Evolución de menores diagnosticados con trastorno de déficit de atención e hiperactividad. Estudio de seguimiento en una muestra española

Background and Objectives

Attention-deficit/hyperactivity disorder (ADHD) has been considered a chronic condition with long-term associated risks. According to clinical practice guidelines, ADHD constitutes a chronic disease requiring continuous monitoring. Previous literature documents ADHD prevalence rates of 70% among adolescents and between 5% and 45.7% in adults, though these figures may be underestimated when using self-reports rather than informant-based assessments. Earlier studies have identified several factors predicting greater symptom persistence, including functional impairment or interference in daily life, combined-type ADHD presentation, comorbidity with intellectual disability, presence of psychosocial adversity factors, and parental psychopathology.

The literature establishes a distinguishable clinical evolution pattern: inattention symptoms tend to continue into adulthood (persisting in 94.9% of the population), while hyperactivity/impulsivity symptoms decline considerably (persisting in 34.6% of the population). Multiple previous studies have documented significant mental health disease risks in adulthood in persons who experienced ADHD in childhood, especially depressive disorders, personality disorders, and substance abuse. ADHD has also been linked with important social, academic, and occupational problems: academic dropout, behavioral disturbances, antisocial behaviors, less stable family situations, increased risk of substance use, illegal behaviors, and social relationship difficulties, particularly in adults with persistent symptomatology.

Within this context of clinical alarm regarding behavioral, conduct, and occupational implications of ADHD diagnosed in childhood, the present study proposes a more naturalistic approach through longitudinal follow-up of a sample of children diagnosed with ADHD in a real clinical setting. Two cohorts were selected to evaluate evolution variables at five years (2009 cohort) and ten years (2004 cohort) post-diagnostic detection, examining whether elapsed time influences symptomatic and functional presentation in patients.

Specific objectives were: (1) describe the clinical status of children diagnosed with ADHD at follow-up time; (2) analyze their primary occupation; and (3) understand difficulties and interference in daily life.

Method

Participants

The study was based on the WOMI database (Primary Care Clinical Records Viewer) in Oviedo, Asturias, Spain. Children were included if diagnosed in primary care pediatric services with code P21 (attention deficit/hyperactivity disorder) during 2004 and 2009 and who agreed to participate in a voluntary follow-up telephone interview. Diagnostic criteria employed followed the International Classification in Primary Care (ICPC), specifying: early-onset attention deficit or hyperactivity, marked lack of task continuity, and hyperactive behavior modulated across varied situations and over time.

Children diagnosed who were non-residents of the Oviedo health area (precluding longitudinal follow-up) and those not located for telephone interview were excluded. The final sample consisted of 95 clinical cases distributed across two cohorts: 42 children diagnosed in 2004 (44.21% of sample) and 53 diagnosed in 2009 (55.79% of sample). Of the 95 participants, 76 (80%) completed sex information, with 33 from the 2004 cohort (78.57%) and 43 from the 2009 cohort (81.13%) being male. Regarding interview respondent: 71 of 95 cases (74.74%) were direct patient interviews (19 of 42 in 2004 [45.24%] and 52 of 53 in 2009 [98.11%]), while in remaining cases (24 of 95 [25.26%]) parents were the informants.

Mean age at ADHD diagnosis was 7.76 years (median = 8.00; 95% CI = 6.64-8.88). At telephone interview time, mean age was 18.24 years in the 2004 cohort (median = 18.00; 95% CI = 17.07-19.41) and 16.49 years in the 2009 cohort (median = 15.00; 95% CI = 14.75-18.23).

Design

This is a descriptive and longitudinal follow-up study. The design consisted of retrospective-prospective follow-up of two cohorts at different evaluation points (five and ten years post-diagnosis). The study was approved by the Research Ethics Committee of the Principality of Asturias (study code 55/2014).

Data Collection Procedure

Voluntary telephone interviews were conducted directly with adult ADHD patients. For patients who were minors or not located, interviews were directed to their parents or guardians. Although not all participants responded to all questions, information was gathered regarding current clinical status, occupation, and ADHD symptoms evaluated using standardized instruments.

Measurement Instruments

Clinical and Occupational Status: Patients or their parents were asked about clinical status ("Do you receive any treatment or clinical consultation for any mental health difficulty at the present time?") and occupational status ("What is your current occupation?" or if studying, "What educational stage are you completing?") at interview time. Occupational data were classified into seven categories: five study categories per Spanish educational system (primary, secondary, pre-university, work program, and high school), employment, and no occupation. For those receiving mental health treatment, diagnosis was recorded from the clinical history.

SNAP-IV Scale (Swanson, Nolan and Pelham): This instrument evaluated current ADHD symptoms through eighteen questions: nine items assessing inattention symptoms and nine assessing hyperactivity/impulsivity symptoms. Each question was answered on a four-point Likert scale. Clinical cutoff scores were established at: 1.78 for the inattention subscale, 1.44 for the hyperactivity/impulsivity subscale, and 1.67 for the global ADHD scale. These cutoff points were taken from the clinical practice guideline on ADHD in children and adolescents. Importantly, SNAP-IV results were not comparable to Spanish non-clinical population norms, as no such norms are available.

Strengths and Difficulties Questionnaire (SDQ) - Spanish Version: Used to evaluate current difficulties and impairment. The SDQ impact supplement consists of five questions regarding: (1) existence of current difficulties, (2) severity level, and (3) vital areas in which they interfere (cohabitation, peer relationships, occupational or academic domain, leisure and free time). The instrument provides qualitative information about interference from difficulties across different functioning domains.

Data Analysis

Descriptive measures of centralization (mean, median) and dispersion (95% confidence interval) were used for quantitative variables, and frequency distributions (percentages, absolute numbers) for categorical variables. Pearson correlations were calculated to evaluate the relationship between ADHD symptoms and functional interference. For group comparisons, one-factor ANOVA tests and Fisher exact tests for categorical variables were used. Statistical analysis was performed using SPSS version 15.00.

Results

Clinical Status and Treatment

Regarding current clinical status and treatment, responses were obtained from 89 participants. Of 89 respondents: 60.7% (n = 54) received no treatment for mental health difficulties at follow-up time; 33.7% (n = 30) had psychopharmacological treatment prescribed; 4.5% (n = 4) received exclusively psychological treatment; and 1.1% (n = 1) received combined treatment (psychological and psychopharmacological).

Treatment distribution varied between cohorts. In the 2004 cohort (n = 40): 57.5% received no treatment, 32.5% received psychopharmacological, 7.5% received psychological, and 2.5% received combined treatment. In the 2009 cohort (n = 49): 63.3% received no treatment, 34.7% received psychopharmacological, 2.0% received psychological, and none received combined treatment.

Among 35 cases receiving any mental health treatment, 15 diagnoses were analyzed from clinical history: ADHD in 46.7% (n = 7), personality disorder in 26.70% (n = 4), unknown diagnosis in 13.20% (n = 2), anxiety disorder in 6.7% (n = 1), and ADHD comorbid with developmental disorder in 6.7% (n = 1).

Regarding stimulant treatment received during follow-up, 95.5% of the total baseline population (n = 134) received stimulant medication at some point. Those treated with stimulants appeared to have more current difficulties (determined with SDQ) than those not treated (χ² = 0.018, 1 df). Of the total baseline sample, 29.9% of participants were treated exclusively in primary care services, and those cases appeared to have fewer current difficulties than those treated through mental health services or neuropediatrics (χ² = 0.024, 1 df).

Occupation

Occupation at interview time showed distinct distributions between cohorts (n = 95). In the 2004 cohort (10-year follow-up): 41.7% were attending secondary school, 23.7% were attending pre-university, 18.8% were attending primary school, 10.5% were in a work program, 2.1% had employment, and 12.5% had no occupation. In the 2009 cohort (5-year follow-up): 28.9% were attending secondary school, 14.6% were in a work program, 13.2% were attending pre-university, 5.3% were attending primary school, 4.2% were pursuing university studies, 6.3% had employment, and 7.9% had no occupation.

Overall, 4.7% of the total sample (n = 95) had no occupation.

ADHD Symptoms - SNAP-IV

Responses to the SNAP-IV questionnaire were obtained from 71 participants. In the total sample, mean score on the inattention subscale was 1.3145 (95% CI = 1.153-1.475); on the hyperactivity/impulsivity subscale, 1.007 (95% CI = 0.820-1.193); and on the global ADHD scale, 1.161 (95% CI = 1.007-1.315).

Regarding participants above clinical cutoff scores: 31% of the total sample had clinically significant inattention symptoms; 32.4% had clinically significant hyperactivity/impulsivity symptoms; and 25.4% had clinically significant global ADHD symptoms. No statistically significant differences were found between cohorts in these proportions (inattention: Fisher 1 df = 0.292; hyperactivity/impulsivity: Fisher 1 df = 0.195; global scale: Fisher 1 df = 0.161).

However, statistically significant differences were found in mean scores of the global scale and inattention subscale between cohorts. Both were higher in the 5-year follow-up cohort (2009) compared to the 10-year cohort (2004). For the inattention subscale: 2004 cohort mean = 1.0819 (95% CI = 0.8248-1.3389) vs. 2009 cohort mean = 1.4573 (95% CI = 1.2556-1.6590; p = 0.023). For the global ADHD scale: 2004 cohort mean = 0.9404 (95% CI = 0.7092-1.1715) vs. 2009 cohort mean = 1.2961 (95% CI = 1.0954-1.4968; p = 0.024). For the hyperactivity/impulsivity subscale, the difference approached statistical significance (2004 cohort mean = 0.7852 vs. 2009 cohort mean = 1.1423; p = 0.063).

Statistically significant differences were found in global ADHD scale scores according to who completed the questionnaire. More cases exceeded clinical cutoff scores on the global ADHD scale when SNAP-IV was answered by parents than when answered directly by the patient (Fisher 1 df = 0.042). Mean scores for the inattention subscale were: direct patient mean = 0.9895 (95% CI = 0.7383-1.2408) vs. parents mean = 1.4604 (95% CI = 1.2653-1.6555). For the global ADHD scale: direct patient mean = 0.9323 (95% CI = 0.6980-1.1666) vs. parents mean = 1.2635 (95% CI = 1.0681-1.4588; p = 0.047).

Difficulties and Impairment - SDQ

Responses to the SDQ impact supplement were obtained from 70 participants. Regarding perception of improvement since initial consultation: 88.9% of the 2004 cohort reported being better ("somewhat better" or "much better") since first clinic visit; in the 2009 cohort, 88.4% reported being better.

Regarding current difficulties: 66.2% (n = 46) reported continuing to have difficulties in one or more areas (emotions, concentration, behavior, or ability to relate with others), with no significant differences between cohorts (Fisher 1 df = 0.609). Of those with current difficulties, 95.7% reported these causing interference in one or several areas of daily life.

The pattern of interference in specific areas (2004 cohort, n = 27; 2009 cohort, n = 43) showed:

Living with people: 2004: 14.8% (none), 11.6% (only a little), 11.6% (medium), 61.5% (much); 2009: 2.3% (none), 11.1% (only a little), 20.9% (medium), 65.1% (much).
Friends: 2004: 7.4% (none), 14.0% (only a little), 7.4% (medium), 71.2% (much); 2009: 2.3% (none), 11.1% (only a little), 20.9% (medium), 65.8% (much).
Work/study: 2004: 3.7% (none), 11.1% (only a little), 44.2% (medium), 41.0% (much); 2009: 9.3% (none), 14.0% (only a little), 20.9% (medium), 55.8% (much).
Leisure activities: 2004: 0% (none), 14.8% (only a little), 25.9% (medium), 59.3% (much); 2009: 7.0% (none), 14.8% (only a little), 20.9% (medium), 57.3% (much).

Correlation Between Symptoms and Interference

A positive and statistically significant correlation was found between current interference (evaluated with SDQ) and higher ADHD symptom indices (identified with SNAP-IV), regardless of cohort:

Interference vs. inattention subset: Pearson r = 0.393 (p = 0.01)
Interference vs. hyperactivity/impulsivity subset: Pearson r = 0.356 (p = 0.002)
Interference vs. global ADHD: Pearson r = 0.420 (p = 0.000)

Discussion and Conclusions

Perspective on ADHD Chronicity

The study questions the chronicity framework dominant in previous ADHD literature. Although clinical practice guidelines and most studies propose ADHD as a chronic condition with long-term associated risks, the present work documents a descending symptom pattern as time elapsed from diagnosis increases. Data revealed that both inattention and hyperactivity/impulsivity symptoms, as well as the global ADHD scale, were higher in the cohort with shorter follow-up duration (5 years in 2009) compared to the longer follow-up cohort (10 years in 2004). Additionally, descending rates were observed in the number of clinically significant cases for inattention, hyperactivity/impulsivity, and global ADHD scale, regardless of evaluated cohort.

These findings align with previous research that also questions ADHD absolute chronicity, showing decreasing prevalence rates as individuals age. However, it is important to underscore that although symptoms decline, they persist in a notable proportion: 25.4% of the sample maintained global ADHD symptoms above clinical cutoff at follow-up time.

Pattern of Symptomatic Evolution

Results support previous studies describing a differentiated evolution pattern for ADHD symptoms by subtype. As documented in literature, inattention symptoms tend to persist more than hyperactivity/impulsivity symptoms. In the present study, although both dimensions showed descending trends, the inattention subscale presented consistently higher mean scores, suggesting greater persistence of these symptoms.

Risk of Mental Disorders in Adulthood

Contrary to previous literature predictions emphasizing greater mental health disorder risk in adults with childhood ADHD histories, the present study found that 60.7% of the sample received no treatment for any psychological disorder after five to ten years from initial diagnosis. Although 33.7% received psychopharmacological treatment, recorded diagnoses did not confirm alarming rates of severe comorbidities. Among treated individuals, persistent ADHD represented 47% of diagnoses, followed by personality disorder (26.70%), anxiety disorder (6.7%), and other diagnoses (13.20% unknown; 6.7% ADHD comorbid with developmental disorder).

This pattern suggests that while some individuals maintain significant symptomatology, the sample overall does not present the expected rates of depressive disorders, serious personality disorders, or substance abuse that previous literature has documented in other ADHD childhood populations.

Discrepancies in Symptom Reporting

A particularly interesting finding was the discrepancy between informants. When SNAP-IV was completed by parents, scores were significantly higher than when completed directly by adult patients. This replicated a pattern documented in previous studies, where family informant reports tend to yield higher symptom rates than self-reports. Previous literature has interpreted this as evidence of ADHD underdiagnosis in adults through self-reports. However, the authors suggest an alternative interpretation: what constitutes a behavioral problem for a family member may represent a normal adaptive pattern for the adult individual. This interpretation aligns with the concept of cultural "psychopathologization" of childhood, where social norms and cultural expectations shape what is considered problematic.

Occupation and Academic Performance

Previous literature has documented alarming rates of academic dropout and failure in individuals diagnosed with ADHD in childhood. Results of the present study provide a less pessimistic perspective. Although the study did not explicitly evaluate academic or occupational success, most interviewees reported academic or occupational responsibility five to ten years after diagnosis. Only 4.7% of the sample reported having no occupation. In the longer follow-up cohort (10 years, 2004), the majority were attending secondary or pre-university education, while in the shorter follow-up cohort (5 years, 2009), greater occupational diversification was observed including university studies. These data question the alarm about academic failure that has characterized ADHD narratives in childhood.

Current Difficulties and Functional Interference

Two-thirds of the sample (66.2%) reported current difficulties in one or more areas (emotions, concentration, behavior, interpersonal relationships). However, the severity of these difficulties cannot be definitively evaluated since no Spanish non-clinical population norms exist for comparison. Of those reporting difficulties, 95.7% also reported interference in daily life areas, including cohabitation, friendships, academic/occupational performance, and leisure activities. Consistent with previous studies, a relationship existed between ADHD symptom intensity (measured with SNAP-IV) and functional interference (measured with SDQ).

Interestingly, cases treated with psychostimulant medications as well as those treated by specialized mental health professionals (neuropediatricians or mental health professionals) presented more current difficulties than those treated exclusively in primary care. The authors cautiously avoid attributing causality, noting that these results likely reflect a "reverse causality" phenomenon: cases with greater baseline difficulties were referred to specialized care or treated with stimulants, and these same cases probably maintain greater difficulties at follow-up.

Maturational and Contextual Factors

The authors propose that symptom diminishment with age may reflect the importance of maturational and contextual factors. ADHD could constitute a significant problem for childhood social and cultural dynamics, where children are expected to maintain sustained attention, inhibit impulses, and regulate movement. However, in adult contexts, the same behavioral patterns could represent normal adaptive variations or, at least, less problematic ones. This interpretation suggests ADHD is not solely an individual disorder but is partially constructed by specific environmental and cultural demands of childhood. The persistence of certain difficulties in adulthood could be understood as learned self-regulation skill deficits rather than symptoms of an immutable chronic disease.

Study Limitations

The authors identify several important limitations. First, ADHD cases derive from a real clinical practice sample without unified diagnostic procedure, representing a significant difference from most previous ADHD studies conducted in highly controlled academic settings. Second, the investigation was conducted in a specific cultural and healthcare context (Asturias, Spain), and different contexts may affect results. Third, cohorts were not temporally equivalent: one evaluated a 5-year period and the other a 10-year period.

Final Conclusions

Summarizing main findings, the study proposes a less alarming perspective regarding the clinical and academic course of individuals diagnosed with ADHD in childhood, in contrast to the dominant framework characterizing ADHD as a chronic condition inexorably linked to poor adult outcomes. Although proposing ADHD as chronic disease has justified intensive pharmacological interventions from symptom onset, data from the present work suggest that symptoms tend to diminish as individuals age, and that the majority does not develop serious mental health comorbidities nor experiences occupational or academic failure. The data provide a new conceptual framework for clinicians and families, who are principal decision-makers regarding ADHD treatment and how to implement it.

Importance and Contribution

This study makes significant contributions to the body of knowledge about natural evolution of ADHD diagnosed in childhood by providing follow-up data in a naturalistic clinical context. Its importance lies in several aspects:

Population Perspective: Unlike many academically controlled studies, it uses real clinical practice data from primary care, increasing ecological validity of findings.
Questioning Chronicity: Provides empirical data questioning the dominant paradigm that ADHD is an immutable chronic disease, instead showing a pattern of descending symptomatic evolution.
Culturally Informed Perspective: The study integrates a critique of the cultural context of childhood medicalization, proposing that part of what is considered "ADHD" may be cultural construction rather than intrinsic pathology.
Clinical Impact: Results have direct implications for clinical decision-making, particularly regarding stimulant medication prescription, suggesting that a less alarmist perspective may be more appropriate.
Occupation Data: Contributes evidence contradicting pessimistic predictions of academic and occupational failure, showing that the majority of individuals with childhood ADHD histories achieve academic or occupational responsibilities.