LAUSR

79 they provide services for those with mental disorders. Such terminology is likely to be confusing to the potential consumer, given the varied meanings attached to the expression “mental wellness”. The considerable overlap in the age at onset of substance abuse and mental disorders in youth, and the resulting longterm association between the two, creates one more challenge. The new YMH services must be equipped to both assess and treat emerging as well as established substance abuse problems. While heavy use of alcohol and cannabis is transient among many young people, it may also be harbinger of later abuse and dependence. There is indeed an opportunity for effective prevention of substance abuse problems among heavy users through relatively brief, non-invasive, and effective interventions, some of which can be provided online. Including substance use services on an equal footing with those for mental disorders will require a more complex infrastructure, staffing, training and evaluation than what seems to be the case currently. Last, but not least, the epidemic of opioid abuse and the tragically high mortality associated with it remain largely absent from YMH service narratives, with some exceptions. Mental health services for these highly vulnerable youth will need to be connected to other interventions and systems of care currently in place for opioid abuse, so that youth can navigate between different aspects of care for these deadly problems. There is an implicit agreement that the new YMH services are designed for the age group of 12-25, based on the high incidence of mental health and addiction disorders during this period and the assumption that child psychiatric services are more adequately provided for the 0-12 year period. However, there is little empirical evidence to support the specific age range for which an entirely new system of care is being built, and issues of continuity with the age groups before and after should be addressed. Among those under 12 years of age, a substantial proportion present with developmental disorders, making them particularly vulnerable to future mental disorders. The new YMH services must be deeply connected with the system of care for developmental disorders and ensure the same unencumbered access for these youth as for those without prior developmental problems. At the other end of the age spectrum, most major disorders are likely to persist beyond 25 years of age and, therefore, need both episodic as well as continuous care of the highest quality. Shifting transition from 18 to 25 may postpone the problem, but not solve it. In summary, in setting up the new YMH system in multiple jurisdictions, some key issues need to be addressed, including connections with existing services, extending the transformation of service to the age period before and beyond 12-25 years, and providing equally weighted services to those with substance use disorders and pre-existing developmental disorders. The key principles underlying these services must guide an evaluation of a variety of methods of service delivery, as one model is unlikely to fit all circumstances and jurisdictions. Such evaluation will require innovative designs, as traditional randomized controlled studies will be difficult to conduct and we cannot hold back the progress that is already taking place. It would be prudent, even if not popular, to clearly define the boundaries of mental health and disorders to be able to serve those with the greatest needs. This will require research into different definitions of “caseness”, matched by provision of care appropriate to the stage and level of an existing or an emerging disorder. It is unlikely that YMH services can address all forms of distress in youth, the origin of and solution to some of which may be outside the field of health. This is likely to be particularly the case for the greatest proportion of youth on the planet who live in lowor middleincome countries, where poverty, political oppression, gross human rights violations, gender discrimination and violence, often resulting from post-colonial legacies, are major sources of distress. In the context of these environments, the current models of YMH services are not only unlikely to be workable but may be grossly inappropriate. Much of the globe will need to find its own solution to problems of youth, including mental and addiction disorders, using its own unique assets, but still able to incorporate the key principles generated from the current wave of YMH services discussed in this Forum.