In 2012 he completed year-long Post Doctoral training at the Center for Cognitive Therapy, at the University of Pennsylvania's Perelman School of Medicine with a focus on advanced skills in cognitive behavioral therapy.

Nikolaos holds Bachelors with Hons (First Class) and Masters of Arts in Psychology (Awarded with Distinction), and a Postgraduate Diploma in Clinical Psychology. His PhD research centered on developing strategies to enhance engagement in cognitive behavioural therapy and was conferred in 2001.

Following practice in New Zealand through 2008 he was registered with the Australian Psychologist's Board in 2009 with an approved area of practice endorsement in clinical psychology. He was appointed to the grade of Fellow of the Australian Psychological Society in 2016.