More needs to be done during early childhood, write Peter Gluckman and Harlene Hayne.
All too frequently do we read news of yet another tragic end to a young life in New Zealand - from suicide, vehicle accident or binge drinking. International statistics show that young people in New Zealand do poorly on many measures relative to those in other developed countries.
While most of our young people cope well with the transition to adulthood, the passage through adolescence for at least 20 per cent of young New Zealanders will have long-term consequences.
Last week the chief science adviser's office released a report entitled "Improving the transition: reducing social and psychological morbidity during adolescence". The report was commissioned by the Prime Minister because of the continuing public concern about adolescents and young people.
This is not a typical report; it is not about making specific recommendations. Rather, for the first time it provides a comprehensive summary of what we know from a scientific perspective about adolescence.
It is logical to base policy development in complex areas like adolescence on an unbiased assessment of the evidence.
There are two overarching themes in the report. The first is that application of the international and domestic evidence in this area should lead to better outcomes for New Zealand adolescents. In the past, some new programmes in child and youth development have been introduced with good intent but are unlikely to succeed because they are not supported by the evidence.
Similarly, other approaches that the evidence suggests are more likely to be effective have not been implemented.
The second overarching theme of the report is that social investment in New Zealand should take more account of the growing evidence that prevention and intervention strategies applied early in life are more effective and reap more economic returns than do strategies applied later. This will require long-term commitment to appropriate policies and programmes.
The report points out that adolescence is now a prolonged period, as the age of puberty has fallen and the age at which young people are accepted as adults has risen. Brain maturation is not complete until well into the third decade of life, and the last functions to mature are those of impulse control and judgment. Yet it may surprise many readers to learn that early childhood is the critical period in which the fundamentals of self-control are established. Children who do not adequately develop these abilities in early life are more likely to make poor decisions during adolescence, given the inevitable exposures to risk in the teenage years.
More can be done to improve self-control by reorientation of early childhood programmes. Further, the evidence is compelling that targeting intensive but costly interventions towards the higher-risk sections of the community has a high rate of social and economic return. Therefore, in evaluating early childhood programmes, it is important that we understand what their purpose is and whether they are delivering.
We present evidence that the adolescent brain is more sensitive to both alcohol and cannabis, with long-lasting adverse consequences for far too many. Educational programmes appear less effective than measures that restrict access.
In addition, a significant proportion of young people suffer from depression and other mental health disorders, yet the range and capacity of services available to them is inadequate. Given New Zealand's high rate of adolescent suicide and psychological morbidity, it seems that greater priority should be given to addressing this capacity gap and to raising public awareness of the particularities of adolescent depression.
While the issues and their solutions are generic across all of our population, programmes must be developed and delivered in culturally appropriate ways to the very different communities that now make up a greater proportion of young New Zealand.
Targeted investments in the "long tail" of educational underachievement and social disengagement will be needed. The problems of adolescence are disproportionately found within sectors where there is intergenerational disadvantage.
The report does not pretend there is any magic bullet - there isn't one. Rather, it points out that a holistic approach that takes into account investment in the earlier phase of development is likely to pay real dividends for our young people over a decade or so.
There will always be a tension between targeted interventions and universalism and the data points to the benefits of both approaches - the policy issues of targeted interventions are complex but there can be no doubt that for young people in situations of disadvantage from early life, different levels of intervention can be shown to have long-term benefit and to be highly cost-effective.
Sir Peter Gluckman is chief science adviser to the Prime Minister. Professor Harlene Hayne is deputy vice-chancellor and professor of psychology at the University of Otago, and co-chaired the taskforce.