Inoue & Fujita made the point that clarifying the criteria of NSSI in DSM-5 facilitated discussion on the topic of suicide prevention. The problem of rising suicide rates among the younger population of Japan was also highlighted. Suicide has been identified as a leading cause of death in young Japanese people, with a significant societal impact. ^{Reference Yip1} We would agree on the importance of fostering discussion and understanding of suicide at national and international levels. We would also agree that addressing suicide prevention among younger age groups is a public health priority for many countries.

Internationally, suicide rates in younger people have increased over the past 50 years. ^{Reference Patton, Coffey, Sawyer, Viner, Haller and Bose2} This phenomenon is apparent in Ireland where we now have the fourth highest youth suicide rate (under 25 years) in the expanded European Union. ^{Reference Malone3} In May 2013 the Suicide in Ireland survey was published, a national research study exploring Irish suicide statistics, with a focus on young lives lost to suicide. ^{Reference Malone3} This study identified a fourfold rate of increased suicide risk in males between the ages of 16 and 20, compared with after 20 (113.1 v. 28.2 cases per year). A similar twofold increasing trend was noted for females (12.7 v. 7.4 cases per year). Contributory factors to suicide risk in young adults in Ireland included bereavement, relocation, relationship break-up, bullying and assault. ^{Reference Malone3} Inoue & Fujita propose that bullying is a factor that should be explored in tandem with studies of youth suicidality. This is supported by a growing evidence base internationally that bullying is a key antecedent for suicide, particularly when experienced at an early age. ^{Reference Geoffroy, Gunnell and Power4}

Suicide rates and associated risks vary across countries and cultures. There is a need for regional suicide research to understand the complexities specific to suicide within nations as well as larger-scale, international, cross-centre research to continue to build a robust evidence base on this issue. Future suicide prevention programmes may need to be revised and tailored to address the needs of specific age groups. ^{Reference Malone3} Targeted, high-priority suicide prevention strategies can work when based on robust national and international research; evidence for this can be seen in the UK where suicide rates have been in decline over the past 5 years, coinciding to a degree with the implementation of the National Suicide Prevention Strategy. ^{Reference Mok, Kapur, Windfuhr, Leyland, Appleby and Platt5} However, suicide prevention remains a moving target - the recent national confidential inquiry into suicide in the UK does support a fall in suicide rates between 2001 and 2010 as well as a fall in male suicide rates under the age of 25, but it also showed a possible increase in suicide rates among mental health patients in 2011. ^{Reference Appleby, Kapur, Shaw, Hunt, While and Flynn6} This reiterates the point that the focus of prevention should potentially be group specific, depending on the needs of the population involved.