New research explores why ADHD often leads to other mental health issues

By Dr. Bob Carey

Recently, I read a longitudinal study titled "Identifying Candidate Mediators Linking ADHD Symptoms and Internalising Problems in Adolescence," researchers Murray, Dryburgh, and Sonuga-Barke (Murray AL, Dryburgh K, Sonuga-Barke EJS. Identifying Candidate Mediators Linking ADHD Symptoms and Internalising Problems in Adolescence: An Exploratory Longitudinal Mediation Analysis. J Atten Disord. 2026 Mar 6). This study explored the complex pathways that lead from ADHD symptoms to internalizing issues like anxiety and depression during the critical teenage years. The study found social difficulties, emotional dysregulation, and academic struggles mediate the relationship between ADHD and later mental health problems.  They reported that adolescents with ADHD may develop secondary mental health conditions due to repeated stress, rejection, or academic failure.  The significance of these findings emphasizes the importance of early psychosocial supports (not just medication) for ADHD.  The study also suggests interventions targeting social skills and emotional regulation that may prevent secondary disorders.

This research is particularly poignant for the families I work with, as it highlights that the challenges of ADHD rarely exist in isolation. Instead, the study suggests that the "disruptive" symptoms we often focus on in ADHD—impulsivity and inattention—can create a ripple effect through a child's social and academic life, which in turn fuels emotional distress. By tracking adolescents over time, the authors identified that social difficulties and academic setbacks act as key mediators; essentially, the ADHD symptoms create "systemic" friction that eventually manifests as internalizing problems.

These findings carry profound implications for how we support our children. If we only treat the ADHD symptoms as a checklist of behaviours to be "fixed" or suppressed, we may be missing the very mechanisms that lead to long-term emotional struggles. The research underscores the necessity of a proactive approach that looks at the child's entire environment. It suggests that by intervening in the social and academic systems where these children feel the most friction, we can potentially prevent the development of secondary mental health issues. This shifts our goal from mere compliance to the holistic protection of a child’s emotional well-being, recognizing that their internal world is often a reflection of the successes and failures they experience in the world around them.

The insights from this study are remarkably consistent with the Positive Systems Approach (PSA) I have outlined in my work. In my clinical experience, and as I detail in my latest book (What if it’s not Just the Behaviour?), we must view the family not just as a group of individuals, but as the primary "operating system" for a child’s development. When we are supporting a child with ADHD, we have to acknowledge that the resulting friction often leads to chronic family stress. This stress acts like a "drain" on a parent’s emotional bandwidth. I often see parents struggling with what I call a "shorter fuse" or "emotional numbness," where they are physically present but find it nearly impossible to remain "emotionally available" because their own capacity to regulate is depleted.

The Positive Systems Approach (PSA) encourages us to address this proactively by prioritizing "Family Health". This isn't about being a "perfect" parent; it’s about recognizing that a child’s ability to regulate their emotions is profoundly shaped by the stability and health of the family unit. When we manage our own stress and seek support, we are effectively repairing the "system" so we can provide the calm, consistent co-regulation our children need to navigate their internal storms. One of the most powerful proactive tools we have is "Non-Contingent Reinforcement"—flooding our home with positive attention, affection, and shared laughter just because the child is part of the family, not only when they "earn" it. This builds a foundation of safety and security that naturally reduces the child’s need to use disruptive behaviour as a way to get noticed or connect. 

This proactive mindset must also extend to the educational system through what I call "Portability". If a strategy works in the living room, we should build a bridge to ensure it is also being used in the classroom so the child experiences a consistent environment wherever they go. Instead of relying on punitive measures that often trigger the "Security Guard" amygdala, we should advocate for systemic "Environmental Modifications". This might mean working with teachers to allow for sensory breaks, using visual schedules for transitions, or offering alternative ways to complete assignments. By proactively changing the classroom "system" to reduce overwhelm, we are not just managing behaviours; we are teaching the child functional skills—like how to use a "cool-down" spot—that will serve them for a lifetime.

Finally, we must look at the broader community and peer systems that influence our children. As a psychologist, I’ve seen how peers can either "fuel the fire" of disruptive behaviour or act as a "mirror" for positive growth. A child who feels "seen and safe" at home is naturally more resilient to negative peer pressure. By adopting "Systems Thinking," we move away from trying to "fix" the child in isolation and instead ask what supports are missing in their community or school that would make positive behaviour easier. When we proactively strengthen the health of the family, align our educational supports, and nurture positive social connections, we are "playing the long game". We aren't just looking for short-term compliance; we are creating a sustainable, nurturing environment where a child’s emotional well-being is the ultimate measure of success.

At its core, PSA moves us from a mindset of "control" to one of "connection," viewing behaviour as a form of communication rather than a random act of defiance. The study’s identification of "mediators" like social friction perfectly mirrors the PSA concept of "Systems Thinking," which teaches us that a child’s behaviour is deeply influenced by the interconnected "systems" they inhabit—their families, schools, and peer groups. When a child with ADHD struggles, PSA encourages us to look at these external systems to see where we can make "Environmental Modifications" to reduce triggers and foster success.

Comments regarding this study from Dr. Makami (University of British Columbia) to Global News included:  “I think that kids who have ADHD symptoms, they are commonly being told or they think that they’re bad kids because they’re getting in trouble a lot at school, at home. Their peers often don’t like them. They’re often told, ‘You need to try harder; you’re not applying yourself. You need to listen…. So I feel like over time, that can really take its toll.“

When we consider the weight of these long-term emotional challenges, the insights of Dr. Amori Mikami become incredibly relevant. She points out that children with ADHD are frequently told—or begin to believe—that they are simply "bad kids" because they are constantly in trouble at school or at home. Over time, being told to "try harder" or "just listen" when their brains are wired differently takes a significant toll on their self-esteem. In the Positive Systems Approach (PSA), we recognize this as a "Reputation Trap," where a child begins to internalize a negative label and plays into that role because it feels like who they are expected to be.  This is why PSA shifts the focus from "fixing" a "bad kid" to becoming "curious detectives" who look for the "why" behind the behaviour. Instead of viewing a child's struggles as a lack of effort, we see behaviour as communication—often a signal that the child is overwhelmed, bored, or lacking the specific coping skills needed for a situation. Dr. Mikami’s observations highlight the "social reward" or "clown culture" that can emerge when a child feels rejected by peers; they might act out to get any form of attention, even if it’s negative, because they haven't felt the "human reward" of genuine connection.  To counter this "toll" that Dr. Mikami describes, PSA emphasizes "Non-Contingent Reinforcement"—flooding a child with positive attention, affection, and "catch-you-being-good" moments that are not tied to their performance. By providing this "high-intensity" positive input before a crisis even begins, we help rebuild their sense of self. We move from a system of "control and compliance" to one of "connection," ensuring the child feels "seen, safe, and supported" at home. When we change the system's response to the child, we foster an environment where they no longer feel like a "problem to fix," but like a valued member of a team who is simply learning how to navigate the world with a unique set of tools.