The Opposite

 RFKJr, among many other myths that he believes*, thinks psychiatric meds are contributing to the high-profile shootings we've been seeing, and thinks we should "look into it." Well, this is only one study in Sweden, but it does have an N=247,420 with robust results. Prescribing ADHD medication resulted in lower adverse "real world outcomes" such as self harm, traffic crashes, and crime. Interestingly, the effect seems to be weakening over time as the number of prescriptions increases. 

In this longitudinal population-based study of 247 420 individuals using ADHD medication between 2006 and 2020, we consistently found ADHD medication to be associated with lower rates of self-harm, unintentional injury, traffic crashes, and crime across all analyzed time periods, age groups, and sexes. However, magnitude of associations between ADHD medication use and lower risk of unintentional injury, traffic crashes, and crime appear to have attenuated over time, coinciding with an increase in prescription prevalence during the same period. The weakening trends for unintentional injury and traffic crashes were not fully explained by changes in age and sex distribution of the medication users, whereas the trend for crime was no longer statistically significant. These findings suggest that the declining strength of the associations of ADHD medication and real-world outcomes could be attributed to the expansion of prescriptions to a broader group of individuals having fewer symptoms or impairments.

My guess on this reveals one of my biases, but it may turn out to be true in this case. A broad range of interventions pick off the low hanging fruit at first, whether this be in medicine, education, economics, or crime. As this success is experienced by the doctors, politicians, or teachers, they try the solution on a wider group that less-obviously fits the the category and surprise! It doesn't work as well on every Tom, Dick, and Harry. The Law of Diminishing Returns. I used to see this in mental health, where an intervention like ECT's would work spectacularly well on some people with depression, but treatment-refractory patients of many diagnoses would eventually end up at the "shock treatment" door, because patient, family, and prescribers were all frustrated and willing to try less-likely interventions.

*The current fallback argument by his supporters are that the CDC and the medical establishment badly needs disruption and he is supplying disruption, so shut up, you liberal weenie. I find this unconvincing. Just because an institution needs to be disrupted does not mean that any particular disruptor is on the right track. Not all disruptions are equally valuable. Saruman wanted to disrupt Mordor, after all.