An infographic has been produced by Companions of London on the likely / intended benefits of Cognitive Stimulation Therapy (CST) as a treatment for persons with dementia:
Understanding Cognitive Stimulation Therapy: CST and Dementia (Infographic). London [Online]: Companions of London, January 16th 2018.
This appears to relate to:
Aguirre, E. Spector, A. [and] Hoe, J. [et al] (2010). Maintenance Cognitive Stimulation Therapy (CST) for dementia: a single-blind, multi-centre, randomized controlled trial of Maintenance CST vs. CST for dementia. Trials. April 28th 2010; 11: 46.
Note: There is no shortage of more recent and balanced assessments of the evidence for CST available, published subsequently by members of the same team.
For example, a recent article, this time relating to individual CST, is more ambivalent:
Orrell, M..Yates, L. [and] Leung, P. [et al] (2017). The impact of individual Cognitive Stimulation Therapy (iCST) on cognition, quality of life, caregiver health, and family relationships in dementia: a randomised controlled trial. PLoS Medicine. March 28th 2017; 14(3): e1002269.