Abstract:
The transdiagnostic approach to anxiety treatment focuses on processes shared across
diagnostic categories. Negative affectivity (NA) may represent an area of core pathology
joining the anxiety disorders, mood disorders and the schizophrenia spectrum. Treatments
aimed at improving NA‐related factors amongst diagnostically heterogenous groups appear to
be almost as effective as diagnosis‐specific treatments. This thesis presents the results of an
idiographic, multiple‐baseline evaluation of Engage, which applied the transdiagnostic
approach to a group education and support setting for people with heterogenous anxiety and
mental disorder. 100% of participants said they found the programme useful, 62.50% of the
participants showed improved anxiety severity post‐intervention and at follow‐up and 62.50%
of participants showed improved mental‐disorder severity post‐intervention. However, at
follow‐up only 33.33% of participants showed an improvement in mental‐disorder severity.
Transdiagnostic support programmes may be beneficial to people with a variety of anxiety
problems and a range of diagnoses, though not as much as full transdiagnostic treatment
protocols. While anxiety improvements were maintained over time, the transdiagnostic effects
on untargeted mental disorder were not maintained for those participants who were
medicated throughout the programme. These findings are discussed in light of other research
pertaining to effective treatments and support programmes and the impact of medication
upon treatment generalisation. Conclusion: The transdiagnostic approach may have utility for
the schizophrenia spectrum. Transdiagnostic education and support may be a useful adjunct
or pre‐cursor to treatment. Medication may interfere with transdiagnostic intervention effects.
