Prospective longitudinal multimodal study of adult attention deficit hyperactivity disorder in a transcultural cohort: clinical response, tolerability, and behavioral improvements
B. Fernández1, R. Dios2, J.M. Justo1
1ULSNE, Psychiatry, Bragança, Portugal, 2Hospital de Braga, Psychiatry, Braga, Portugal
Background: Adult Attention deficit hyperactivity disorder (ADHD) is frequently under-recognized and associated with academic, occupational, and social impairment. Psychiatric comorbidities—including anxiety, depression, and emotional dysregulation—complicate management and may mask core ADHD symptoms. Real-world longitudinal data on pharmacological efficacy, tolerability, and behavioral outcomes across diverse cultural populations remain scarce, particularly regarding high-risk behaviors such as hypersexuality or school dropout. We report preliminary results from a prospective, longitudinal, multimodal study of adults with ADHD managed via telemedicine in a private clinical setting.
Aims & Objectives: To evaluate the longitudinal effectiveness, tolerability, and behavioral outcomes of pharmacological treatment in adults with ADHD across diverse cultural contexts, including the impact and outcomes of late diagnosis of adhd, using a prospective, multimodal approach.
Method: This prospective, longitudinal, multimodal observational study was initiated in 2022. Adults diagnosed with ADHD were recruited from multiple regions (Portugal, Brasil, Spain, France, Colombia, Venezuela, Russia), forming a transcultural cohort.
Inclusion criteria required a confirmed ADHD diagnosis and consent to participate in longitudinal follow-up via teleconsultation in a private clinic.
Initial assessments included the DIVA-5 Scale to quantify baseline symptom severity.
Pharmacological interventions included lisdexamfetamine, methylphenidate extended-release (ER), methylphenidate immediate-release (IR), atomoxetine, clonidine and bupropion with individualized dosing and treatment switches as clinically indicated.
Comorbidities were managed prior to ADHD-specific treatment.
Inclusion criteria required a confirmed ADHD diagnosis and consent to participate in longitudinal follow-up via teleconsultation in a private clinic.
Initial assessments included the DIVA-5 Scale to quantify baseline symptom severity.
Pharmacological interventions included lisdexamfetamine, methylphenidate extended-release (ER), methylphenidate immediate-release (IR), atomoxetine, clonidine and bupropion with individualized dosing and treatment switches as clinically indicated.
Comorbidities were managed prior to ADHD-specific treatment.
Results: A total of 48 participants were included (57.8% male, n=28; 42.1% female, n=20), with a mean age of 33 ± 7.1 years. Educational background: 42.1% (n=20) held a university degree, 36.8% (n=14) completed secondary school. Academic impact included discontinuation of university due to ADHD symptoms in 20.8% (n=10) and academic impairment without discontinuation in 33.3% (n=16). Comorbidities included anxiety 50% (n=24), depression 29.2% (n=14), impulsivity 25% (n=12), personality disorders 12.5% (n=6), substance abuse 33% (n=16), pornography addiction 4.2% (n=2), and hypersexuality/high-risk behaviors 12.5% (n=6). ADHD subtypes included inattentive 75% (n=36), mixed 25% (n=12).
Baseline DIVA-5 scores indicated moderate-to-severe symptomatology.
After one month of pharmacotherapy, 70.6% (n=24/34) achieved full remission and 23.5% (n=8/34) partial remission (p<0.001 vs baseline). Ten percent (n=3/34) remained on low-dose lisdexamfetamine and eight (n=8/34) on methylphenidate ER. Non-responders to atomoxetine (n=2, all from Russia) transitioned to bupropion with subsequent mild improvement.
Mild adverse events occurred in 8.3% (n=4; tics on methylphenidate formulations).
All six patients with hypersexuality/high-risk behaviors showed marked behavioral improvement under stimulant therapy.
Baseline DIVA-5 scores indicated moderate-to-severe symptomatology.
After one month of pharmacotherapy, 70.6% (n=24/34) achieved full remission and 23.5% (n=8/34) partial remission (p<0.001 vs baseline). Ten percent (n=3/34) remained on low-dose lisdexamfetamine and eight (n=8/34) on methylphenidate ER. Non-responders to atomoxetine (n=2, all from Russia) transitioned to bupropion with subsequent mild improvement.
Mild adverse events occurred in 8.3% (n=4; tics on methylphenidate formulations).
All six patients with hypersexuality/high-risk behaviors showed marked behavioral improvement under stimulant therapy.
Discussion & Conclusions: Stimulant therapy with lisdexamfetamine and methylphenidate was associated with superior symptomatic and behavioral outcomes compared to atomoxetine, which showed lower efficacy, particularly in Russian participants lacking access to stimulants.
Presence of psychiatric comorbidities, substance use, and personality disorders was associated with poorer treatment response (p<0.05). This demonstrates that stimulant therapy is effective, well-tolerated, and leads to meaningful behavioral improvements, including reduction of hypersexuality and high-risk behaviors.
Findings support telemedicine-based longitudinal follow-up and highlight the importance of comorbidity management and individualized pharmacotherapy. Behavioral improvements in high-risk domains suggest broader clinical benefits beyond core ADHD symptoms.
These results provide novel, clinically relevant insights for adult ADHD management across diverse cultural contexts and underscore the need for future studies to identify predictors of response and optimize personalized treatment strategies.
Presence of psychiatric comorbidities, substance use, and personality disorders was associated with poorer treatment response (p<0.05). This demonstrates that stimulant therapy is effective, well-tolerated, and leads to meaningful behavioral improvements, including reduction of hypersexuality and high-risk behaviors.
Findings support telemedicine-based longitudinal follow-up and highlight the importance of comorbidity management and individualized pharmacotherapy. Behavioral improvements in high-risk domains suggest broader clinical benefits beyond core ADHD symptoms.
These results provide novel, clinically relevant insights for adult ADHD management across diverse cultural contexts and underscore the need for future studies to identify predictors of response and optimize personalized treatment strategies.
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