The purpose of this study is to determine whether a specific component of Acceptance and Commitment Therapy (ACT) called 'Self as Context' is an important and necessary part of this therapeutic approach.

Inclusion Criteria:

• Adults of working age (18-65)
• Patients with a primary positive diagnosis of a long-term health condition (The most common conditions referred to the service are Diabetes, Chronic Obstructive Pulmonary Disease [COPD], Rheumatoid Arthritis and Epilepsy) where there is a verifiable medical diagnosis supported by the patients General Practitioner (GP) and/or secondary care physician
• Patients with concurrent mental health difficulties (defined as mild - moderate anxiety and/or depression, see table one).

Exclusion Criteria:

• Patients with a primary diagnosis of 'medically unexplained symptoms' (MUS) including somatoform disorders (e.g. pain disorder, conversion disorder, body dysmorphic disorder, hypochondriasis) and functional somatic syndromes (e.g. irritable bowel syndrome, chronic fatigue syndrome, fibromyalgia, non-cardiac chest pain, non-epileptic seizures)
• Mental health diagnoses in addition to mild - moderate anxiety / depression (e.g. personality disorder, bipolar disorder, psychosis etc.)
• Patients in receipt of secondary care mental health services
• Patients with severe and enduring mental health difficulties
• Significant risk issues, or current substance misuse
• Previous contact with mental health services (defined as two or more prior episodes of contact without significant change)
• Inpatient admission for mental health difficulties within the last five years
• History of overdoses or other self-injury
• Stated reluctance to engage in psychotherapy