Researchers studied a specific brain signal, called P50 sensory gating, in teenagers. They wanted to see if this signal was different in teens who engage in non-suicidal self-injury (NSSI), especially those who also have symptoms of depression. The study included 86 adolescents with NSSI and 50 healthy teens for comparison. The teens with NSSI were split into two groups: 55 who had depressive symptoms and 31 who did not.
The main finding was that the teens with NSSI and depressive symptoms showed differences in their P50 brain signal compared to the healthy teens. Specifically, their brains showed a weaker ability to filter out repeated sounds. This weaker filtering was linked to having more severe depression symptoms. It was also linked to slightly worse performance on a puzzle-like task that tests planning and memory.
It is very important to understand what this study does not show. This was an observational study, which means it can only find links or associations. It cannot prove that the brain signal differences cause self-harm or depression. The study was also relatively small. The brain signal measured is a research tool and is not used by doctors to diagnose or treat these conditions. More research is needed to understand if these findings are meaningful for helping teens in the future.