Appendix.

The Intolerance of Uncertainty Scale for Children (IUSC), Parent- and Child-report Forms

Item	Parent-report form	Child-report form
1	Uncertainty stops my child from having strong opinions	Doubts stop me from having strong opinions
2	My child believes that being uncertain means one is mixed-up	Being unsure means that a person is mixed-up
3	Uncertainty makes my child’s life intolerable	Not knowing what will happen in the future makes life hard
4	My child thinks it’s unfair that we can’t predict the future	It’s not fair that we can’t predict the future
5	My child’s mind can’t be relaxed if he/she doesn’t know what will happen tomorrow	I can’t relax if I don’t know what will happen tomorrow
6	Uncertainty makes my child uneasy, anxious, or stressed	Not knowing what will happen in the future makes me uneasy, anxious, or stressed
7	Unforeseen events upset my child greatly	Surprise events upset me greatly
8	It frustrates my child to not have all the information he/she needs in a situation	It frustrates me to not have all of the information I need
9	Uncertainty keeps my child from living a full life	Not knowing what could happen keeps me from enjoying life
10	My child believes that one should always look ahead so as to avoid surprises	One should always think ahead to avoid surprises
11	My child believes that a small unforeseen event can spoil everything, even with the best planning	Plans can be ruined by things you didn’t think would happen.
12	When it’s time to act, uncertainty paralyzes my child	When it is time to do things, not knowing what could happen keeps me from acting
13	My child believes that being uncertain means that he/she is not first rate	Being unsure of things means that I am not great
14	When my child is uncertain he/she can’t go forward	When I am not sure of something I can’t go forward
15	When my child is uncertain he/she can’t function very well	When I am not sure of something I can’t work very well
16	Other children seem to be more certain than my child	Other kids have less doubts than I do
17	Uncertainty makes my child unhappy or sad	Not knowing what will happen makes me unhappy or sad
18	My child always wants to know what the future has in store for him/her	I always want to know what will happen to me in the future
19	My child can’t stand being taken by surprise	I don’t like being taken by surprise
20	The smallest doubt can stop my child from acting	The smallest doubt can stop me from doing things
21	My child feels as though he/she should be able to organize everything in advance	I should be able to prepare for everything in advance
22	My child feels as though being uncertain means that he/she lacks confidence	Being unclear about things means that I am not confident
23	My child feels as though it’s unfair that other people seem to be sure about their future	It’s not fair that other kids are more sure of things
24	Uncertainty keeps my child from sleeping soundly	Not knowing what can happen keeps me from sleeping well
25	My child tries to get away from all uncertain situations	I must get away from all situations where I don’t know what will happen
26	The ambiguities of life stress my child	Things that are unclear stress me
27	My child can’t stand being undecided about the future.	I don’t like being undecided about the future.

Note. Respondents rate the extent to which they agree with each item along a 5-pt scale (1=not at all, 3=somewhat, and 5=very much).