Background
Substance use disorder (SUD) is a complex condition that often coexists with other mental health disorders, making diagnosis and treatment more challenging. One condition that frequently goes unrecognized is Attention-Deficit/Hyperactivity Disorder (ADHD), a neurodevelopmental disorder that can persist into adulthood and influence impulsivity, decision-making, and behavioral regulation.
Among individuals undergoing rehabilitation for substance use, ADHD symptoms may be mistaken for the effects of addiction or withdrawal. Without appropriate screening, many patients may remain undiagnosed, potentially affecting treatment engagement, relapse risk, and long-term recovery outcomes.
Despite growing international evidence linking ADHD and substance use disorder, local data among Filipino adults receiving rehabilitation remain limited. This study sought to determine the prevalence of ADHD among adults with substance use disorder, validate a standardized diagnostic instrument for local use, and identify factors associated with ADHD to support more evidence-based rehabilitation strategies.
The Research Challenge
The research team sought to determine the prevalence of ADHD among adults admitted to government drug rehabilitation centers and examine whether selected sociodemographic and clinical characteristics were associated with the condition.
The study explored questions such as:
- How common is ADHD among adults receiving treatment for substance use disorder?
- Which demographic and clinical factors are associated with ADHD?
- Can a standardized ADHD assessment tool be reliably used within the local rehabilitation setting?
- How can early screening support more effective rehabilitation and treatment planning?
Beyond estimating prevalence, the project addressed a broader challenge frequently encountered in clinical research: ensuring that screening instruments are both reliable and appropriate for the population before they are used to generate evidence and guide healthcare decisions.
Data2Stats’ Role
Data2Stats provided comprehensive statistical support throughout the project, helping transform clinical and questionnaire data into reliable evidence for mental health and addiction research.
The team supported the study through:
- Research consultation and study design guidance;
- Sample size determination and verification;
- Data management, validation, and quality assurance;
- Pilot study analysis and diagnostic tool validation;
- Development of the statistical analysis plan;
- Statistical analysis and interpretation of findings;
- Preparation of publication-ready statistical tables;
- Statistical reporting support; and
- Technical review of the research manuscript.
By ensuring that the data were carefully managed and the diagnostic instrument was appropriately validated, the project produced findings that contribute to a better understanding of ADHD among adults undergoing substance use rehabilitation.
Statistical Methods Used
To address the research objectives, several statistical methods were employed.
Descriptive statistics were used to summarize participants’ sociodemographic and clinical characteristics and estimate the prevalence of ADHD.
The Diagnostic Interview for ADHD in Adults (DIVA-5) underwent local validation through Cohen’s Kappa and McNemar’s Test to assess agreement with psychiatrists’ diagnoses and evaluate the instrument’s reliability.
Chi-square tests were used to examine associations between ADHD and selected categorical variables, while Fisher’s Exact Test and Monte Carlo simulation were applied when statistical assumptions were not met. Cramer’s V was calculated to determine the strength of significant associations.
All statistical analyses were performed using R version 4.4.2, while Microsoft Excel was used to support participant randomization during the pilot study.
What the Data Revealed
The study found that approximately one-fourth of adults receiving treatment for substance use disorder met the criteria for ADHD, highlighting that coexisting ADHD is a considerable concern within rehabilitation settings.
The analysis further revealed that several clinical characteristics – including previous rehabilitation admissions, polysubstance use, and tobacco and cannabis use – were significantly associated with ADHD. In contrast, commonly examined sociodemographic characteristics such as age, sex, educational attainment, and employment status showed no significant associations.
Equally important, the study demonstrated that the DIVA-5 showed good agreement with psychiatrist diagnoses, providing evidence that it is a reliable instrument for identifying ADHD among adults with substance use disorder.
Together, these findings suggest that clinical history may provide more meaningful insights than demographic characteristics when identifying individuals who may benefit from further ADHD assessment.
A Valuable Lesson in Clinical Research
Mental health conditions often share overlapping symptoms, making accurate assessment essential for effective treatment planning.
This study highlights an important lesson in clinical research:
Reliable screening begins with a validated tool.
Before researchers can confidently estimate prevalence or identify associated factors, they must first establish that their assessment instrument performs consistently within the population being studied.
The study also demonstrates that meaningful associations are not always found where researchers initially expect them. While demographic characteristics showed little relationship with ADHD, several clinical factors emerged as more informative indicators.
These findings reinforce the importance of validating research instruments, relying on statistical evidence rather than assumptions, and using standardized screening to generate findings that can support evidence-based rehabilitation and mental health care.
Outcome and Impact
The project successfully generated local evidence on the prevalence of ADHD among adults receiving treatment for substance use disorder while identifying clinical factors associated with the condition.
More importantly, the study demonstrated the value of rigorous statistical support in helping researchers:
- Validate diagnostic instruments before implementation;
- Estimate disease prevalence with confidence;
- Identify clinically meaningful associations through appropriate statistical analyses;
- Interpret findings responsibly; and
- Translate research evidence into recommendations that support integrated mental health and rehabilitation services.
The findings also reinforce the importance of routine ADHD screening within substance use treatment programs, enabling healthcare providers to identify individuals who may benefit from further assessment and more comprehensive care.
Key Takeaways
- ADHD is relatively common among adults undergoing treatment for substance use disorder.
- Validating screening instruments is essential before using them in clinical research.
- Clinical characteristics may provide stronger indicators of ADHD than demographic factors.
- Appropriate statistical methods strengthen the credibility and reliability of prevalence and association studies.
- Early identification of coexisting ADHD can support more comprehensive rehabilitation planning and improve future mental health research.
At Data2Stats, we believe that statistical analysis is about more than estimating prevalence. It is about ensuring that research tools are reliable, findings are trustworthy, and evidence can be translated into meaningful insights that support better clinical decisions, stronger rehabilitation programs, and improved patient outcomes.
