Pesky gNATs

In February 2014, together with Gary O’Reilly, I co-founded Handaxe CIC, a not-for-profit, community interest company dedicated to research and development of technology to support mental health interventions. This company is built on a spirit of generosity. We believe technologies that support mental health services can make an important contribution to society. But only if they are widely available. We aim to make our technologies available free of charge, or at the lowest possible cost to adolescent mental health services. Pesky gNATs was the first product developed by Handaxe Limited. It is a computer game and mobile app that implements core elements of Cognitive Behavioural Therapy and supports clinical interventions for young adolescents experiencing depression and anxiety. We also provide online training for mental health professionals who wish to use our software.

McCashin D, Coyle D, O’Reilly G (2020) A qualitative evaluation of Pesky gNATs in primary care – the experiences of assistant psychologists providing computer-assisted CBT to children experiencing low mood and anxiety. Internet Interventions. 2020, 100348, (doi)

O’Reilly G. Pesky gNATs! Using computer games and smartphone apps to teach complex cognitive behavioural therapy and mindfulness concepts to children with mental health difficulties. In: The Use of Technology in Teaching and Learning. Washington: Society for the Teaching of Psychology; 2018:231-247.

McCashin D, Coyle D, O’Reilly G. Children’s experiences with technology-assisted cognitive behavioural therapy: A Qualitative Synthesis. J Med Internet Res 2019;21(11):e13540. (doi

van der Meulen H, McCashin D, O’Reilly G, Coyle D. Using Computer Games to Support Mental Health Interventions: Naturalistic Deployment Study. JMIR Ment Health 2019;6(5):e12430. (doi)

Impact: the Pesky gNATs software is now in widespread use in youth mental health services in Ireland and the UK. This is largely due to the commitment of Gary O’Reilly in supporting training for therapists and helping to ensure the our research has an impact beyond academia. I am very grateful to Gary for his deep dedication.

Pesky gNATs website:

Further details of Pesky gNATs are available at the Pesky gNATs website. Therapists can also use this site to register and access the software.

Key collaborators:
Gary O’Reilly
Daragh McCashin
Ben Trewhella

The initial development of Pesky gNats was supported by the NHS Enterprise East through the SBRI Healthcare. It is also generously supported by University College Dublin and the University of Bristol. Development of the game would not have been possible without our long-term collaboration with the Ben Trewhella and Opposable Games.