the University of Michigan Medical Center, aged 18-64, with subjects covering different socioeconomic strata.
• Group 2 (Endogenously Depressed Patients): 200 patients, aimed at studying the relationship between CRS scores and clinicians' global impression of depression severity. A total of 1191 examinations were conducted.
• Group 3 (Inpatient Psychiatric Patients): 278 inpatients with varying diagnoses, aimed at comparing the relationship between the CRS, BDI (Beck Depression Inventory), and HRSD (Hamilton Rating Scale for Depression).

Internal Consistency

The authors reported a split-half reliability coefficient of 0.87, with item-total correlations ranging from 0.05 to 0.78 (mean of 0.55). The correlation between the two split-half total scores and the scale total score was excellent (odd-numbered items r=0.79, even-numbered items r=0.96). In addition, the correlation between the 12 negatively worded items and the total score was 0.87, and the correlation between the 40 positively worded items and the total score was 0.98. Currently, there is no test-retest reliability data available for this scale.

Convergent Validity

The CRS was designed from the outset to be compared with the HRSD; therefore, many researchers have evaluated the convergent validity of the CRS by comparing the two scales. Carroll et al. (1981) published the correlation matrix between individual CRS symptom items and corresponding HRSD symptoms. Results showed a moderate correlation between CRS symptom category scores and the corresponding HRSD symptom scores (r values ranged from -0.06 to 0.73, mean = 0.60), suggesting that directly converting the HRSD into a self-rating scale may be somewhat crude.

However, the correlation between total CRS and total HRSD scores was high (r=0.80). Findings from other researchers are similar, with the lowest correlation between the two scale total scores observed in patients with bipolar endogenous depression (r=0.66). In addition to strong correlation with the HRSD, the CRS is also highly correlated with clinicians' global clinical impression of depression severity (r=0.67). The CRS also correlates highly with BDI total scores, with a correlation coefficient of 0.86 in psychiatric patients.

Discriminant Validity

Whether the CRS can correctly classify depression severity is related to the nature of the subject's depression. In non-endogenous depression, the correlation between clinician-rated HRSD scores and CRS self-rating scores is weaker. This may be because patients with non-endogenous depression (compared to those with endogenous depression) self-report more and more severe symptoms.

Furthermore, generally speaking, as the severity of depressive symptoms increases, the correlation curve between CRS and HRSD tends to diverge. That is, when depression worsens, the consistency between CRS and HRSD is weakened, suggesting that in certain patients, the meaning represented by CRS and HRSD may differ.

Overall, the CRS can serve as a useful supplement to the HRSD and global clinical impression, or even as a substitute in certain circumstances.

Score Interpretation

The total score ranges from 0 to 52, with higher scores indicating greater severity of depression.

Reference source: Introduction to the Chinese version of this scale and test link address https://toolonline.net/CRS