ADHD and addiction: the hidden link in undiagnosed adults

In my clinical practice, I frequently see the same pattern emerge. Someone comes to therapy because they’re struggling with alcohol use, substance use, gambling, excessive social media use, or compulsive sexual behaviour. But as the work progresses, another story begins to appear alongside it – not simply addiction, but years of living with an unrecognised neurodivergent mind.

ADHD can be clinically associated with substance misuse issues in academic literature; a 2023 meta-analysis of 31 studies (Rohner et al., 2023) estimated that ADHD is present in about 21% of people with substance use disorder, and a 2023 expert consensus statement (Young et al., 2023) confirmed that ADHD is frequently co-diagnosed with substance use and substance use disorder.

This is not to say that every person with ADHD will develop an addiction, nor that addiction can be explained by ADHD alone. Trauma, shame, grief, burnout, family dynamics, and social context can all have an impact. However, in some adults, particularly those who have gone undiagnosed for years, ADHD can be the missing piece that finally explains how they cope.

Why undiagnosed ADHD can cause addictive coping

Undiagnosed ADHD frequently causes a kind of unseen strain. From the outside, the person may look capable, intelligent and high-functioning. On the inside, they may be dealing with chronic overwhelm, mental restlessness, impulsivity, intermittent focus, emotional intensity, or a lifelong belief that ordinary life takes more work from them than it seems to require for other people.

Over time, many people find something that gives temporary relief. Alcohol may quieten the internal noise. Drugs or other stimulants may briefly create a feeling of clarity, control, or vigour. Gambling may provide both urgency and stimulation. Compulsive pornography use, gaming, or endless online novelty might provide a quick distraction, reward, or escape.

From the outside, these behaviours may appear to be reckless or self-destructive. From the inside, they, however, often make emotional sense. They could be crude, costly methods of regulating a system that has been under stress for a very long period.

This is an important distinction. When we understand addictive behaviour solely as “bad choices”, we frequently overlook the role that it is serving. In therapy, one of the most important questions is not only “How do we stop this behaviour?” but also “What does this behaviour do for you that nothing else has managed to do?”

Why do many adults get diagnosed with ADHD late?

Many adults with ADHD were not diagnosed in childhood because they were bright, articulate, or seemingly well-behaved in class. Others developed coping strategies strong enough to conceal their difficulty for years. They got through school, work, or relationships, but often at a high internal cost.

Late diagnosis is common. According to a 2024 CDC report (Staley et al., 2024), an estimated 15.5 million U.S. adults are currently diagnosed with ADHD, and about half said that they were first diagnosed in adulthood. CDC also notes that some adults may have ADHD and never have been diagnosed at all.

By the time addiction enters the scene, the original neurodivergent experience is often buried under years of shame and self-blame. People rarely arrive saying, “I think I may have ADHD.” More often, they say, “I don’t know why I can’t stop.”

That question is clinically significant. Sometimes the answer does involve trauma, loss, or relationship pain. But sometimes the answer is also neurological: the person has spent years trying to manage an ADHD nervous system without understanding what it needed.

How does this affect therapy and treatment?

This is important because addiction treatment might be ineffective when the underlying neurodivergence is not taken into account. If the (mal)adaptive behaviour is taken away without understanding the function it provided, the person may be left with the same dysregulation, distress, or inner chaos that motivated this behaviour in the first place.

In other words, if someone stops drinking but lacks the ability to relax their mind, rest their body, tolerate boredom, organise their day, manage emotion, or access healthy stimulation, the probability of relapse becomes much higher.

This is why accurate assessment is important. NICE has specific guidance covering the assessment, recognition, diagnosis, and management of ADHD in adults, and NIMH notes that accurate diagnosis is important when substance use and mental health difficulties overlap because symptoms can be missed or confused.

In practice, that means therapists should hold two pictures in mind at once, one being the addiction itself, and secondarily, the neurodevelopmental context in which it may have emerged. We want to understand not only what the person is facing challenges with, but what problem their maladaptive behaviour seemingly solved for them.

Questions frequently leading to this

In my experience, generic addiction questions do not always get to the heart of it. More useful questions could include:

• When did you first realise that you had to work harder than everyone else just to keep up?
• Did school feel like learning, or did it feel like constant performance management?
• When did you last feel genuinely rested?
• Have you spent years being called too much, too distracted, too intense, too sensitive, too quiet, or simply “not trying hard enough”?
• When you use a substance or behaviour, what changes in your body or mind afterwards?

These questions move the attention away from moral judgment and towards lived experience. This is often where the real clinical picture begins to emerge.

What recovery can look like

When ADHD is finally identified, whether via formal diagnosis or through careful clinical observation, the person’s story often changes. The question shifts from “What is wrong with me?” to “What have I been trying to cope with all this time?”

This shift can be powerful. It does not erase the harm addiction may have caused, and it does not obviate the need to work towards recovery. However, it can reduce shame, increase self-understanding, and make treatment more realistic and compassionate.

Some individuals need practical support with emotional regulation, distress tolerance, structure, and habits. Others require space to understand what the addiction has protected them from emotionally. Most people require both.

Therapy can still be useful for people who are awaiting assessment or cannot currently access one. A formal diagnosis can be useful, but insight does not have to wait for paperwork. If the pattern is there, it can still be explored with care, humility, and clinical responsibility.

If you are reading this and recognising yourself here, the important thing to know is this: struggling with alcohol, drugs, gambling, or compulsive behaviours does not mean you are weak, broken, or otherwise lacking discipline. Sometimes, addiction is not the first problem. Sometimes it is the solution a person found before they had better ones. When this is the case, recovery usually begins not with more shame, but with understanding.

References

Rohner, H., Gaspar, N., Philipsen, A., & Schulze, M. (2023). Prevalence of Attention Deficit Hyperactivity Disorder (ADHD) among Substance Use Disorder (SUD) Populations: Meta-Analysis. International journal of environmental research and public health, 20(2), 1275. https://doi.org/10.3390/ijerph20021275 

Staley, B. S., Robinson, L. R., Claussen, A. H., Katz, S. M., Danielson, M. L., Summers, A. D., Farr, S. L., Blumberg, S. J., & Tinker, S. C. (2024). Attention-deficit/hyperactivity disorder diagnosis, treatment, and telehealth use in adults — National Center for Health Statistics Rapid Surveys System, United States, October–November 2023. Morbidity and Mortality Weekly Report, 73(40), 890–895. doi.org 

Young, S., Abbasian, C., Al-Attar, Z., Branney, P., Colley, B., Cortese, S., Cubbin, S., Deeley, Q., Gudjonsson, G. H., Hill, P., Hollingdale, J., Jenden, S., Johnson, J., Judge, D., Lewis, A., Mason, P., Mukherjee, R., Nutt, D., Roberts, J., Robinson, F., … Cocallis, K. (2023). Identification and treatment of individuals with attention-deficit/hyperactivity disorder and substance use disorder: An expert consensus statement. World journal of psychiatry, 13(3), 84–112. https://doi.org/10.5498/wjp.v13.i3.84