Language disorder and internalizing mental health problems in youth offenders: A systematic review.

Only eight studies met the inclusion criteria, and the reviewers could not pool the results because the studies asked different questions and used different tests. Six were rated moderate quality, one weak and one high, so the evidence base is thin and uneven. Half of the included studies never reported whether the young people with language disorder also had anxiety or depression, so the review's main question could not be answered at all. The studies used a wide range of language tests, and two measured language using part of an intelligence test. Several assessed mental health with brief screens in which depression or anxiety was only one section. The authors say these tools may not have been detailed or sensitive enough to pick up the full extent of either problem. Every mental health measure relied on self-report. Young people in the justice system have been reported to hide difficulties to appear less vulnerable, and alexithymia, reported in around 30% of youth offenders, makes it hard to identify and describe emotions, so the anxiety and depression figures are probably underestimates. 92% of the participants were male, so the review says almost nothing about young women, who may be more likely to have internalizing problems. Over half the participants (52%) had another condition such as conduct disorder, ADHD or traumatic brain injury, which makes it hard to tell whether language or something else is behind the findings. The measures were developed for Western populations and only one study deliberately recruited a culturally representative sample, even though Indigenous and culturally and linguistically diverse young people are over-represented in justice systems. Only English-language studies were included, and the review protocol was not registered.

The article text provided does not include a funding statement or a declaration of competing interests, so it is not possible to say who paid for this review or whether the authors declared any conflicts.

Do not take this review as evidence that language disorder and anxiety or depression go together in young offenders. The authors write that the two tend to occur together, but their own limitations section says the evidence on how much they co-occur is inconclusive, half the included studies never reported mental health by language ability, and the only two studies that tested the relationship found nothing.