# Cognitive Behavioural Therapy and Dual Diagnosis: A Systematic Review Exploring Its Effectiveness and Implications for Nursing Practice

## TL;DR

This paper reviews the effectiveness of Cognitive Behavioural Therapy for treating dual diagnosis, which involves both mental health and substance use disorders.

## Contribution

The study systematically evaluates CBT's role in treating dual diagnosis, highlighting its potential and challenges in nursing practice.

## Key findings

- CBT-based interventions showed some improvement in mental health or substance use symptoms.
- Mental health nurses are well-suited to deliver CBT-based interventions for dual diagnosis.
- Additional support structures are needed for nurses to effectively deliver CBT.

## Abstract

Dual diagnosis (DD) is defined as the presence of a co‐occurring mental health and substance use disorder. It is associated with poor treatment outcomes, which can be further fuelled by frequent exclusion from specialist treatment due to the separation between mental health and drug and alcohol services. Cognitive Behavioural Therapy (CBT) has an extensive evidence base in treating mental health and substance use disorders in isolation, but there is a paucity of evidence regarding its efficacy in treating DD. The current systematic review aimed to explore the use and effectiveness of CBT as a treatment for individuals with DD. Sources were derived in September 2024 from electronic databases including Medline, PsychINFO, Embase and CINAHL; topically relevant meta‐analyses were also citation tracked. Twenty‐three studies were included in this review from a total of 2364 which were initially retrieved. Study outcomes highlighted that CBT‐based interventions provided some level of improvement to mental health or substance use symptoms, although several interventions did not display superiority when compared to typical addiction approaches. Mental health nurses are well suited to deliver CBT‐based interventions and could address the current treatment gap experienced by individuals with DD. This could include supporting patients in maintaining and generalising CBT skills that have already been acquired, which would help guarantee accessibility to CBT‐based interventions over a longer time period. However, additional support structures would need to be implemented to allow nurses to deliver CBT effectively, such as access to training, supervision, protected time and reflective practice.