Take it Personal!+: treatment for problematic substance use in people with mild intellectual disabilities.

Problematic substance use in people with mild intellectual disabilities is very common. This emphasises the importance of effective treatment, but treatment protocols appropriate for people with mild intellectual disabilities are scarce. In this PhD thesis, Take it Personal!+ was developed: a treatment for problematic substance use, adapted to the needs and limitations of people with mild intellectual disabilities. The effectiveness was investigated in an experimental study with multiple case studies. The results present the first indications of the effectiveness of Take it Personal!+ for reducing problematic substance use in people with mild intellectual disabilities. In addition, the qualitative study shows that clients and confidential advisors generally perceived the treatment as useful and helpful in changing substance use. The research also provides insight into how people with mild intellectual disabilities respond to motivational interviewing during Take it Personal!+. This led to relevant recommendations for practice to use interview techniques in a more targeted way. In doing so, this PhD thesis contributes to the improvement of the treatment of problematic substance use in people with mild intellectual disabilities.

Lotte Gosens completed her Master's in Clinical Psychology at Leiden University. During her Master’s research and clinical internship, her passion for clinical research and the role of scientist-practitioner emerged. Her passion for working with people with mild intellectual disabilities also originated here. At the same time, she realised that more clinical research is needed in this target group. After completing her Master’s, she embarked on her career as a scientist-practitioner at Pluryn. She combined her PhD research with her work as a psychologist. This PhD thesis describes the research she conducted during these years. She received the '2022 International Research Award of the Journal of Intellectual and Developmental Disability'. In 2023, she started the post-master Mental Health psychology study programme at Radboud University in Nijmegen.