Distinction between Episodic Mood Disorder and Attention Deficit Disorder with Hyperactivity based on their Association with the Main Classes of International Classification of Disease in a Child and Adolescent Population

Research Article

Ann Depress Anxiety. 2016; 3(1): 1073.

Distinction between Episodic Mood Disorder and Attention Deficit Disorder with Hyperactivity based on their Association with the Main Classes of International Classification of Disease in a Child and Adolescent Population

Chartier G1 and Cawthorpe D2*

1Department of Psychiatry, University of British Columbia, Canada

2Department of Psychiatry & Community Health Sciences, University of Calgary, Canada

*Corresponding author: David Cawthorpe, Department of Psychiatry & Community Health Sciences, University of Calgary, Canada

Received: March 25, 2016; Accepted: April 07, 2016; Published: April 12, 2016


Background: Few studies comprehensively examine specific mental disorders in terms of associated bio-medical comorbidities with focus on the pattern of similitude and distinction. The present study compares the profile of independent classes of physical disorder for Episodic Mood Disorder (EMD), Attention-Deficit Disorder with Hyperactivity (ADHD) and all Other Mental Disorders (OMD).

Methods: Physician billing data for 235893 individuals up to 18 years old spanning sixteen fiscal years (1994-2009) in Calgary, Alberta, was compiled, permitting the examination of Odds Ratios (ORs) comparing the main classes International Classification of Diseases (ICD) within each of four groups of psychiatric disorders: EMD, ADHD, both EMD/ADHD and OMD.

Results: Each group profile was distinct: The EMD group presented Odds Ratios (OR) greater than ADHD and all other mental disorder across most ICD classes. For both sexes, ADHD and EMD differed significantly in profile across 11 independent ICD disorder classes, with an additional three classes being specific to females and one specific to males. The ADHD group ORs tended to be lower than the EMD group and the OMD group.

Conclusion: This study represents the premiere pediatric populationbased report on the patterns of main class ICD disorders associated with EMD and ADHD and OMD. In opposition with most research focusing on EMD and ADHD, the different clinical profile pattern of ICD disorders for EMD and ADHD disorders suggest an independent etiology. Profiling comorbidity represents a novel approach to understanding disease and etiology.

Keywords: Attention deficit hyperactivity disorder; Episodic mood disorder; Comorbidity; Population; Epidemiology; International classification of diseases


ADHD: Attention Deficit Hyperactivity Disorder; CI: Confidence Intervals; EMD: Episodic Mood Disorder; ICD: International Classification of Diseases; OMD: Other Mental Disorders; OR: Odds Ratio


There is overlap of the descriptive criteria underpinning the definition and diagnosis of different mental disorders. Furthermore, much research has focused on common etiology or shared liability or comorbidity of Attention Deficit Hyperactivity Disorder (ADHD), Episodic Mood Disorder (EMD) and other mental disorders in pediatric populations [1-3]. This report supports the contention that ADHD and EMD are distinct entities based on their respective physical disorder profiles.


There has been debate regarding the associations and etiology of EMD and ADHD [4-12]. Research has distinguished between subtypes of chronic and episodic irritability in youngsters, however has not associated chronic and episodic irritability with particular mental disorders [13]. Others have associated early-onset chronic irritability, a feature of EMD, with ADHD [14,15]. Furthermore, studies have identified EMD to be associated with a range of child psychiatric disorders [16-18]. Overlapping symptoms can account for some observed comorbidity in studies [19], however, the application of diagnostic criteria in clinical settings may be influenced by the clinician background and orientation. For example, clinicians are influenced by the debate regarding the phenomenology of EMD, as this relates to diagnostic criteria as applied in children, in addition to its relationship to other childhood mental disorders [20]. While the improvement of diagnostic precision helps to resolve difficulties in establishing the independence of specific child disorders, another approach to understanding these differences may derive from an examination of the physical disorder profiles associated with specific childhood disorders, such as EMD and ADHD. The present study reports on the annual prevalence of EMD and ADHD, in addition to the similarities and differences in comparing the profiles of major class International Classification of Diseases (ICD) of those with EMD and ADHD in relationship to those with both EMD/ADHD and all Other Mental Disorders (OMD).


Using a population sampling frame, the unique identifiers of 238303 individuals (51% male) up to 18 years of age were selected from the regional health service registry in the Calgary health zone (Calgary, Alberta, Canada) and merged with all direct physician billings (n =10802484) from 1993-2010 for treatment of any presenting concern, resulting in 16 years of fiscal data (1994-2009). Each billing record pertains to services rendered to patients on specified dates resulting in the assignment of an ICD diagnostic code. This study employed an anonymous data set that included International Classification of Diseases (ICD) diagnoses, visit date, age at index visit, and sex.

The annual population rates of the diagnostic groupings were based on the number of unique individuals diagnosed by a physician with ADHD or EMD, or both, or any other mental disorders in any given year, denominated by the civic census of those up to 18 years of age from 1994-2009. The 16-year prevalence was based on the total number of unique individuals diagnosed denominated by a standardized base population (e.g., 2001).

The data was collapsed into four basic groups representing the dependent variables: Presence or absence of EMD (+/-EMD) or ADHD (+/-ADHD), or both EMD and ADHD (+/- BOTH) or any other mental disorder (+/-OMD). EMD did not include schizophrenia, or single or recurrent Major Depression, but included Manic Depressive Disorder, Bipolar Affective Disorder, and Affective Psychosis NOS). These three dependent variables were expressed as the odds ratios of the remaining classes of ICD disorders including V codes (independent variables) as compared to the base category, those without mental disorder. Differences were based on a comparison of overlapping and non-overlapping 95% confidence intervals. For rates, significant statistical differences between proportions in any given year were estimated by comparison of the 95% confidence intervals using the standard formula, wherein non-overlapping 95% confidence intervals represent significant differences (p < 0.05, with z set to 1.96). The sexes were examined separately.

In each case (Table 1), column a represents those without any psychiatric diagnosis or the independent main ICD class disorder, column b represents the frequency of those with the independent man ICD class disorder and without the dependent mental disorder (OMD, EMD, ADHD, both ADHD/EMD), column c represents those without the independent man ICD class disorder and with the dependent mental disorder (OMD, EMD, ADHD, both ADHD/ EMD), column d represents those with both the independent man ICD class disorder and the dependent mental disorder (OMD, EMD, ADHD, both ADHD/EMD). Calculation of the odds ratio was based on the formula OR = [(ad)/(bc)].