The goal of this feasibility and acceptability trial is to test whether a new brief talking therapy can be successfully provided to and is suitable for adolescents (16-18) who are seeking help from Child and Adolescent Mental Health Services (CAMHS).

The main research question for the current study is: Is it feasible and acceptable to offer a brief values-based (helping young people identify what matters most to them) and imagery (using imagination to visualise positive experiences) intervention for adolescents experiencing paranoia in CAMHS?

It also aims to identify preliminary clinical outcomes, particularly changes in paranoia severity as measured by the Revised Green et al., Paranoid Thoughts Scale (R-GPTS).

Participants will complete an eligibility assessment and those eligible will be offered a six-session intervention. Assessment measures will be completed before, during and after the intervention.

Paranoia involves intense fears that others intend to cause harm. This fear of being under threat and unable to trust others often causes a young person significant distress and impairs everyday functioning. Paranoia is common in adolescence (20-30% report weekly fears, rising to 35% among those seeking mental health care), occurring not only in psychosis but across a range of mental health disorders. Help-seeking adolescents with various non-psychotic conditions commonly report paranoid thoughts. Despite the prevalence and impact, there are currently no proven therapies designed specifically for young people experiencing paranoia. This trial aims to address this gap.

Current treatments for paranoia focus almost exclusively on adults. In adult populations, values-based approaches and mental imagery techniques have shown promise in reducing paranoia. These interventions address underlying cognitive processes, negative beliefs about self and others, distressing mental images, and lack of values-directed behaviour, which maintain paranoid thinking. However, youth mental health interventions require developmentally appropriate approaches.

This study's primary aim is to evaluate the feasibility and acceptability of delivering a brief psychological intervention to adolescents experiencing paranoia. Feasibility will assess whether the intervention can be practically delivered within a CAMHS setting, including recruitment capability, participant retention, and completion of study procedures. Acceptability will examine whether young people find the intervention suitable.

Secondary aims include exploring preliminary clinical outcomes. We will examine changes in paranoia symptoms, self and other beliefs, mental imagery, valued action and day-to-day functioning.

This study employs a single-case experimental design (SCED) with multiple baseline lengths (2, 3 and 4 weeks).

After screening for eligibility and completing pre-intervention questionnaires, participants begin a randomly assigned baseline phase to establish stable symptom measurement. Participants then receive six weekly one-hour individual therapy sessions. Outcome measures are completed throughout the intervention to track changes.

One month post-intervention, participants complete a follow-up assessment with the same outcome measures to evaluate maintenance of treatment effects and provide further feedback on their experience.

This feasibility trial addresses a critical treatment gap for adolescent paranoia. If successful, findings could guide the development of larger definitive trials. Positive findings could contribute to the development of evidence-based interventions for young people experiencing paranoia in routine mental health services.

Inclusion Criteria:

• Aged 16-18
• Seeking help from a Child and Adolescent Mental Health Service (CAMHS)
• A score ≥ 11 on the R-GPTS (Scale B)
• Sufficient understanding of English
• Capacity to consent, as assessed during the initial interview
• Wanting support with paranoia
• Low- moderate mental health risks (emotional difficulties that impact functioning, but no immediate risk to safety e.g., no suicidal intent).

Exclusion Criteria:

• Severe comorbid diagnoses apparent at the initial assessment (e.g., a primary alcohol or substance dependence issue measured using standardised assessments)
• The presence of a developmental disability or cognitive impairment that would interfere with participation.
• Concurrent participation in another psychological therapy
• High levels of current risk (e.g., significant and immediate concerns about the young person's safety, such as suicidal intent).

We request optional consent to share fully anonymised data with other researchers to support future studies. If consent is not given, or if confidentiality cannot be fully protected, individual participant data will not be shared.