|
Symptom Checklist 90 (SCL-90)
Please note that this section is an archive (last updated in June 2006). [disclaimer]
Sections:
Overview |
Instrument Reviews |
Construct Overviews |
Book Compendium Reviews |
Internet Site Reviews
|
|
|
|
Practical Information
|
Instrument Name:
|
Symptom Checklist 90 (SCL-90)
|
Instrument Description:
|
The SCL-90 is a self-report clinical rating scale of psychiatric symptomatology. The instrument may be used in clinical and research settings. (Ref: 1) It is the precursor to the SCL-90-R, but is still used in research today. The SCL-90 does not have normative information, and most published psychometric research is performed for the SCL-90-R. It evolved from the Hopkins Symptom Checklist (HSCL), and its immediate precursor was the Symptom Distress Checklist (SCL). The first five dimensions of the SCL-90 are derived from these scales. (Ref: 2)
 It consists of 90 items total, with 83 items representing nine subscales: somatization (n=12 items), obsessive-compulsive (n=10 items), interpersonal sensitivity (n=9 items), depression (n=13 items), anxiety (n=10 items), anger-hostility (n=6 items), phobic anxiety (n=7 items), paranoid ideation (n=6 items) and psychoticism (n=10 items). Seven (7) additional items include disturbances in appetite and sleep. The authors suggest that factor structure be derived for each type of population. The SCL-90 also utilizes three global distress indices: Global Severity Index (GSI), Positive Symptom Distress Index (PSDI), Positive Symptom Total (PST). It may be used in screening or as a measure of patient progress.
|
Price:
|
Free (available through public domain in the developmental article)
|
Administration Time:
|
20 minutes (Ref: 1)
|
Publication Year:
|
1973
|
Item Readability:
|
Flesch-Kincaid 7th grade level score. Vocabulary was chosen by using the Thorndike-Lorge Word Book of 30,000 Words in order to achieve an overall basic verbal level. (Ref: 1)
|
Scale Format:
|
5-point Likert, ranging from “not at all distressing” (0) to “extremely distressing” (4).
|
Administration Technique:
|
Self-administered.
|
Scoring and Interpretation:
|
Raw scores are converted to T-scores and plotted on a profile showing the centile equivalent for each subscale. Subscale scores are found by summing item scores for the entire instrument and dividing by the total number of items on each subscale. The PST score is found by adding all items not scored zero. PSDI is found by dividing the grand total by the PST score. The GSI is found by summing the scores for the 90 items and dividing by 90.
|
Forms:
|
No information found.
|
|
|
Research Contacts
|
Instrument Developers:
|
Leonard R. Derogatis, Ronald S. Lipman and Lino Covi.
|
Instrument Development Location:
|
Johns Hopkins University School of Medicine, Baltimore, Maryland.
|
Instrument Developer Email:
|
No information found.
|
Instrument Developer Website:
|
No information found.
|
|
|
Annotated Bibliography
|
1. Derogatis LR, Lipman RS, Covi L. SCL-90: An outpatient psychiatric rating scale - preliminary report. Psychopharmacol Bull 1973 Jan;9(1):13-28. [PMID: 4682398]
 |
Purpose: To announce the development of the SCL-90 and provide details on nature, format and rationale. |
2. Derogatis LR, Rickels K, Rock AF. The SCL-90 and the MMPI: a step in the validation of a new self-report scale. Br J Psychiatry 1976 Mar;128:280-9. [PMID: 1252693]
|
Purpose: To examine the concurrent validity of the SCL-90. |
|
Sample: 209 symptomatic volunteers, mean age=39.5 years, 48% male and 52% female, 90% white and 10% black. |
|
Methods: Volunteers were administered the SCL-90 and the MMPI before participating in a drug trial. |
|
Implications: The SCL-90 showed high convergent validity with the MMPI on eight of the nine scales. |
3. Evenson RC, Holland RA. Factor analysis of the symptom checklist-90. Psychol Rep 1980 Jun;46(3 Pt 1):695-9. [PMID: 7394089]
|
Purpose: To verify the hypothesized factor structure of the SCL-90. |
|
Sample: 327 unselected outpatients at an urban state hospital clinic. 34% male, 95% white, 97% voluntary admissions and 99% new admissions, 31% never married and 27% divorced, 47% Protestant, 46% were 30 to 49 years old, 34% in clerical and service occupations, and median years of education=11.5. |
|
Methods: Patients completed the SCL-90 and results were factor analyzed. |
|
Implications: Ten descriptive factors were found. Anxiety was not a separate factor and only two of the items from the psychotic dimension formed a factor. |
4. Clark A, Friedman MJ. Factor structure and discriminant validity of the SCL-90 in a veteran psychiatric population. J Pers Assess 1983 Aug;47(4):396-404. [PMID: 6620108]
|
Purpose: To test whether the SCL-90 symptom subscales could be replicated in a VA sample. |
|
Sample: 442 veterans at a VA psychiatric outpatient clinic. Mean age=46 years, 95% male, mean years of education=11.8, average annual income=$10,480, 37% had a depression diagnosis. |
|
Methods: Veterans were given a structured interview and asked to complete the SCL-90. Principal components factor analysis was performed. |
|
Implications: Factor structure was different than those previously reported. Only 5 of the 9 dimensions emerged in this study. In the VA sample, the SCL-90 seems to measure a single distress factor rather than nine independent subscales. |
5. Magni G, Schifano F, de Leo D. Assessment of depression in an elderly medical population. J Affect Disord 1986 Sep-Oct;11(2):121-4. [PMID: 2948984]
|
Purpose: To evaluate depression in geriatric patients admitted to a general medical ward, and to test the reliability and efficacy of the Geriatric Depression Scale and the Depression Factor of the SCL-90. |
|
Sample: 220 medical geriatric inpatients (109 women and 111 men), mean age=75.93 years, majority were widowers or married, schooling levels were low, 152 subjects from urban areas and 68 from rural. |
|
Methods: Patients were administered the Geriatric Depression Scale and the SCL-90. Two psychiatrists made a DSM-III diagnosis after a clinical interview. The SCL-90 Depression factor score and Geriatric Depression Scale scores were compared. |
|
Implications: Both scales performed well in this sample, aiding a nonspecialist physician in screening of depression among elderly patients. |
6. Agbayewa MO. An exploratory use of the symptoms checklist-90 in a mixed geriatric study group. J Am Geriatr Soc 1990 Jul;38(7):773-6. [PMID: 2196305]
|
Purpose: To explore the validity of the SCL-90 in a geriatric sample. |
|
Sample: 44 geriatric subjects (30 attending a geriatric day hospital and 14 on wait for long-term care facilities) in Canada. 16 women and 28 men, mean age=78.5 years. The day hospital had been a veterans’ facility up to two years previously. |
|
Methods: Subjects completed the SCL-90, the Sandoz Clinical Assessment Geriatric (SCAG) scale was given by a research assistant, and the London Psychogeriatric Rating Scale (LPRS) was completed by the patient’s caregiver. |
|
Implications: The SCL-90 was not significantly different between the two groups of patients. It was correlated with the SCAG, but not the LPRS. It showed poor face validity and good internal consistency. Its use in older people may be limited due to lack of sensitivity to functional disability and care difficulty. |
|
|
top
|
Factors and Norms
|
Factor Analysis Work:
|
In the development of the scale, nine factors were found by varimax rotation. However, only four of the ten items deemed to represent “psychoticism” loaded on this factor. It was reported that those items would be adjusted, however, they were not. (Ref: 1)
A principal components analysis produced 18 factors. After rotation, a 12-factor solution was retained. The factors were: 1) Agitated Depression, 2) Somatic Concerns, 3) Phobic Fears, 4) Hostility, 5) Compulsions and Mental Blocks, 6) Psychotic Thinking, 7) Neurotic Guilt, 8) Eating Disturbance, 9) Suspicion and Mistrust, 10) Fainting, 11) Sleep Disturbance, and 12) Un-named. These 12 factors accounted for 60% of total variance, with the first factor accounting for nine times the variance of the second factor. All 90 items loaded >0.40 on the first principal component. Further, there was absence of an Anxiety dimension. The study reports that the author of the SCL-90 only found an Anxiety dimension in a sample of anxious neurotic patients and that the Anxiety dimension was the least stable. Other researchers have also not found an Anxiety dimension. Also, only two of the “psychotic” items clustered together. (Ref: 3)
In a veteran sample, a principal components analysis with orthogonal varimax rotation produced 15 factors, explaining 64.7% of the total variance. The first factor (Depression) accounted for 37.3% of the variance, while the second factor (Somatization) accounted for 4.6%. Factor three (Phobic Anxiety) explained 3.1% of the variance, Factor four (Sensitivity-paranoia) explained 3.0% and Factor five (Hostility) explained 2.1%. The match between these factors and the proposed dimensions was deficient (for example, the Depression factor contained items that were not included in the proposed Depression subscale). The Anxiety subscale did not form a distinct factor, and most items loaded on the Depression and Somatization factors. The Interpersonal Sensitivity and Paranoia subscales formed a single factor. (Ref: 4)
|
Normative Information Availability:
|
No information found.
|
|
|
Reliability Evidence
|
Test-retest:
|
Test-retest reliability ranges from 0.75 to 0.84. (Ref: 6, no time interval reported)
|
Inter-rater:
|
Inter-rater reliability ranges from 0.64 to 0.80. (Ref: 6)
|
Internal Consistency:
|
Reliability estimates are available for each scale of the SCL-90: (Ref: 2)
| Scale
|
Coefficient
|
| Anxiety
|
0.85
|
| Depression
|
0.90
|
| Hostility
|
0.84
|
| Interpersonal Sensitivity
|
0.86
|
| Obsessive-compulsive
|
0.86
|
| Paranoid Ideation
|
0.80
|
| Phobic Anxiety
|
0.82
|
| Psychoticism
|
0.77
|
| Somatization
|
0.86
|
Also, correlations between subscales averaged 0.67. The highest interscale correlation was between Obsessive-Compulsive and Depression (0.81) and the lowest was between Hostility and Phobia (0.48). (Ref: 4)
|
Alternate Forms:
|
No information found.
|
|
|
Validity Evidence
|
Construct/ Convergent/ Discriminant:
|
The author of the SCL-90 measured convergent validity by comparing it to the MMPI clinical scales, Wiggins content scales (W) and Tryon cluster scales (T). The highest correlations between SCL-90 scales and MMPI scales are as follows: (Ref: 2, see reference for table of all correlations)
| SCL-90 Scale
|
MMPI Scale
|
Coefficient*
|
| Somatization
|
Body Symptoms (T)
|
0.84
|
| Obsessive-compulsive
|
Schizophrenia
|
0.57
|
| Interpersonal Sensitivity
|
Poor Morale (W)
|
0.64
|
| Depression
|
Depression (W)
|
0.75
|
| Anxiety
|
Anxiety (T)
|
0.57
|
| Hostility
|
Resentment and Aggression (T)
|
0.68
|
| Phobic Anxiety
|
Phobias (W)
|
0.50
|
| Paranoid Ideation
|
Suspicion and Mistrust (T)
|
0.56
|
| Psychoticism
|
Schizophrenia
|
0.64
|
|
*p=0.01 for all
|
The SCL-90 correlates at 0.46 (p<0.05) with the Sandoz Clinical Assessment Geriatric (SCAG) scale. The affective subscale of the SCAG correlated at 0.65 (p<0.002) with the depression subscale, 0.64 (p<0.003) with the anxiety subscale, and 0.57 (p<0.04) with the total score. (Ref: 6)
|
Criterion-related/ Concurrent/ Predictive:
|
No information found.
|
Content:
|
No information found.
|
Responsiveness Evidence:
|
The Depression Factor of the SCL-90 had a sensitivity of 84.03% at a cut-score of 1.0, and sensitivity of 46.73% at a cut-score of 1.5. (Ref: 5)
|
Scale Application in VA Populations:
|
Yes. (Ref: 4)
|
Scale Application in non-VA Populations:
|
Yes. (Ref: 2-3,5-6)
|
|
|
Comments
|
This article has been abstracted by trained METRIC staff and is awaiting final review from a METRIC psychometrician for comments and recommendations. If you find that the above information contains any errors or if you have any questions about our abstraction, please use the form below to bring them to our attention.
|
Updates
No information found.
|
|
|
|
