SCD-48 - Registry of Scales and Measures

SENTENCE COMPLETION
TEST FOR DEPRESSION
LONG FORM
Version 3.1
SCD-48
Dr Stephen Barton
Division of Psychiatry and Behavioural Sciences
University of Leeds, UK.
(Copyright, 1999)
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SENTENCE COMPLETION TEST FOR DEPRESSION
Contents
Page
Introduction
1.1 What is SCD?
1.2 Examples of SCD Responses
1.3 SCD Helps Formulation
1.4 SCD Measures Depressive Thinking
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Guidelines for Valency Coding
2.1 Coding Guidelines
2.2 Reliability of Valency Coding
2.3 Using the SCD-48 Coding Form for Valency Coding
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5
6
6
Guidelines for Reference Coding
3.1 Models of Reference
3.2 Reference Objects
3.3 Agent Roles
3.4 Reliability of Reference Coding
3.5 Using the SCD-48 Coding Form for Reference Coding
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Coding Model
4.1 Responses of a Depressed Research Subject
4.2 Coding Model for the Depressed Research Subject
4.3 Summary of Reference Patterns
4.4 Coding Long Sentence Completions
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20
21
Appendix 1: Valency Coding Guide for SCD-48
Address for Correspondence
22
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SENTENCE COMPLETION TEST FOR DEPRESSION
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INTRODUCTION
1.1 What is SCD?
SCD is the Sentence Completion Test for Depression. It is a cognitive measure of
depressive thinking, designed to be used alongside global measures of depressive
symptomatology. Unlike most cognitive measures, it works like a projective test in
which people use their own words to finish incomplete sentences, giving an individual
picture of thought patterns. At the same time, the completed sentences can be classified
to provide valid and reliable measures of depressive thinking. Examples are given
below of sentence completions from a depressed patient (BDI = 32).
1.2 Examples of SCD Responses
Instructions: Use your own words to complete the sentences below. Try to express
how you have been feeling in the last week including today. Write the first thought that
comes to mind even if it doesn't seem an important one. You don't have to write more
than a few words for each one.
Stem
My friends
I did not
The future
Other people wonder
My mother
I could not
I trust
Our society
I think
The world
Completion
seem to cope with everything better than I do
like thinking over the past mistakes I've made
seems bleak
why I self-destruct all the time
has had a life of hell with me
trust another man again
my family as much as I could trust anyone
is not one I would have chosen to live in
I would like to learn to love myself
is a frightening place
1.3 SCD Helps Formulation
In addition to measuring depressive thinking, the content of the responses helps to
formulate the nature of the depression in individual cases. The above case demonstrates
a personal pattern of thinking suggesting guilt ("past mistakes") and relationship
problems ("I could not trust another man"). Also important is the presence of positive
thinking in spite of the depression ("I would like to learn to love myself").
1.4 SCD Measures Depressive Thinking
SCD is designed to elicit negative thinking specific to depression, not normal negative
thinking or negatives associated with other disorders. It has good construct validity and
cognitive specificity, demonstrated in empirical studies (e.g. Barton & Morley, in
press'). It was developed to test models of content-specificity, the types of cognitive
patterns present in particular emotional disorders, and the 48-item version can be used
to analyse depressive reference patterns. These are based on Beck's negative cognitive
triad (self, world and future) with two additional reference categories (others, past).
' Barton, S.B. & Morley, S.J. (in press). Specificity of Reference Patterns in Depressive Thinking:
Agency and Object Roles in Self-Representation. Journal of Abnormal Psychology.
SENTENCE COMPLETION TEST FOR DEPRESSION
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Using SCD-48, proportions of negative sentence completions falling within various
reference classes are the cognitive measures, and the following sections outline methods
for coding responses in this way. There are two main aspects of coding SCD responses:
valency and reference. Valency classifies completed sentences into negative, positive
or neutral types. Reference classifies the objects or topics that are depicted.
SENTENCE COMPLETION TEST FOR DEPRESSION
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GUIDELINES FOR VALENCY CODING
2.1 Coding Guidelines
These guidelines are used to classify completed sentences into one of three valency
types: negative, positive and neutral.
• Negative statements evoke situations in which any or all of the following are
present:
(a) distressing, painful or unpleasant emotion,
(b) unharmonious relationships with others or within the self,
(c) pessimism about plans or goals.
• Positive statements evoke situations in which any or all of the following are present:
(a) satisfaction, contentment or pleasurable emotion,
(b) harmonious relationships with others or within the self,
(c) optimism about plans or goals.
• Neutral statements contain either:
(a) factual information with no positive or negative content, or
(b) a combination of negative and positive content.
Other rules:
• Always classify the whole sentence, including the sentence-stem, not only the parts
the respondent has written.
•
Sometimes respondents complete a sentence, make a full stop, then begin a new
sentence. In these cases, only classify the first completed sentence.
•
Treat each completed sentence in isolation, as if it is the only sentence you have to
classify. Sometimes you may think respondents are referring back to previous
sentences, but for coding purposes only classify the content of the individual
sentence in question.
•
Classify the meaning expressed by the exact words that are used, not how you feel
about the scenarios that are depicted, or how you imagine the respondent may feel.
Only classify a sentence as negative or positive if it communicates affect or attitude
that fits the above criteria. If in doubt, code neutral.
•
Illegible or non-responses are classified separately and don't contribute to
measures of depressive thinking.
Appendix 1 (Page 22) lists each SCD-48 item with examples of negative, neutral and
positive sentence completions obtained from research with depressed and nondepressed people. In response to some of the items, neutral codes are uncommon so
examples are not given. This Appendix is used as an additional guide for valency
classification, particularly for responses that are difficult to code. Referring to
Appendix 1 (Page 22) maintains the reliability of valency coding, and coders are
strongly recommended to use it in conjunction with the above coding guidelines.
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SENTENCE COMPLETION TEST FOR DEPRESSION
2.2 Reliability of Valency Coding
Research using SCD-48 has found high inter-rater reliability of valency coding
(Intraclass correlation = 0.86; Barton & Morley, in press), and the test as a whole has
acceptably good internal consistency (Alpha = 0.79, established on the same data-set
reported by Barton & Morley, in press). A short form of SCD-48 (SCD-22) has been
developed by comparing the depressed sample reported in Barton & Morley (in press)
with a nondepressed community sample, retaining the items that discriminated best
between the two groups. Reports are currently in preparation. Preliminary analysis
suggests that cognitive specificity and inter-rater reliability of SCD-22 is comparable
with SCD-48. The internal consistency of SCD-22 is also improved (Alpha = 0.84).
There are, however, insufficient items to accurately measure reference patterns using
SCD-22, so it is anticipated it will be used mainly as a clinical rather than research
measure. 2
2.3 Using the SCD-48 Coding Form for Valency Coding
When valency judgements have been made, they can be recorded on the SCD-48
Coding Form, copies of which are enclosed with this manual. An extract is given in
Table 1. Simply, a tick is placed in the appropriate box to record the valency code for
any particular sentence completion. There is also a column for recording sentencestems where no response (or an illegible response) has been made. Valency codes can
be totalled and used to calculate the proportion of negative, or positive, statements made
by particular respondents, and these can be computed as a proportion of all responses,
or those falling within particular reference classes (e.g. self references).
Table 1. Extract from the SCD-48 Coding Form: Valency Coding
VALENCY
SCD ITEM
neg
newt
pos
-
p
+
REFERENCE
no
rasp
onse
agent
object
X
s o w f p
1. My friends
s
o
2. I did not
s
o s o w f p
3. Other people enjoy
s
o s o w f p
4. Our society
s
o s o w f p
5. Some people regret
s
o
s o w f p
6. I have
s
o
s o w f p
Z
Contact the author for copies of SCD-22, coding manual and forms.
SENTENCE COMPLETION TEST FOR DEPRESSION
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GUIDELINES FOR REFERENCE CODING
3.1 Models of Reference
Depressed people are purported to have negative thoughts directed at the self, the world
and the future (Beck, 1970) 3 . Barton & Morley (in press) extended these reference
domains to include other people and the past, hence, SCD-48 responses can be
classified into one of five reference object classes: self, other people, world, future and
past. Definitions are given below.
3.2 Reference Objects
The object of a reference is the main topic or theme that is depicted. In many sentences
there are descriptions of more than one object or topic, so the task is to decide on the
main reference object, what the sentence is mostly about.
• Self. The writer of the sentence is the main object, referring to him/her self by name,
by pronoun (e.g. "I", "me", "my"), to their state of being, thinking or feeling.
• Other People. Other people are the main object, described by name, by pronoun
(e.g. "he", "she", "they"), in terms of their states of being, thinking or feeling.
• World. Statements about the world, our society, the community, social situations, or
actions of people in the world are the main object. In relation to people's activity,
the emphasis is on the environment and external action rather than being or feeling.
• Future. A goal, plan or expectation of a future state or event is the main object.
• Past. A memory or past state or event is the main object.
Examples are given in Table 2 of a range of completed sentences classified in terms of
their main object. Some of these are very straightforward and are constrained by the
content of the sentence-stem (see Appendix 1, Page 22). Others refer to a number of
objects, and the main topic is open to judgement.
3.3Agent Roles
Some of the ambiguity concerning sentences with multiple references is resolved by
including a separate classification for the agent of a sentence. Agent roles are occupied
by individuals who think, feel or behave in relation to reference objects. For example,
in the following scenario, "My mother did not like me", the mother occupies the agent
role and the writer is the reference object. The roles are reversed in the following case:
"I did not like my mother". In this scenario, the writer has agency and the mother is the
object. Using SCD-48, there are two possible agency roles: self-as-agent, and othersas-agent. Examples are given in Table 2.
In some sentences there is no stated agent role (e.g. "The world is in a mess", "Last
week was just the same"), and in these cases it is implicit that the self, as writer, is the
Beck, A.T. (1970). The core problem in depression: The cognitive triad. In J.H.Masserman (Ed.),
Depression: Theories and Therapies. (pp. 47-55). New York: Grune & Stratton.
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SENTENCE COMPLETION TEST FOR DEPRESSION
agent. That is, self-as-agent is the default classification when agency is not explicit.
This type of statement is coded as if the writer had preceded the sentence with "I
believe" (e.g. "I believe the world is in a mess", "I believe last week was just the same":
see Table 2 for more examples).
Table 2. Examples of agent and object reference classification
Sentence Completions
ne cares only i r
Some people would not talk to others.
I did not want to go out today.
The world is in a mess.
Other people enjoy playing sport.
My father lives a ,few miles away.
Thefuture is what you make it.
Next week I am going to a party.
She fears what will happen next.
My friends are planning their future.
Iregret many things from the past.
Last week was just the same.
Some people regret their lives.
They think the past years have been bad.
Agent classification
Object classification
Other people
Self
Self (default)
Other people
Other people
Self (default)
Self (default)
Other people
Other people
Self
Self (default)
Other people
Other people
Other people
World
World
World
World
Future
Future
Future
Future
Past
Past
Past
Past
W&I&G,
3.4 Reliability of Reference Coding
Research using SCD-48 suggests that inter-rater reliability for reference coding is
acceptable (Barton & Morley, in press). The following intraclass correlations have
been observed between pairs of raters on their classification of object categories: Self =
0.89; Others = .78; World = .68; Future = .68; Past = .53. Inspection of the relevant
data revealed a restricted range of classifications in the Past category, with all other
correlations within conventionally acceptable limits. There was a very small number of
disagreements on agency roles confirming the discrimination between self and other as
agent in the sentence-stems.
3.5 Using the SCD-48 Coding Form for Reference Coding
When reference judgements have been made, they can be recorded on the SCD-48
Coding Form, as before. Simply, the relevant reference codes for agent and object are
circled and can be totalled later to investigate patterns of reference. (s = self, o = others,
w = world, f = future, p = past). Table 3 is an extract from the SCD-48 Coding Form,
giving examples of reference codes.
SENTENCE COMPLETION TEST FOR DEPRESSION
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Table 3. Extract from the SCD-48 Coding Form: Reference Coding
VALENCY
S C D ITEM
neg
neut
pos
_
p
+
no
rasp
onse
REFERENCE
agent
object
X
1. My friends
s
o
s o w f p
2. I did not
s
o s o w f p
3. Other people enjoy
s
o
s o w f p
4. Our society
s
o
s o w f p
5. Some people regret
s
o s o w f p
6. I have
s
o
s o w f p
SENTENCE COMPLETION TEST FOR DEPRESSION
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CODING MODEL
4.1 Responses of a Depressed Research Subject
To illustrate examples of combined valency and reference coding, the SCD-48
responses of a depressed research subject are given below in Table 4. This subject (BDI
= 39) was drawn randomly from the data-set reported in Barton & Morley (in press).
Using the above guidelines for valency and reference coding, and referring to Appendix
1 (Page 22), code these responses onto a blank SCD-48 Coding Form, then compare
them with the coding model in the following section (4.2). This is an important part of
learning how to code accurately, and is strongly recommended before using SCD-48
for either clinical or research purposes.
Table 4. SCD-48 responses of a depressed research subject
1. My friends Diane and Alison walk up to school.
2. I did not do anything wrong.
3. Other people enjoy going out at night.
4. Our society could be better.
5. Some people regret leaving the children.
6. I have two children.
7. The future is better than the past I hope.
8. She should not fuss over just one grandchild.
9. I care about my home and family.
10. Five years ago I thought I was happy.
11. I worry about where I am going to live.
12. Other people wonder how I cope by myself.
13. My mother worries about me.
14. Some people would not do what he did to me.
15. I trust nobody at the moment.
16. The world appears a cruel and hurtful place.
17. She fears that I will not be able to manage.
18. I feel scared and mixed up.
19. Last week I did the same as this week.
20. I could not go by myself.
21. They love the children, my two boys.
22. Next year will be better.
23. I hate him for doing this to me.
24. They think I should live nearer to them.
25. My family will help me.
26. I would not have done it if I had known.
27. He cares about me.
28. Things in general I can cope with.
29. I fear that I will not be able to manage.
30. Some people feel I am good at coping.
31. In five years time I hope to be safe and loved.
32. They did not tell me that it would be hard.
33. I love my children.
34. The past hurts me.
35. Other people hate what he did.