PRINCE primary is cluster randomised waiting list controlled trial to evaluate the feasibility of an integrated approach to care in general practice for adults with persistent physical symptoms (PPS). PPS is defined as physical symptoms with no obvious underlying organic. 240 patients with PPS recruited from 8-12 GP practices in London will be randomised to the integrated care approach plus treatment as usual (TAU) or TAU alone. The integrated GP approach consists of providing GPs with a short cognitive behaviour therapy (CBT) skills training, ongoing supervision, as well as written and audio-visual materials/guidelines. In addition, participants randomised to the intervention group will receive tailored CBT-based self-help materials (i.e. written and audio-visual materials).

Patients with PPS are often severely functionally impaired and. They consume large amounts of healthcare and welfare benefits. There is an accumulating body of evidence showing that cognitive behavioural interventions can reduce levels of symptoms and improve overall functioning in patients with PPS. CBT has demonstrated both short-term and long-term efficacy with small to medium effect sizes for PPS. Larger treatment effects have been reported for specific PPS syndromes, including non-cardiac chest pain, Irritable Bowel Syndrome (IBS), and Chronic Fatigue Syndrome (CFS).

General practitioners (GPs) play a major role in identifying and managing patients with PPS. A previous randomised parallel group pilot trial investigated the feasibility (i.e. recruitment, retention and acceptability) of implementing a primary care Symptoms Clinic for patients with PPS). The Symptoms Clinic comprised a structured set of consultations delivered by a specially trained GP with a strong interest in PPS. The intervention included exploring potential biological mechanisms underlying the PPS condition, empathetic support, and training patients in symptom-management (i.e. medication or cognitive behavioural techniques). The results indicated that the Symptoms Clinic was acceptable to the majority of patients randomised to the intervention group, and may have the potential to generate clinically significant benefits. However, this pilot study did not assess feasibility parameters referring to GPs' willingness to participate in the study and undergo specialised psychological training. Moreover, the intervention was carried out by only one GP, raising questions about the generalizability of the study.

Managing patients with PPS can be highly challenging in general practice. Although GPs recognise the treatment of PPS as a responsibility of primary care, previous studies show that GPs often feel powerless, frustrated and helpless when encountering these patients. Furthermore, GPs frequently report that factors such as time constraints and the lack of psychological training prevents them from effectively addressing patients' psychosocial needs and developing appropriate doctor-patient communication skills.

The aim of this study is to assess whether it is feasible to conduct an adequately powered future trial to evaluate the efficacy and cost-effectiveness of a CBT-based integrated GP care approach for treating patients with PPS (please refer to arms and interventions for more details).

Patients that fit the eligibility criteria will be invited to take part in the study. Patients will be considered eligible for inclusion in this study if they fulfil all of the following criteria:

(i) have a PPS diagnosis (which are medically unexplained) (ii) are greater than or equal to 18 and less than or equal to 65 years old (iii) are registered with a GP practice in South London that has consented to taking part in PRINCE Primary (iv) have had 6 or more consultations in the last year (not necessarily for the same symptom or directly related to PPS (v) have given written informed consent, provided baseline data before randomisation and can speak and read English at a level adequate for participation in the.

Patients will be excluded from the study if the patient has:

(i) active psychosis (ii) drug or alcohol addiction as indicated in the patient's medical notes (iii) current benzodiazepine use exceeding the equivalent of 10mg diazepam per day (iv) had any psychotherapy treatment within the last year (not inclusive of general visits from community psychiatric teams) (v) dissociative seizures (vi) if they are at imminent risk of self-harm, after psychiatric/ psychological assessment (vii) taking part in the PRINCE Secondary study or the ACTIB Study (Everitt et al., 2015).

Patients and GPs will not be blind to treatment allocation due to the nature of the trial (i.e. therapy trial). The trial team member responsible for treatment allocation will be unblind. All outcome data are based on self-report and will be collected either by post or email. The research assistant(s) responsible for contacting participants who have not returned or completed follow-up questionnaires will be unblind. Moreover, the Data Monitoring and Ethics Committee (DMEC), research workers and trial statisticians will remain blind to treatment allocation.