Your 15-year-old son may be a bit daft but the chances are he is a lot less emotionally distressed than his female equivalent. In fact, a new study suggests that 15-year-old girls – and especially offspring of the class of person who reads this paper – are probably the most mentally ill single group of people in the whole country: a staggering 43% of them are seriously emotionally distressed (ie mildly depressed or anxious) and 27% are suffering a full-scale major mental illness (severe depression or anxiety).
The study showing this also demonstrates massive increases in girls' distress since 1987. Originally, they measured levels of anxiety and depression in two very large (2,000-plus) representative samples of 15-year-olds, one in 1987 and the other in 1999.
Among the bottom social class, girls' distress rates rose only a little but in the top class, the rise was from 24% in 1987 to a startling 38% in 1999 – more than one third of the most privileged and successful. Contrary to popular perceptions of a teenage male emotional apocalypse, there was a far less significant increase in problems among boys, (from 17% to 19%) but for the privileged girls, rates of the kind of distress that can require hospitalisation rose threefold (from 6% to 18%).
Now the researchers have done a further study finding that in 2006, girls from the top social class had continued to increase their rates of distress, reaching 43%. But the horrifying additional bad news is that the girls from lower classes have almost caught up with their more privileged sisters, with rates of 41%.
The rise among girls from affluent homes between 1987 and 1999 coincided with a period in which girls began to outperform boys in almost every academic subject at every educational stage. In 1987, there was virtually no difference in how well the genders did at GCSE level, but by 1999 a gap had opened: whereas 43% of boys got five or more at grades A to C, 53% of girls did so in 1999. The greater success of the girls was accompanied by increased emotional distress.
The researchers showed that affluent girls found the time leading up to exams most stressful, and this difference from boys arose after 1987. In the three months before exams, increased distress was more likely only among the high-income girls, and only in 1999. More generally, the main worries troubling high-income girls were family problems, schoolwork, exams and their weight.
These pressures may have continued to increase, but the fascinating question is why less privileged sisters are now almost as distressed: what new social toxins could have had this effect between 1999 and 2006?
There is a long list of candidates: laddette culture, Wags as models (with Victoria Beckham consistently the girl they most want to be during this era), rampant consumerism (placing too high a value on money, possessions, appearances and fame) and a massive sense of relative deprivation – always feeling you deserve better than what you have got, be that your boyfriend, MP3 player or your body. This was the It Could Be You era, one stoked by the advent of reality television in which girls such as Jade Goody, who would never have had a chance in previous times, became rich and famous just for appearing on Big Brother.
It remains to be seen whether these were the key factors and whether they had as much impact on the daughters of Guardian readers. Of only one thing can we be sure: the pressure on 15-year-old girls is phenomenal.
• Sweeting, H et al, 2009, Social Psychiatry and Psychiatric Epidemiology, 44, 579-86. More Oliver James at selfishcapitalist.com