About 1 in every 10 people in the US who uses Adderall or similar combination drugs to treat attention-deficit/hyperactivity disorder (ADHD) has been affected by an ongoing shortage, a new analysis suggests.

The US Food and Drug Administration announced that Adderall was in shortage in mid-October 2022, and the share of people with ADHD who filled their prescriptions for Adderall and related medications plunged in the following months.

In an exclusive analysis for CNN, data from the health data platform Truveta shows that the prescription fill rate for amphetamine/dextroamphetamine medications fell from nearly 49% in October 2022 to a low of less than 41% in February 2023. Overall, the average monthly prescription fill rate was 11% lower in the first half of 2023 than it was in the first half of 2022, and it did not show steady signs of improvement through the end of 2023.