Western Victoria Primary Health Network (PHN) CEO Jason Trethowan is leaving the organisation to take up the top job at youth mental health initiative Headspace.

Mr Trethowan, who was also CEO of the PHN's predecessors the General Practitioners Association of Geelong and Barwon Medicare Local, has long been a champion for the use of eHealth in primary care, having been heavily involved in one of the Wave 2 sites for the implementation of the PCEHR.