How Does Behavioural Activation Work? A Systematic Review of the Evidence on Potential Mediators.

INTRODUCTION: Behavioural activation is an effective treatment for depression, but little is known about its working mechanisms. Theoretically, its effect is thought to rely on an interplay between activation and environmental reward. OBJECTIVE: The present systematic review examines the mediators of behavioural activation for depression. METHODS: A systematic literature search without time restrictions in Medline, EMBASE, PsycINFO, The Cochrane Library, and CINAHL resulted in 14 relevant controlled and uncontrolled prospective treatment studies that also performed formal mediation analyses to investigate their working mechanisms. After categorising the mediators investigated, we systematically compared the studies' methodological quality and performed a narrative synthesis of the findings. RESULTS: Most studies focused on activation or environmental reward, with 21 different mediators being investigated using questionnaires that focused on psychological processes or beliefs. The evidence for both activation and environmental reward as mediators was weak. CONCLUSIONS: Non-significant results, poor methodological quality of some of the studies, and differences in questionnaires employed precluded any firm conclusions as to the significance of any of the mediators. Future research should exploit knowledge from fundamental research, such as reward motivation from neurobiology. Furthermore, the use of experience sampling methods and idiographic analyses in bigger samples is recommended to investigate potential causal pathways in individual patients.

Thoracic aortic vascular graft infection: outcome after conservative treatment without graft removal.

OBJECTIVES: Surgical debridement with aortic graft removal is considered the preferred treatment for thoracic aortic vascular graft infection (VGI). Conservative treatment with antibiotics only is usually reserved for inoperable patients. Due to Outpatient Parenteral Antimicrobial Therapy (OPAT) and better understanding of the antibiotic impact on biofilms, long-term targeted antibiotic therapy without graft removal may be an alternative treatment option for selected thoracic aortic VGI patients. The aim of this case series was to evaluate the outcome in patients with thoracic aortic VGI who were treated without graft removal. METHODS: This single-centre retrospective cohort study evaluated patients with a thoracic aortic VGI diagnosed between 2008 and 2021 and who were treated without graft removal. The primary outcome parameter was the 6-month mortality rate after VGI diagnosis. Secondary outcome parameters were cure rates and relapse of infection. RESULTS: Twenty-four patients with thoracic aortic VGI who were managed without graft removal were identified. The mortality rate 6 months after VGI diagnosis was 8% (2/24); one of these deaths was infection related. The median antibiotic treatment duration was 13 months (interquartile range 15). A total of 16 patients (67%) were cured. No relapses occurred after a median of 24-month (interquartile range 32) follow-up. CONCLUSIONS: Intensive antibiotic treatment, without graft removal, may be a non-inferior option in patients with a thoracic aortic VGI who are not considered for surgery.