Introduction
ADHD, or attention-deficit/hyperactivity disorder, is a prevalent neurodevelopmental condition that affects 2.5% of adults and 7.2% of children globally, according to epidemiological research.1, 2 The existence of pervasive, developmentally inappropriate, and damaging levels of impulsivity, hyperactivity, and inattentiveness is the basis for the diagnosis of ADHD.3. People with ADHD are more likely to experience a variety of negative outcomes if they are not treated, including emotional difficulties, self-harm, substance abuse, academic underachievement and expulsion from school, problems in relationships and the workplace, and criminal activity.4 For this reason, improving the long-term wellbeing of those who have ADHD requires prompt diagnosis and effective treatment. According to current guidelines, depending on the patient’s age, degree of impairment, and comorbidities, a combination of non-pharmacological (e.g., behavioural or cognitive therapy) and pharmaceutical treatment is frequently advised.5. Current information on the global trends and patterns of the use of ADHD drugs by income level and geographic area, with a broader range of nations covered and statistics on the more recently approved ADHD medications.
Findings
The findings demonstrated that, with notable regional variations, the consumption of ADHD medications grew globally by +9.72% (95% confidence interval [CI], +6.25%, +13.31%) each year, from 1.19 DDD/TID in 2015 to 1.43 DDD/TID in 2019. Increases in the use of ADHD medications were seen in high-income nations but not in middle-income countries when the countries’ income levels were stratified. The combined rates of ADHD drug use in 2019 were 0.37 DDD/TID (95% CI, 0.23, 0.58) in upper-middle-income countries, 0.02 DDD/TID (95% CI, 0.01, 0.05) in lower-middle-income countries, and 6.39 DDD/TID (95% CI, 4.63, 8.84) in high-income countries.
Interpretation
Most middle-income nations have lower rates of ADHD medication consumption and prevalence estimates than the global epidemiological prevalence of the condition. To reduce the possibility of unfavourable consequences from undiagnosed and untreated ADHD, it is crucial to assess the possible obstacles to diagnosis and treatment in these nations.
Evidence before this study
Using the following search terms (((Multinational) OR (Global)) AND ((Treatment) OR (medication)) AND ((attention deficit hyperactivity disorder) OR (ADHD) OR (hyperkinetic disorder)) AND ((Consumption) OR (Use) OR (Utilisation)) AND (Trend)), we searched PubMed for English-language articles published between January 1, 2001, and May 1, 2022. After excluding items based solely on their titles that we felt were irrelevant, the search yielded 62 entries. With varying study years and methodologies, four studies examined global trends in the use of ADHD medications in eleven nations, five western countries, the Nordic countries, and fourteen countries/regions.
Added value of this study
The current study evaluated the use of ADHD medications in 64 countries. We focused on data from middle-income nations where there is limited information available in the literature regarding the use of ADHD medications, as well as data on recently approved ADHD medications. Between 2015 and 2019, we found that the overall consumption of ADHD medications increased by +9.72% year in 64 countries; nevertheless, high-income nations, not middle-income countries, are the main drivers of this growth in drug consumption. The two ADHD drugs with the biggest worldwide growth over time were amphetamines and guanfacine.
Implications of all the available evidence
The huge disparity in the use of ADHD medications by national income levels should be addressed as soon as possible, considering the crippling effects of ADHD and the significance of early therapies to prevent serious outcomes like trauma and suicidality. More research on the safety and tolerability of newer ADHD medicines, like guanfacine and clonidine, is required in response to the growing trends in their use. Lastly, there is a pressing need to gather data in low-income nations because there is little to no information on the use of ADHD medication in these nations.
Methods
Data sources
The IQVIA-Multinational Integrated statistics Analysis System (MIDAS) database provided us with the international sales statistics for ADHD medications. In order to enable comparisons of national sales volume, MIDAS collects multinational data on sales volume of particular pharmaceutical items from various distribution channels (manufacturers, wholesalers, hospitals, and retail pharmacies) with international standards. 88% was stated to be the average nationwide coverage of MIDAS data.11, 14, 15, IQVIA conducted adjustments to estimate the total sales volume for countries where the MIDAS database did not have 100% market coverage. These adjustments were based on knowledge of the market share of participating wholesalers and retail or hospital pharmacies.16 The MIDAS database is a stand-in for external data sources when assessing pharmaceutical consumption across national borders. It has been verified against them.14, 18, 19, Similar to earlier research, we used sales data as a stand-in for each nation’s consumption. Since patient-level data is not included in the MIDAS database, institutional review board approval was not necessary and no patient demographic information was provided.
Data inclusion
The IQVIA-MIDAS database contains sales information for ADHD medications from 64 countries and regions between 2015 and 2019. The European Pharmaceutical Market Research Association (EphMRA) Anatomical Therapeutic Chemical (ATC) categorization codes were used to identify the ADHD medications used in this investigation, which included amphetamines, methylphenidate, atomoxetine, clonidine, and guanfacine (Table S1, Supplement pp2). “Amfetamine,” “dexamfetamine,” “metamfetamine,” and “lisdexamfetamine” were among the amphetamines. “Methylphenidate” and “dexmethylphenidate” were two examples of methylphenidate. Because of their alternative indications for illnesses other than ADHD, only medicines having ATC codes beginning with “N” for the nervous system (amphetamines, guanfacine, and clonidine) were included. The United Nations (UN) “Standard Country or Area Codes for Statistical Use” were used to divide the included countries/regions into the following areas based on their geographical locations: Oceania, Eastern Asia, South-eastern Asia, Southern Asia, Western Asia, Northern Africa, and Southern Africa.20
Statistical analysis
The primary end measure was the frequency of use of ADHD medication, which was measured as the defined daily dosage (DDD) divided by the daily total number of children and adolescents (DDD/TID). DDD, which was exclusively offered for single-molecule drugs, is the estimated daily maintenance dose (ADM) of a medication used for its primary indication. As a result, the ATC/DDD Index, created by the World Health Organization’s (WHO) Collaborating Centre for Drug Statistics Methodology, was used to map the drug ingredients of combination products from a standard unit (defined as a single tablet, capsule, ampoule/vial, or 5 mL oral suspension), formulation. (Table S1, Supplement pp2).24
