Acknowledgement of ADHD reaches back to 1775 in medical literature (Faraone et al., 2021). Nevertheless, there has been debate over the years regarding its classification system. As a result of the discrepancies, the diagnostic criteria have undergone revisions multiple times. Updates in the DSM manual for the diagnostic criteria for ADHD reflect all the improvements and advancements regarding understanding this disorder.

The diagnostic value of ADHD first took place in 1968 when it was named as the “Hyperkinetic Reaction of Childhood in DSM-II (American Psychiatric Association, 1968). As per symptoms of the disorder, hyperactivity, short attention span, restlessness, and distractibility were included in the criteria, much as they are in the current description of ADHD (Barkley, 2011). In 1980, the focus on the symptoms shifted from hyperactivity to inattention. ADHD gained popularity as inattention was discovered to be another symptom. DSM-III (American Psychiatic Association, 1980) reclassified ADHD under two divisions: ADD with hyperactivity and ADD without hyperactivity. In 1987, hyperactivity was reintroduced as a core symptom in the revised version of DSM (DSM III-R) (American Psychiatric Association, 1987). DSM III-R defined the disorder with the symptoms (inattention, hyperactivity and combined) all together without any subtypes. Additionally, ADHD was titled as Disruptive Behavior Disorder (DBD). Later in 1994, DSM-IV (American Psychiatric Association, 1994) brought back the subtypes as predominantly inattentive, predominantly hyperactive and combined. This version slightly broadened the definition of ADHD by incorporating instances related to social, vocational, and academic settings in the diagnostic criteria, implying that ADHD was accepted to be not just a disorder affecting children. The revised version of DSM-IV (DSM-IV-R) (American Psychiatric Association, 2000) was later released in 2000 and a fourth sub-category named “not otherwise specified” was added. The impairment had to be present before the age of 7.

DSM-5 was published by the American Psychiatric Association in May 2013 (Steinau, 2013; Surís et al., 2016). DSM-5 is the latest edition of the DSM and replaces the DSM- IV-TR published in 2000. Although new disorders were generally included in DSM-5, some changes were made such as changing the diagnostic criteria of some existing disorders (American Psychiatric Association, 2013; Kendler, 1017). As the latest updated version of the DSM, DSM-5 criteria require that symptoms exacerbate or degrade the quality of social, vocational, and intellectual functioning and affect two or more areas of daily functioning to diagnose an individual (American Psychiatric Association, 2013). Clinically, ADHD involves three presentations: inattention (ADHD-I), hyperactive/impulsive (ADHD-HI) and combined (ADHD-C). Inattention presentation includes the inability to pay or sustain attention, impaired thinking, inability to finish tasks, disorganized, distracted easily, and forgetfulness. The hyperactive/impulsive presentation includes the following symptoms: fidgeting, excessive talking, frequently interrupting, excessive physical activity, and inability to wait or take turns. Individuals who exhibit both inattention and hyperactivity/impulsivity symptoms are classified under the ADHD combined presentation (Rigler et al., 2016). In the previous versions, these presentations were referred to as “subtypes.” However, this terminology has been updated as “presentations” in DSM-5 in order to reflect that the symptoms are not stable and may change over time (Epstein and Loren, 2013; Leffa et al., 2022).

Considering all the developments in the history of ADHD, the DSM-5 was issued in 2013 with significant changes in the criteria. ADHD has become recognized as a neurodevelopmental condition rather than Disruptive Behavior Disorder in the DSM-5. ADHD symptoms are classified as severe, moderate, or mild, with more flexibility regarding the absence or presence of symptoms in social, occupational or academic settings (Steinau, 2013; Surís et al., 2016). While symptom changes may be observed due to maturity, the DSM-5 notes that problems with hyperactivity, poor attention and impulse control persist and that many young individuals with ADHD persist substantially impaired even throughout adulthood. According to the symptomology presentation indicated by DSM-5, the criteria suggest that the individual should be experiencing (1) inattention or (2) hyperactivity and impulsivity or both patterns together for at least before the age of 12 without any psychotic disorder background. These symptoms must be present in two or more settings (social, academic and occupational life), resulting in impairment (American Psychiatric Association, 2013).

Some of the changes in the DSM have caused concerns from a clinical point of view. These changes have paved the way for adult diagnosis (Young and Goodman, 2016). For ADHD diagnosis in adults, DSM-IV required the presence of at least six symptoms, while DSM-5 reduced that criterion to five for adults (Maltezos et al., 2020). The reduction of the ADHD cut-off points in DSM-5 compared to DSM-IV has increased the likelihood of receiving the diagnosis of ADHD. Nevertheless, both versions include 18 items in total, the first nine items are related to inattention and the other nine items address hyperactivity and impulsivity symptoms. However, unlike DSM-IV, the ADHD criteria of DSM- 5 are no longer only for children. On one hand, this may be recognized as an ethical problem because the cut-off scores for the diagnostic criteria have been reduced. On the other hand, it has enabled many people to receive the diagnosis, access the adequate intervention and thereby improve their quality of life. Thus, the changes to the DSM-5 criteria for ADHD more accurately reflect the current scientific understanding of the disorder and help to better capture the diversity of symptoms and impairments experienced by individuals with ADHD.

While the DSM-5 introduced several changes, it is still recommended to consider factors such as age of onset and areas affected by symptoms (Rigler et al., 2016). Age of onset of ADHD is one of the most discussed concepts in the DSM. Debate over whether ADHD is an early age-onset or “late-onset” is still being debated (Caye et al., 2017; Cooper et al., 2018). The concept of late-onset does not emphasize the later onset of the disease, but the manifestation of the symptoms later in life. Some individuals with ADHD may compensate the cognitive and behavioral impairments by developing coping strategies in childhood or it could be masked or misdiagnosed by other conditions such as anxiety or depression (Riglin et al., 2022; Onandia-Hinchado et al., 2021). In such cases, not only clinical presentation but also socioeconomic and cultural differences are of great importance.

The previous versions of DSM involved statements oriented to children and adolescents. However, DSM-5 contains more general statements relevant to all age groups. For instance, in the DSM-IV, the statement “often loses things necessary for task activities” applied to toys, school-related activities or items. In DSM-5, these examples were expanded to items which also apply to adults (e.g., wallets, paperwork, keys). Compared to DSM-IV, DSM-5 has allowed the diagnostic utility for adult screening to some extent. In the previous version of DSM, while the diagnostic criterion age was seven, this was increased to 12 in DSM-5. While for those younger than 17 years of age six symptoms from either domain is considered sufficient, for those older than 17 years of age, this criterion is reduced to five. Hence, the change in age of onset is also one of the factors that facilitates the diagnosis of adults (Posner et al., 2020).

Diagnosing ADHD requires a comprehensive assessment that considers both functional and cognitive impairments. It is essential to consider how ADHD affects an individual’s daily life across multiple areas, including academic performance, social relationships, and occupational functioning, rather than focusing solely on meeting the diagnostic criteria (Posner et al., 2020). Cognitive impairments, on the other hand, are important for predicting functional outcomes, understanding symptom presentation and differential diagnosis. Assessing the both of these impairments enables clinicians to develop tailored interventions and pinpoint the specific areas that require special attention.

Clinical interviews conducted by healthcare professionals have been the most acknowledged means of screening to establish an appropriate diagnosis (Danielson et al., 2018). It is substantial to determine the severity, duration, outcomes, genetic predispositions and the potential existence of any co-occurring conditions and ensure that the symptoms match the criteria and do not belong to another disorder. Apart from interviews, clinical experts often conduct multiple methods such as neuropsychological and behavioral assessment tools as well as gathering information from other informants involved in the patient’s life (NICE, 2018; Hall et al., 2016). However, to ensure interview quality, clinical interviews should be conducted first followed by secondary screening tools.

Clinical interviews have always been of greater clinical value than neuropsychological testing, computerized tests, standardized questionnaires and other tools (Hall et al., 2016). They are divided as structured and unstructured. Structured interviews are objective with strictly predefined questions. Unstructured interviews are performed with a sequence of questions asked by the interviewer that are unpremeditated and adjusted based on the course of the session (Marshall et al., 2021). Although they may help the interviewer discover different aspects and the needs of the patient and build comprehensive rapport, they are low in reliability, more subjective and depend on the expertise level of the interviewer. Consequently, structured interviews provide a systematic and standardized framework for clinicians. These interviews help the clinicians obtain the information that rating scales may not uncover, as structured interviews assess the presence of disorders and comorbidities.

A model based on the DSM has been proposed by a previous study, suggesting a 5-point model to facilitate a more accurate assessment within the diagnostic system, consequently enhancing clinical utility (Chang et al., 2016). Firstly, it is argued that assessing how mental health disorders are initially conceptualized is crucial for determining their clinical utility. Secondly, there is emphasis on the importance of the accurate communication of the relevant clinical information from the relevant parties (e.g., patient and patient’s family, practitioners, healthcare professionals). Thirdly, it is reported that the diagnostic criteria should always be used in the clinical interview. Lastly, the right interventions for the patient should be identified, and the patient should be guided adequately considering their current and future needs. Similarly, there are other important aspects in a clinical interview (Barkley, 2011). To obtain a diagnosis of ADHD, firstly, the patient who comes to the consultation must be questioned about any experienced symptoms in childhood and present symptom complaints. Further approach for establishing a diagnosis could be taken by conducting a formal interview with someone close to the patient (e.g., a family member, friend, teacher or partner) to further gain information about their daily functioning and social relationships in addition to behavioral observation, academic or medical reports (Posner et al., 2020). However, the interviewer is also an important determinant for the quality and the variety of the screening. Objective measurement and additional screening tools such as rating scales, computerized tests and many other tools that may support the accuracy of the diagnosis are of great importance (Hall et al., 2016).

In addition to clinical diagnosis, rating scales have a very important part in diagnosis of ADHD. Rating scales help the clinician to validate the presence of the disorder and to identify possible co-existing conditions. In addition, availability of multiple respondents in some rating scales allows the clinician to evaluate the patient profile with the responses of various people (e.g., family members, teachers). They are also a useful tool that allow the clinician to choose the most suitable treatment approach.

Rating scales are often the most favored evaluation tool after clinical interviews. Although they are secondary, they play a crucial role in addressing the limitations of clinical interviews. In clinical interviews, if the patient is young, the primary interviewee is usually a parent or guardian, although the patient is still interviewed. Conversely, the parents may provide broad perspective, however their impartiality should be considered. Similarly, children’s limited ability to express themselves emotionally and verbally may influence the clinician’s judgment. And in adolescents, they may also exhibit inconsistencies in self-report or deny experiencing problems. This situation highlights the importance of using rating scales with informants as a secondary diagnostic tool in the assessment of ADHD.

From a clinical standpoint, numerous approaches have been developed to evaluate the quality and usefulness of a tool, and several models have been proposed for it. Numerous factors are reported in the literature to be associated with clinical utility (Smart, 2006). These are usually related to many factors such as duration, accessibility, assessment, and the pricing of the tools. According to a previously suggested model, there are six elements to determine clinical utility of the rating scales. These are as follows respectively: (a) ease of use, (b) time, (c) training and qualifications, (d) format, (e) interpretation, and (f) meaning and relevance of information obtained. In general, the criteria considered here are the availability of the tool, its price, the clarity of the language of the instructions given for both the clinician and the patient, the time given and the effect of this time on reliability and validity, the acceptability of the tool for both the patient and the clinician, the expertise of the clinician and the requirements for interpreting the results, and many other minor criteria are encompassed in these six elements. Similarly, a multi-dimensional model indicates that there are four main elements to determine clinical utility: appropriateness, accessibility, practicability, and the acceptability (Smart, 2006). With these four elements, several important factors such as the appropriateness of the tool in general, its clinical significance, price, accessibility, whether it would cause ethical, legal, social or psychological concerns.

Rating scales are valuable in diagnosis and management, having been rigorously evaluated using psychometric indices such as SN, SP predictive power, and area under the curve (AUC) (Conners, 1999). SN is defined as the capacity of a test to detect patients who have illness/disorder which could be thought as percentage of the cases. SP shows how well the test can distinguish between different groups (e.g., ADHD vs. non-ADHD). In addition, AUC is also important in determining the quality of the diagnostic test. AUC value between 0.90 and 1.00 is considered as above excellent, between 0.80 and 0.90 as good, between 0.70 and 0.80 as fair, between 0.60 and 0.70 as poor, and between 0.50 and 0.60 as unsuccessful (Florkowski, 2008).

Use of rating scales involve both advantages and drawbacks. One possible advantage of rating scales is that they are uncomplicated and inexpensive to administer compared to clinical and neuropsychological testing tools. They could be applied in a variety of settings. They aid in screening and diagnosis procedure, the identification and measurement of the target symptoms and behaviors, treatment outcome, the frequency and severity of ADHD symptoms (Krieger and Amador-Campos, 2018). Similarly, rating scales are quick to administer and economically convenient (Rogers et al., 2022) although, they do not provide an elaborative diagnostic value as clinical interviews do. However, one of the issues with the standardized measures is that many studies focus on assessing ADHD by only utilizing rating scales based on threshold values to diagnose patients instead of using gold-standard clinical interviews (Mulraney et al., 2021). Compared to clinical interviews, rating scales are limited in terms of the variety of statement. Due to that, limiting the diagnosis to rating scales only could lead to misdiagnosis. In some cases, rating scales are more efficient at covering symptoms or potential problems than clinical interview tools except it is often achieved in less profundity. This is because rating scales do not always include information about the onset of the disorder, the duration of its existence or the relevant factors that may be contributing to the symptoms. Additionally, respondent bias in rating scales also may be involved (Döpfner et al., 2006).

Although the psychometric properties of a rating scale may be good, it is still a limited tool compared to clinical interviews. In general, rating scales should be considered secondary and used when significant suspicion of ADHD is present due to their limited ability to identify accurately (Chamberlain et al., 2021). Nevertheless, understanding an individual’s specific behavioral and EF challenges in everyday settings identified through rating scales could help clinicians tailor interventions to address those needs directly (Krieger and Amador-Campos, 2018).

Up to this date, neuropsychological tests have been widely used to demonstrate EF deficits in ADHD. ADHD is linked to impairments in multiple cognitive domains, with notable deficits in EF such as behavioral inhibition, working memory, set-shifting, planning, and organization. These impairments may vary based on task context, with greater challenges observed during monotonous or lengthy activities compared to engaging ones.

Neuropsychological tests can help to identify specific areas of impairment in EF. A systematic review and meta-analysis has demonstrated that Children with ADHD exhibited larger delays in attention, response inhibition, planning, and working memory compared to children with tic disorders (TD) and specific learning disorders (SLD)s (Sadozai et al., 2024). However, while these measures aim to evaluate discrete EF domains, considerable overlap in the neurobiology underlying these domains challenges their functional independence. For example, the Wisconsin Card Sorting Test (WCST), typically used to assess set-shifting, may also depend on working memory processes (Sadozai et al., 2024).

Assessment tools for EF in ADHD typically fall into two categories: subjective and objective measures. Subjective tools include clinical psychiatric interviews and rating scales or questionnaires, often relying on reports from the individual or informants familiar with their childhood behaviors. Objective tools, on the other hand, involve neuropsychological tests and Continuous Performance Tests (CPTs), providing standardized and quantifiable data (Posner et al., 2020). Some of the commonly employed neuropsychological tools are provided in Table 3:

These widely utilized tests tests (see Table 3) assess different aspects of cognitive functioning such as attention, memory, inhibition and cognitive flexibility. The Go/No-Go task has high SN (96.7%) and SP (83.3%) for discriminating ADHD from healthy controls. Variability in other on tests such as the Stroop or WCST is often influenced by ADHD presentation, age and other individual factors. This may limit their generalizability across different presentations of ADHD. As a result, the effectiveness of the tests in the diagnosis of ADHD may be variable and they may not always reflect the complexity of the cognitive profile of ADHD.

One important limitation is that ADHD encompasses a range of cognitive profiles, with some individuals exhibiting deficits in EF, while others show difficulties in non-executive processes like memory, temporal processing, and motivation regulation (Barkley, 2025). Conversely, although EF impairments within the clinical presentation of ADHD have been widely implicated, it is critical to recognize that there may be individual variability in the levels of cognitive performance deficits. Recent systematic review has revealed that several studies support this variability; some studies report minimal EF differences in ADHD patients compared to controls, while others emphasize significant differences which could be due to the discrepancies between methods used (self-report and objective measures) for measuring EF (Onandia-Hinchado et al., 2021). This contrast underlines the complexity of diagnosing and assessing EF impairments in ADHD, as both subjective and objective measures can provide valuable but different perspectives. Additionally, it is essential to acknowledge the heterogeneous nature of ADHD. Cognitive impairments and their neurophysiological correlates may vary with age and the presence of comorbid disorders. Some struggle in many areas, while others have very specific problems and function well in other areas (Posner et al., 2020). This also highlights the need for further research to explore how the sensitivity of neuropsychological measures such as the N-Back or Go/No-Go task may vary in different ADHD subgroups (Breitling-Ziegler et al., 2020). Notably, neuropsychological tests alone are not sufficient to diagnose ADHD. A diagnosis should be made by a qualified professional using a multifaceted approach that incorporates various sources of information (Krieger and Amador-Campos, 2021).

Continuous Performance Tests (CPTs) are one of the complementary screening methods that are involved in the diagnosis of ADHD. The purpose of the CPTs overall is to measure attention, vigilance, and inhibition. To measure these functions, there are two types of stimuli involved in the test. These are referred as target and non-target stimuli. Participants are assigned a target at the beginning of the test. This target may be a specific symbol or any stimuli and the scoring is performed by using omission and commission errors. The scoring would be done through omission and commission errors. Comission errors refer to pressing the button for a symbol other than the target and omission errors occurs when the target is missed (Sparrow, 2010). Through these values, certain functions such as attention, vigilance, inhibition and working memory could be measured (Harpin et al., 2016).

A recent systematic review and meta-analysis reviewed 74 studies using various neuropsychological measures, with most focusing on CPTs to evaluate attention, impulsivity, and response time variability. As seen in most CPT measurements, the CPTs analyzed commonly tracked variables such as omission errors (indicating inattention), commission errors (impulsivity), and reaction time variability. The SN of these tests varied widely, from 22 to 100%, with SP also ranging between 22 and 100%. The AUC values ranged from 0.59 to 0.93, showing the mixed performance of these tools (Peterson et al., 2024).

Just as any other tool, CPTs come with some limitations. One of these limitations particularly embodies validity and reliability issues. These tools, although being practical, may lack reliability due to technical factors, such as issues with the software or hardware used during administration (Roebuck-Spencer et al., 2017). Some CPTs can be financially burdening as they often require specialized equipment, and training. Additionally, CPTs measure limited abilities or only a sample of behavior under a controlled environment. And the CPT results of an individual may still not be reproducible in the same contexts due to several other uncontrollable factors such as motivation, attention or the type of existing disorder. Hence, the CPT results may not necessarily reflect the ADHD symptoms or may be influenced by other factors which are not directly related to the disorder. These factors could also introduce false positives that are either reporter or context-dependent which also indicates the importance of using appropriate normative data to ensure reliable interpretation (Rabin et al., 2014). Additionally, the application of multiple tasks may be particularly challenging for individuals with ADHD, who may have difficulty maintaining focus and remaining still for long periods of time (Breitling-Ziegler et al., 2020). Additionally, CPT’s ability to identify a wide range of deficits may be limited, as most of them are sensitive to identify specific types of functions such as attention and inhibition (Onandia-Hinchado et al., 2021). Collectively, these limitations highlight the importance of the clinical utility of these tools, as illustrated in Table 4 through SN and SN values of some of the most employed CPTs in ADHD:

MOXO, TOVA, QbTest, Conners CPT-3 and IVA-2 show varying psychometric utility (see Table 4) based on meta-analyses and experimental studies. In particular, the MOXO and TOVA show high SE (82 and 77%, respectively) and SP (87 and 77%), indicating that they are reliable in assessing ADHD-related symptoms such as attention, impulsivity and hyperactivity. But these findings are based on pooled data, which may not always reflect the diversity of real-world clinical settings. The QbTest provides significant utility in some subscales, however SN and SP vary across its subscales. Conners CPT-3, despite its high SP (≥90%), has a low SN (19–41%), suggesting that it may be more useful in ruling out ADHD diagnosis. The IVA-2 provides valuable insight into both visual and auditory attention, although its moderate SN and SP (75 and 68%) may limit its role in screening.

CPTs could be recommended to be used as a complementary tool, such as for monitoring treatment progress or as part of the diagnostic process alongside rating scales or previous medical and academic reports, can strengthen the evaluation process. For instance, QbTest have shown that attention measure of the QbTest is linked to overall impairment profile in ADHD and demonstrates sensitivity to the effects of ADHD medication (Emser et al., 2018). Finally, the applicability of CPTs for individuals with mental health challenges or disabilities requires further investigation to determine its effectiveness across diverse populations (Lancaster et al., 2009).

CPTs can be a useful tool for evaluating EF in ADHD (Park et al., 2019) when interpreted with caution, and the clinical utility of these tools is carefully considered. Besides, they may fail to represent the full EF profile since these tests are conducted in structured environment (Krieger and Amador-Campos, 2018). It is fundamental to emphasize that EF impairments are not exclusive to ADHD and may also occur in other disorders. While the CPT is effective in identifying cognitive differences between healthy individuals and those with ADHD, it may not be as reliable for distinguishing ADHD from other psychopathologies. While CPTs are useful for identifying cognitive deficits in ADHD, their variability suggests that they should be combined with other diagnostic methods, as they alone should not be used as a diagnostic tool (Peterson et al., 2024; Arrondo et al., 2024). CPTs could be recommended to be used as a complementary tool, such as for monitoring treatment progress or as part of the diagnostic process alongside rating scales or previous medical and academic reports, can strengthen the evaluation process. For instance, QbTest have shown that attention measure of the QbTest is linked to overall impairment profile in ADHD and demonstrates sensitivity to the effects of ADHD medication (Emser et al., 2018). Finally, the applicability of CPTs for individuals with mental health challenges or disabilities requires further investigation to determine its effectiveness across diverse populations (Lancaster et al., 2009).

In summary, both neuropsychological tests and CPTs are widely used and acknowledged in the ADHD assessment. Nevertheeless, there are important differences in ADHD presentation between children, adolescents and adults in terms of symptom expression, which requires different diagnostic measure considerations. In children, as hyperactivity is more overt and observable, with objective CPT measures like movement patterns and reaction times may be very effective for assessing hyperactivity. In contrast, hyperactivity presentation in adults implies more internal restlessness rather than a noticeable behavior. Hence, for adult assessment, rating scales may be more ideal and relevant (Emser et al., 2018). More so, ADHD encompasses a range of impairments with different intensities due to its heterogeneous nature. Some individuals may exhibit severe deficits in EF, while others show difficulties in non-executive processes like memory, temporal processing, and motivation regulation (Faraone et al., 2015). These findings not only contradict the notion that executive dysfunction is a core feature, but also may attention regarding the accuracy of tests focusing solely on cognitive measures.

One of the most discussed problems with the DSM is the age of onset of ADHD. It has been widely discussed that ADHD is an early age onset disorder, but the concept of “late-onset ADHD” is also debated in the literature (Caye et al., 2017; Cooper et al., 2018). The previous versions of DSM involved statements more likely to apply to children and adolescents. However, the most recent version of DSM (DSM-5) has expanded these statements and given examples to the statements involving all age groups. For instance, in the DSM-IV, the statement “often loses things necessary for task activities” applied to toys, school- related activities or items. In DSM-5, these examples were expanded to items which also apply to adults (e.g., wallets, paperwork, keys). Conversely, a significant number of adults with ADHD do not receive a diagnosis until later in life (Johnson et al., 2020) which could be due to the age criteria in the previous versions. Nevertheless, since the DSM-5 transition, ADHD diagnoses in young adults have risen by 27% (Matte et al., 2015). The rise in the number of ADHD diagnoses may be positive indicator for improved access for clinical support. Regardless, it also raises concerns about potential “over-diagnosis.” The findings of a scoping review further reinforced this idea, showing increase in diagnoses and pharmacological treatment (Kazda et al., 2021), With the changes in DSM-5 and changing trends in ADHD, it is difficult to determine whether ADHD is over-diagnosed, overtreated or misdiagnosed. Such a condition may have serious consequences, such as potential substance abuse as a result of pharmacological treatment, economic burden on the society as well as the need for new regulations and an updated diagnostic system (Manos et al., 2017).

Considering the changes in the age-onset criteria, diagnosing ADHD in adulthood could be challenging. This is particularly due to the self-report assessment of the childhood symptoms. Adults could struggle recalling the onset of the symptoms, as this part of the assessment heavily relies on retrospective memory (Pallanti and Salerno, 2020).

Moreover, Posner et al. (2020) reported that ADHD is becoming recognized as a dimensional condition, rather than being categorically separated as mild, moderate or severe from non-ADHD individuals, as the DSM-5 states. They further discuss the absence of dimensional models and the questionable practicality of the categorical framework. Additionally, they emphasize that the DSM-5 overlooks the changes in the ADHD presentation across developmental stages. Similarly, inattention symptoms persist into adulthood while visible signs of ADHD often tend to lessen although it is unclear whether this is due to the diagnostic criteria or absolute remission of the symptoms (Faraone et al., 2021).

A recent review by Sadek (2023) emphasized another important limitation of the DSM. The criteria for ADHD in the DSM-5 do not specify that the symptoms are not “substance-induced or are attributable to the physiological effects of another medical condition,” as is written in the criteria for Major Depressive Disorder (MDD). Conditions such as sleep-disordered breathing, thyroid dysfunction, diabetes and typical absence seizures could resemble some ADHD symptoms, potentially resulting in serious consequences. Therefore, consulting a medical practitioner and conducting blood tests to rule out any, the importance of consulting a medical practitioner and running blood tests to rule out any underlying medical conditions is essential.

Diagnostic criteria for ADHD have traditionally been developed using predominantly male child samples. ADHD in women has been often un-recognized due to gender bias in the diagnostic procedure. Females are less likely to be referred for an assessment and they often receive misdiagnosis (Danielson et al., 2018). Notably, that women are more likely to report inattention symptoms, and less hyperactivity or impulsivity compared to boys (Antoniou et al., 2021). Males overall have a higher diagnosis ratio than females which could be due to the under-diagnosis of ADHD in females (Sadek, 2014).

Even though ADHD is believed to be more common in males, it is emerging to be highly recognized in females (Faheem et al., 2022). ADHD is usually diagnosed at an early age, with early signs in toddlers being noticeable between 2 and 3 years of age through irregular sleep patterns (Posner et al., 2020). However, at early ages, the hyperactivity symptoms tend to be more pronounced, and it is a highly predominant symptom in boys. In girls, on the other hand, internalized symptoms; more inwardness, shyness, and inattention are observed (Attoe and Climie, 2023).

Because of the expression of the symptoms, it is more often observed that boys acquire ADHD diagnosis at a young age, much earlier than girls. Regarding older ages, especially in women, non- diagnosed ADHD is generally identified and treated as anxiety or depression (Hinshaw et al., 2022). Consequently, most women are diagnosed with ADHD at a later age (Fairman et al., 2020) and they are generally misdiagnosed, which may also be due to gender bias arising from the traditional nature of ADHD. In addition, as women with undiagnosed ADHD are more likely to experience heightened hormonal shifts that result in higher levels of irritability, emotional dysregulation, mood swings and poor concentration, they may be more likely to receive another diagnosis (Attoe and Climie, 2023). While neurocognitive profiles of adults with ADHD have been studied, gender differences in these cognitive patterns are often overlooked, despite biological and hormonal factors suggesting potential disparities between males and females. Thus, both men and women may be misdiagnosed due to differences in ADHD presentation and gender-related differences.

Recognizing the potential differences in the presentation of ADHD due to gender differences could help reduce the gender gap, however there is a need for improved diagnostic tools (Slobodin and Davidovitch, 2019). Among other tools, DIVA-5 is currently exploring new methods to improve the identification of ADHD symptom presentations in women. This includes investigating symptom differences between men and women and hormonal factors to improve the diagnostic accuracy for women.

ADHD should not be diagnosed if symptoms are solely present during psychotic episodes or could be explained by another mental disorder. Individuals with autism or intellectual disabilities may be diagnosed with ADHD if their symptoms exceed the expected severity for their developmental level. Clinicians must distinguish ADHD from other mental disorders, especially those that share overlapping symptoms, by noting the persistence of inattentive or hyperactive–impulsive symptoms outside of discrete episodes of mood or anxiety issues. When both sets of diagnostic criteria are met, comorbidity should be considered (Hall et al., 2016).

As noted previously, some medical conditions like thyroiditis and diabetes may mimic ADHD symptoms (Sadek, 2023). Evidence-based clinical guidelines also suggest that the use of certain drugs or substances can be a leading factor in the appearance of ADHD-like symptoms and should also be addressed in the diagnostic process (May et al., 2023). Referral for a medical assessment (general examination, blood tests, brain imaging) and taking a medical history may also help to assess all of these factors.

In case of co-existing conditions, it is essential to undertake a thorough evaluation of both overlapping and distinguishing symptoms. To differentiate ADHD from other potential disorders, specific tests can be used in addition to interviews. For example, the Woodcock-Johnson IV (WJ IV), which measures achievement, cognitive abilities, and oral language, is an ideal scale for identifying potential learning disabilities (LD) (Schrank and McGrew, 2015). Similarly, for mood and anxiety disorders Child Depression Inventory (CDI) (Kovacs, 2015) and Revised Children’s Manifest Anxiety Scale, Second Edition (RCMAS-2) (Reynolds et al., 2008) could be utilized for detecting whether symptoms only mimic each other or there is comorbidity. Conversely, neuropsychological testing should also be considered for mapping out the impairments more accurately.

The functionality of the chosen tools for the assessment is also very important. First, in child and adolescent assessment, informant-based measures (parents and teachers) of EF, typically indicate greater delays in EF compared to performance-based measures. This discrepancy may arise because informant-based measures capture a child’s challenges in real-life contexts, such as school or home, where everyday demands refer to the difficulties in managing attention, impulsivity, and task completion. However, performance-based measures focus on isolated cognitive tasks that may not fully reflect the overall profile. However, using both measures in the diagnostic process to gain a comprehensive understanding of the child’s EF abilities (Sadozai et al., 2024).

Accurate diagnosis of ADHD requires a methodical approach, involving multiple steps that not only aid in identifying ADHD but also distinguish it from conditions with overlapping symptoms. Sibley (2021) outlines seven steps for accurately diagnosing adult ADHD. First step involves a structured diagnostic interview followed by the second step: self-report ratings and informant ratings. In this step, an utmost importance to informant ratings should be given as patients could over-report or under-report symptoms. To address this, the third step applies the “or rule,” which ensures that the symptom reported by the patient also needs to be endorsed by the informant to confirm its presence. The fourth step focuses on the areas of impairment and analyzing any existing evidence to support the impairment (e.g., academic and medical records, legal documents etc.) and the duration of these symptoms are assessed in the fifth step where the age-onset, the symptom timeline and potential stressors are further evaluated. In the sixth step, differential diagnoses are explored to rule out any alternative mental or medical conditions which may resemble ADHD symptoms. And finally, the last step allows for the establishment of a diagnosis. Following these diagnostic steps and addressing the differential diagnosis process, ADHD could be correctly identified, which would facilitate effective treatment and management.