Exploring the Prevalence and Predictors of Deterioration After Low Intensity Cognitive Behavioural Therapy

This research investigates clinical deterioration in adults following low-intensity cognitive behavioural therapy (LICBT), a brief psychological intervention for mild to moderate common mental health problems. LICBT is widely implemented in primary care mental health services in England. While its effectiveness is well-documented, its potential for negative outcomes (e.g., a worsening of mental health symptoms) remains underexplored.

The first chapter of this thesis presents a systematic review examining deterioration rates and risk factors for deterioration after LICBT. Forty-four studies were initially included, with only seven reporting deterioration rates (15.9%). The vast majority of studies were internet-based interventions targeting depression and anxiety in European community settings. Deterioration rates ranged from 0% to 6% using a wide variety of clinical outcome measures and statistical methods to calculate deterioration rates. No studies conducted subgroup analyses to identify potential risk factors for deterioration.

The second chapter details an empirical study using data from patients who accessed LICBT in NHS Talking Therapies Services in England. Statistical methods were used to identify two types of deterioration: those likely to be caused by the treatment itself (iatrogenic harm) and those related to natural illness progression. The estimated deterioration rates were around 16% of patients who accessed LICBT (11% iatrogenic and 5% chronic). Common characteristics identified in participants experiencing deterioration include having more than one co-occurring mental health problem, severe impairment to daily activities, unemployment, and living in socioeconomically deprived neighbourhoods.

Although further research is needed, these findings suggests that deterioration in LICBT may be more common than previously thought.