This case series aims to test the feasibility and acceptability of streamlined cognitive behavioral therapy (CBT) for adolescents with excessive worry. The treatment protocol focuses on reducing intolerance of uncertainty and the hypothesis is that this will help reduce worry.

This pilot study aims to test a new form of Cognitive Behavioral Therapy for adolescents with excessive worry. The investigators will include 12 participants with excessive worry and test the treatment which focuses on reducing intolerance of uncertainty (IU) in order to reduce worry.

Participants will be randomized to either one, two or three weeks of weekly baseline measurements prior to starting treatment, and will thus work as their on controls in this case series design.

Primary outcome measures will be collected at 12 weeks after treatment start. Participants will be followed up at three months after treatment.

Inclusion Criteria:

• A score on PSWQ-C of at least 22
• Age between 13 and 17 years
• Ability to read and write in Swedish
• A parent or caregiver that is able to co-participate in the treatment
• Participants on psychotropic medication must have been on a stable dose for the last 6 weeks prior to baseline assessment

Exclusion Criteria:

• Diagnosis of autism spectrum disorder, psychosis, bipolar disorder or severe eating disorder
• Present risk of suicide
• Ongoing substance dependence
• Occurrence of domestic violence
• Completed CBT for any anxiety disorder within the last 6 months (defined as at least 5 sessions of CBT including in vivo exposure sessions)