How Do Meds Affect the Developing Brain? Even Long-term Studies Can’t Say
What does it feel like to grow up taking psychiatric meds? That’s the question that has occupied me for the past couple of years. Naturally, it feels different to different people, but overall I’ve found that meds seem to introduce a lot of extra uncertainty into the process of coming of age.
There are a lot of ways that meds make growing up more complicated, and I’ll explore those in future posts. But one big factor has to do with the lack of info, from a scientific perspective, about meds’ effect on developing brains and bodies.
We can’t answer the question of how medication affects development because even studies that follow people starting at a young age often aren’t designed to distinguish between long-term effects of having a psychiatric disorder like ADHD or depression and the long-term effects of taking medication to treat that disorder.
A recent study about childhood ADHD leaving its mark on the brain provides a good example.
The study, which came out in the latest issue of the Archives of General Psychiatry, is notable because it followed boys with ADHD for 33 years, well into middle-adulthood. These kind of long-term studies are expensive, time-consuming and complicated to conduct, but they’re crucial for measuring the impact of different disorders over time. So, kudos to the researchers for pulling off this kind of sustained analysis.
Previous studies have found relative reductions in overall brain volume in both kids and adults with ADHD compared to those without. In particular, they’ve showed reductions in parts of the cerebral cortex, or “gray matter,” thought to be implicated in ADHD. This analysis showed that people diagnosed with ADHD as children had less gray matter than non-ADHD controls – and those with persistent symptoms had less of it than those whose symptoms had remitted.
But the study has one shortcoming for those of us who want to know what role medication might play in these brain anatomy abnormalities. Ninety-seven percent of the ADHD subjects were treated with methylphenidate (Ritalin) as kids, which doesn’t leave enough for a reasonable comparison group of non-Ritalin takers (all of the subjects were also male and white). And the subjects’ brains were only scanned when they were adults, meaning it’s not possible to compare before-and-after effects of taking Ritalin.
The researchers acknowledge this limitation, and cite one study that showed less cortical thinning in ADHD kids who took stimulants than those who didn’t. From those results, we might extrapolate that if the kids in this latest study hadn’t taken Ritalin, maybe they would have even less gray matter. But there’s no way to know for sure.
I’ve seen this same “is it the disorder, or is it the meds” problem in a bunch of long-term ADHD studies. With more awareness about medicated kids, I’m hoping that more recent studies – i.e. those not begun in the 1970s, like this one – will be able to take meds into account.
That still wouldn’t tell us much about what effect the meds had on brain development. But it would be one more piece of the puzzle, not just for scientists, but for the millions of young adults who took ADHD medication at some point in their lives and wonder what its long-term effects might have been. Do any of you fall into that category?
image credit: http://intramural.nimh.nih.gov
Bell Barnett, K. (2011). How Do Meds Affect the Developing Brain? Even Long-term Studies Can’t Say. Psych Central. Retrieved on July 4, 2015, from http://blogs.psychcentral.com/my-meds/2011/11/how-do-meds-affect-the-developing-brain-even-long-term-studies-cant-say/