Table 1

Example scenarios for worry-related and rumination-related CBM-I and active control conditions

	Scenario type	Scenario	Benign ending*	Negative ending†	Question	Benign/correct answer
Worry	Social relationships	You haven’t socialised much with the other members of your fitness class but following a good workout, you all go out for lunch. Later, when you are walking out of the restaurant, you overhear two members of the class talking about you. As you listen, you hear them saying that they think you are…	Alright	Boring	Do the other team members dislike you?	No
	Performance	You are learning how to use a new piece of software and have been completing tutorials online. The test is coming up in a few days and thinking about the amount of effort you have put in, you know you will do…	Very well	Badly	Will you fail the test?	No
	Illness and harm	You are walking down the road to your house late at night when you fall over and scrape your knee. When you look up, a group of teenagers are walking towards you. One of them reaches into their pocket and pulls out a…	Tissue	Knife	Did the teenagers help you?	Yes
	Test‡	Your flatmate is working late so you are in the house on your own this evening. You have just switched off the lights and got into bed when you hear a scraping in the lock of the front door. As you slowly approach the front door, it opens and you see what was causing the noise.	–	–	Is your flatmate home from work?	Yes
Rumination	Social relationships	At the bus stop, you bump into someone from your school days. They comment on how much you have changed since they last saw you. Mulling it over later, you think about their tone of voice and decide that they meant their comment to be…	Complimentary	Hurtful	Did the person intend to be mean?	No
	Abilities	You overhear someone at work saying that the company is making a few people redundant. You start thinking about the contribution you have made to the team since you started working at the company, and as you think it over, you suspect that you will be…	Safe	Made redundant	Will you be sacked?	No
	Feeling low	You are feeling quite exhausted. On social media, you see a photo of you when you felt better. As you think back to that time, you wonder whether in the future there will be times when you will feel less exhausted and you can see that there is…	Hope	Little prospect	Will you always be tired?	No
	Test	Your work contract is coming to an end. A colleague offers to organise leaving drinks for you and they email round the office to ask who is free. As you think back over your relationships with your colleagues, you can guess how many people are likely to come along.	–	–	Will a lot of people come along to your leaving do?	Yes
Control§	Ambiguous	You went on holiday with two friends. Your friends planned to go to a particular place, but you'd been there before and so a new destination was found. Looking back, you wonder whether your friends minded changing the plans for you.	–	–	Did your friends resent having to change the plans?	No
Control§	Fact	Your mother lends you her brand new suitcase to take on a plane journey. You try to look after it but when you arrive at your destination, you see the case is damaged. As you contemplate telling your mother, you know who she will blame for the damage.	–	–	Did you take the suitcase on the train?	No

*In 76% of trials, the scenarios are provided with a benign ending.
†In 12% of trials, the scenarios are provided with a negative ending.
‡Test trials remain ambiguous and make up the final 12% of trials. Participants’ response to the test trial question indicates the interpretation they have made.
§While all CONTROL scenarios remain ambiguous, 50% are followed by questions that assess participants’ interpretation of the scenario (including disorder-specific test trials as above) and 50% relate to other fact-based information in the scenario that is not ambiguous and is emotionally neutral.