Background: Cognitive behavioural therapy (CBT) has, in the space of 50 years, evolved into the dominant modality in psychological therapy. Mechanism/s of change remain unclear, however.Aims: In this paper, we will describe key features of CBT that account for the pace of past and future developments, with a view to identifying candidates for mechanism of change. We also highlight the distinction between ‘common elements’ and ‘mechanisms of change’ in psychological treatment.Method: The history of how behaviour therapy and cognitive therapy developed are considered, culminating in the wide range of strategies which now fall under the heading of cognitive behavioural therapy (CBT). We consider how the empirical grounding of CBT has led to the massive proliferation of effective treatment strategies. We then consider the relationship between ‘common factors’ and ‘mechanisms of change’, and propose that a particular type of psychological flexibility is the mechanism of change not only in CBT but also effective psychological therapies in general.Conclusion: Good psychological therapies should ultimately involve supporting people experiencing psychological difficulties to understand where and how they have become ‘stuck’ in terms of factors involved in maintaining distress and impairment. A shared understanding is then evaluated and tested with the intention of empowering and enabling them to respond more flexibly and thereby reclaim their life.

Fatigue is widespread in the population, particularly among working people. Exhaustion disorder (ED), a clinical manifestation of burnout, is common, but, after treatment, about one-third still experience fatigue and other physical symptoms. We propose that in some instances, fatigue as a persistent physical symptom (PPS) might be a more appropriate formulation of ED patients’ fatigue problems, and we suggest that ED patients who meet fatigue PPS criteria will differ from other ED patients in terms of psychological distress, non-fatigue PPSs and functional impairment. Questionnaires were sent to 10,956 members of a trade union of which 2479 (22.6%) responded. Of 1090 participants who met criteria for ED, 106 (9.7%) met criteria for fatigue as a PPS. Participants who met fatigue PPS criteria scored on average higher on measures of depression, anxiety and functional impairment and were more likely to have clinically significant scores. Moreover, they had 27 times higher odds of meeting other PPS subtypes and reported more non-fatigue PPS subtypes, suggesting a more complex health problem. Specific evidence-based interventions are available for both ED and PPSs, and therefore, it is crucial to accurately formulate the fatigue problem reported by patients to provide appropriate treatment.

Non-Cardiac Chest Pain (NCCP) is persistent chest pain in the absence of identifiable cardiac pathology. Some NCCP cases meet criteria for Persistent Physical Symptoms (PPS), where the symptoms are both persistent and distressing/disabling. This study aimed to identify patients that might need specialist treatment for PPS by examining cases of NCCP that meet PPS criteria. We analysed data from 285 chest pain patients that had received an NCCP diagnosis after attending an emergency cardiac department. We compared NCCP patients who did and did not meet the additional criteria for heart-related PPS and hypothesised that the groups would differ in terms of psychological variables and workability. We determined that NCCP patients who meet PPS criteria were more likely than other NCCP patients to be inactive or unable to work, reported more general anxiety and anxiety about their health, were more depressed, ruminated more, and, importantly, had a higher number of other PPS. A high proportion of NCCP patients meet PPS criteria, and they are similar to other PPS patients in terms of comorbidity and disability. This highlights the importance of focusing psychological interventions for this subgroup on the interplay between the range of physical and psychological symptoms present.

In this study the illicit drug use of 62 prison inmates who claimed to have made a “false confession” during police interrogation sometime in their lives was compared with those of other inmates. The results showed that the “false confessors” were significantly more frequent users of illicit drugs than the other inmates and had more serious drug abuse problems, including intravenous drug use. Twenty-five per cent of the false confessors and 10% of the other inmates were heavily dependent on drugs. The difference was highly significant. The drug-dependent false confessors were particularly likely to have confessed falsely to protect someone else from being arrested and prosecuted.