Johan graduated from the University of Groningen in 1976 and after 5 years of working as a treatment coordinator in the TBS, switched to a position as a clinical psychologist in the general hospital in Almelo. There he was head of the department of Clinical Psychology for several years. In 2005 he founded Brain Dynamics Hengelo B.V.. This practice was taken over by the neuroCare Group Netherlands B.V. in November 2017.
Johan has specialized in the treatment of complex neuropsychological disorders such as ADHD, chronic depression and personality disorders. He mainly focuses on the application of neuromodulation techniques such as neurofeedback and rTMS.