The Rise: Age 16 and 17

The Rise: Age 16 and 17

Note: this is part of the Youth Suicide Rise project.

In The Rise: Age Trends we saw that suicide rates of younger kids increased more than those of older kids, and although this applied mainly to younger teen versus older teen age groups, there was also evidence that rates grew more for kids aged 16 than 17.

Let us now look closer at ages 16 and 17 by adding data from 2018 and then asking if the are are distinctions between boys and girls and what were the trends before The Rise.

First we will compare 3-year and 5-year aggregate suicide counts:

	2005-2007	2016-2018	Difference	Proportional		2003-2007	2014-2018	Difference	Proportional
Boys 16yo	525	859	334	64%		899	1308	409	45%
Boys 17yo	726	1032	306	42%		1192	1630	438	37%
Girls 16yo	167	351	184	110%		293	543	250	85%
Girls 17yo	168	318	150	89%		274	485	211	77%

We see that the increase was proportionally greater for boys and girls age 16 than age 17, be it by comparing 3-year or 5-year periods.

There is, however, a catch: the pattern nearly disappears for boys and reverses for girls when we compare just 2018 with 2007:

	Year 2007	Year 2018	Difference	Proportional
Boys 16yo	174	293	119	68%
Boys 17yo	226	363	137	61%
Girls 16yo	55	109	54	98%
Girls 17yo	41	104	63	154%

To understand the situation better, let us first look at the yearly ratio between suicides of boys age 17 versus 16:

We see that the ratio was high in 2005 and 2006, as well as 2008, so that 2007 is a local minimum.

As to long-term trends, until about 2008 the ratio appears to be increasing rather than decreasing, so the decline during much of The Rise is not a continuing trend from before (though due to the major fluctuations we should treat any such trends with caution).

As with boys, the ratio is very high in 2005 for girls:

The long-term trend, however, seems to be almost linear throughout the millennium: a slowly declining ratio subject to massive fluctuations in the first decade (thus again the trend should be treated with caution).

To summarize: the data is compatible with suicide rising faster among 16-year-old boys -- but due to high fluctuations it is difficult to link this trend to The Rise itself.  As to girls, the fact that suicide tends to peak at 16 rather than 17, coupled with massive fluctuations in the first decade, make any conclusion about general trends there very tenuous.

Notes:

The fluctuations often appear to be close to oscillations:  an increase is quickly followed by a decrease.  While this could be mainly due to random fluctuations being subject to the 'reversion to the mean' rule, it is interesting to note that the female 17 vs 16 ratio has been fairly stable since 2011 despite suicide being much less common among girls.

One possibility is that the oscillations are partly due to what we may call the Depletion Theory: the notion that being suicidal is the result of complex factors while suicide itself often appears to be 'triggered' by some event to which, however, those not already highly suicidal seem to be immune.

If this theory is close to reality, then if an event like The Great Recession triggers older teens more than younger teens there would eventually be a 'depletion' of the most suicidal older teens and thus the average suicide age of kids would first greatly increase but soon after greatly decrease.

The same would apply to oscillations of boys vs girls ratio and between other groups.

We will see later to what degree such a theory is compatible with data -- e.g. if being suicidal is less volatile than suicide itself and so on.

Technical note:  we used only second-degree polynomial to see if there is a significant distinction in trends between the decades (as it appears to be the case for boys but not for girls).