ADHD Diagnosis – Implications from Childhood to Adulthood: A Special Report

This report is Part 3 of a special Psycom Pro series on the external factors that affect ADHD diagnoses and treatment outcomes. Part 1 explores how race and culture can impact the acceptance of an ADHD diagnosis__. Part 2 explores how adverse childhood experiences, trauma, and parenteral stress play a role in obtaining an accurate ADHD screening. See also, our clinical primer on the most accurate ADHD assessment tools.

Attention deficit hyperactivity disorder (ADHD) is a chronic condition that has far-reaching implications based on the disease trajectory and duration. From childhood to adulthood, academic achievement, employment, finances, and overall quality of life (QoL) may be impacted.¹˒²

Evidence indicates that complex interactions between disease severity, co-existing mental health disorders, and treatment outcomes serve as crucial predictors of disease persistence long-term.³ Yet, definitions of disease criteria used to categorize diagnosis, assessment, rates of disorder continuance and remission lead to variability in reported prevalence data and long-term effects.³⁻⁶ For example, one study found adhering to strict criteria yielded persistence rates of nearly 50%.⁷

Other prevalence studies show:⁸˒⁹

• Approximately one-third of children with ADHD achieve remission and have relatively unaffected function in adulthood while the balance (two-thirds) continue to have some degree of symptom persistence

• 15% of those diagnosed with ADHD have continued symptoms at age 25, while 65% of individuals deal with some symptoms in adulthood.

Variances in research findings pertaining to rates of disease prolongation into adulthood also point to complex genetic and socio-environmental elements, such as childhood adversity and other comorbid factors.⁵˒¹⁰˒¹¹ Higher rates of childhood ADHD impairment are also associated with greater adult persistence.⁵ Recent studies further highlight the existence of distinct differences in child versus adult ADHD symptoms which are not reflected in the DSM-5; researchers point to the need for separate ADHD diagnostic criteria for adults.¹²˒¹³

According to Caroline Buzanko, PhD, a registered psychologist, speaker and ADHD expert, symptoms of ADHD will look different at different ages throughout the lifespan. Dr. Buzanko, who serves on the Psycom Pro Editorial Advisory Board, noted that “it’s important for clinicians to incorporate functional analysis with symptom rating to better understand how ADHD symptoms can cause daily life functional impairments (eg, family, academic, social, work performance)…Ideally, you want to have a practical definition of the symptoms, which translates into functional everyday behavior.”

In addition, Dr. Buzanko highlighted diagnostic constraints with the DSM criteria which clinicians need to consider during assessments.

Some of the limitations she noted include:

• not appropriate to all ages

• no age references for symptom cut-offs

• not sex-referenced

• age of onset has no validity

• behavioral and emotional impulsiveness is missing

• lack of definition of what constitutes impairment across two settings

• developmental deviance is not defined

She added, “We cannot base decisions on parent reports because they might not know what their child is really like compared to same-aged peers.”

Executive function which refers to neurocognitive self-regulation of thoughts, actions, and behavior (eg, organizing, planning, working memory, and inhibition) has been found to be impaired in individuals diagnosed with ADHD and has negative implications associated with academic, social, risk, and life activities.¹⁴˒¹⁵ Data shows that executive function deficits in adults with persistent ADHD symptoms lead to long-range difficulties with functional life outcomes.¹⁶˒¹⁷

According to Chris A. Zeigler Dendy, MS, an ADHD expert, author, and speaker, “Children with ADHD have between a 3- to 5-year delay in brain maturity including executive functions such as organizational skills and emotional development. As a result, children experience a 30% delay in development of functional living skills that impact their behavior both at home and school.”

Neurodevelopmental disorders like ADHD compromise executive function which contributes adversely to decision making, self-control, and behavior regulation.¹⁸ Executive function deficits increase burdens on learning, and academic success.¹⁹

Children with ADHD reach developmental milestones later than average. For example, Dendy explained, a 12-year-old is more like a 9-year-old with regard to developmental maturity. “So, teachers and parents expect more of our children than they are capable of doing.” These expectations can be especially challenging during critical developmental phases – such as adolescence – and require additional support from caregivers and teachers for successful transitions.

Children with ADHD often face academic challenges from internal and external sources which are incongruent with their intellectual capabilities.²⁰ Studies suggest they are less likely to graduate high school or complete post-secondary education.²¹

A 2020 study of Scottish school children by Fleming and colleagues found that children with neurodevelopmental disorders frequently have multiple co-existing morbidities – such as ADHD, depression, intellectual disability, autism spectrum disorder (ASD) – which, along with socio-emotional challenges, substantially impacts academic outcomes and long-term achievements.²² Clinicians focusing solely on one disorder may miss opportunities to address the impact of co-occurring conditions that lead to poor outcomes in school and long-term functional QoL.²²

Dendy mentioned that, due to delayed brain maturity noted above, young adults with ADHD are sometimes referred to as “late bloomers.” Adolescents with ADHD may not be developmentally mature enough to succeed in post-secondary education due to feeling overwhelmed which may damage their self-worth. She went on to say, this is why “parents and treatment professionals may often encourage individuals to take a ‘gap year’ or attend a local community college after high school graduation.”

Individuals with ADHD face difficulties with peer interactions and friendships, which negatively affects social-emotional functioning into adulthood.²³ Peer communication and relationships are essential for self-worth, growth, confidence, and identity. Reports suggest that 50 to 80% of children with ADHD face peer rejection in social interactions – this rejection can have long-lasting effects.²⁴

There are disparate reports on the impact of an ADHD diagnosis in childhood and psychosocial function long term. For example, a 2020 study of Irish children by O’Connor and McNicholas examining the impact of an ADHD diagnosis found that children diagnosed at 9 years old exhibited greater difficulties with socioemotional interactions and had poorer self-concept by age 13.²⁵ However, other global studies have determined that undiagnosed ADHD can also negatively impact self-worth and peer socialization.²⁶

There is also mixed evidence on differences in peer functioning and influence among boys and girls. Some data show that girls may experience distinctly different challenges including higher levels of bullying and peer victimization, while other reports indicate that boys with ADHD are more vulnerable to peer interactions.²⁷˒²⁸

Adolescents with ADHD may also engage in harmful behavior patterns including delinquency, reckless driving, and/or substance misuse due to impaired cognitive and executive function deficits.²⁹˒³⁰ The data is unclear on whether peer influences may also be a factor.

Overall, these data may provide relevant context for consideration during ADHD screenings and neuropsychological assessments.

Given that clinical interventions may modify the course trajectory of ADHD severity and persistence, it is imperative academic, family, and social sources of stress be identified early. In addition, the implementation of coping strategies can be crucial to improving life functioning skills.³¹

The ADHD Life Transition Model advocates for recognition of ADHD as a chronic condition that yields shifting symptoms based on developmental life phases. Adoption of this approach may advance clinical criteria for symptom recognition and treatment success long term.³²

According to Dendy, “Children don’t outgrow ADHD; the brain continues maturing until the early 30s, so the child learns new skills while adapting and compensating for executive function deficits. Parents and teachers should have realistic expectations based on the 3-year brain maturation delays.”

Practically speaking, she emphasized that both parents and teachers need to provide longer-term support and accommodations for children with ADHD than their peers. “It’s important for children with ADHD to have strategies to address stress and anxiety in academic and life situations. This will ultimately ensure long-term success managing their symptoms and enjoying their life,” said Dendy.

Dendy suggests these additional strategies for caregivers and educators of children and adolescents with ADHD:

• Anticipate and plan ahead to avoid potential problems

• Use rewards to improve behavior before punishment

• Provide affirmations or praise when the child behaves appropriately

• Provide external reminders they can see or hear

Heidi Feldman, MD, PhD, a Ballinger-Swindells Professor of Developmental and Behavioral Pediatrics at Stanford University School of Medicine, offered some additional tips when addressing ADHD behavior:

• Look for the child’s strengths – “It is easy for parents and educators to focus exclusively on the weaknesses and challenges a child brings to home or school. It is easy for the adults to shame and humiliate the child.”

• Acknowledge their contributions

• Value academic and social participation

Dr. Feldman suggests that caregivers “see how far that goes into reducing the frequency and intensity of problem behaviors.”

Dr. Buzanko also pointed out that, “ADHD is a disorder of self-regulation, so a key piece is developing self-regulation skills. To be successful, individuals with ADHD must have someone to help them co-regulate. The younger they are the more support they need, but that support needs to be continued right into early adulthood.”

In Summary

There are still gaps in diagnostic criteria, assessment, management strategies, and awareness regarding the long-range outcomes of ADHD. Looking ahead, a group of experts participating in the 2019 ADHD Public Health Summit, hosted by CHADD, recommend the following:³³

• Increase awareness of the lifelong health risks of ADHD among (parents/caregivers, mental health professionals, primary care providers, insurers and health payers, public health agencies)

• Develop policies and strategies to address long term health effects of a diagnosis

• Increase research and advocacy efforts to raise awareness and improve long term health outcomes

• Develop strategies to mitigate the risk of adverse health consequences

• Positive Behavior Support Plan (PBSP) – National Center for Pyramid Model Innovations (NCPMI) University of South Florida (a six-step guide to support positive behavior)

• Functional Behavior Assessment (FBA) – Iris Center Peabody College Vanderbilt University

• Executive Function Skills Testing – The Clay Center for Young Healthy Minds

• ADHD Public Health Summit (2019)

Back to Part 1 of this series on cultural and familiar perspectives on ADHD, and Part 2 on how adverse childhood experiences affect ADHD. Plus, when stimulants and potential misuse comes into play.