Research suggests adult ADHD often goes undiagnosed until addiction develops
As awareness of adult ADHD increases, addiction specialists are reporting a pattern that is becoming increasingly difficult to ignore. Many people entering residential drug and alcohol treatment are only discovering they have ADHD once they are already in recovery.
Research suggests the overlap is significant. Around one in five people in substance misuse treatment meet the criteria for ADHD, yet many were never diagnosed earlier in life. Instead, substance use often escalates quietly, long before ADHD is recognised.
Michael Williams, a treatment manager working in residential addiction care, says this is a familiar scenario.
“ADHD doesn’t always look obvious in adults,” he explains. “People often develop coping strategies that allow them to function at work or in relationships. Internally, though, they may struggle with impulsivity, emotional regulation, sleep, and constant mental restlessness.”
For some, alcohol or drugs initially appear to help. Substances may slow racing thoughts, ease anxiety, or improve focus. Over time, what begins as coping can turn into dependence.
“By the time someone reaches treatment, ADHD has often been part of the picture for years,” Williams says. “It just wasn’t recognised.”
One reason the risk goes unnoticed is that addiction rarely appears overnight. Many people describe a gradual escalation, a drink to switch off, cannabis to calm anxiety, stimulants to stay focused. Each step feels rational at the time.
Once substance use becomes the main issue, ADHD symptoms can be misattributed entirely to addiction. Difficulty concentrating, mood swings, and impulsivity are often treated as consequences of substance misuse rather than signs of an underlying neurodevelopmental condition.
It is often only in recovery, when someone is sober and stable, that these patterns become clearer.
“When ADHD is identified, treatment changes,” Williams explains. “Recovery becomes less about willpower and more about understanding how someone’s brain works. That shift can be a turning point.”
Specialist providers such as Abbington House are increasingly highlighting the link between adult ADHD and addiction, calling for better recognition earlier in life.
As adult ADHD diagnoses rise across the UK, treatment professionals say the focus should not just be on assessment waiting lists, but on what happens when ADHD is missed entirely.
“If substance use is sometimes an early signal of undiagnosed ADHD,” Williams adds, “then earlier recognition could prevent a lot of harm later on."