How Do Executive Functions Differ in Children with Disruptive Mood Dysregulation Disorder?

What you need to know

• Children with disruptive mood dysregulation disorder (DMDD) show more difficulties with emotional control and cognitive flexibility in daily life compared to children with ADHD.
• Higher levels of irritability are associated with poorer emotional control and cognitive flexibility in children’s everyday functioning.
• Children with DMDD do not show deficits on performance-based tests of executive function, suggesting their difficulties may be specific to emotionally-charged real-world situations.

Understanding DMDD and Irritability

Disruptive mood dysregulation disorder (DMDD) is a relatively new psychiatric diagnosis characterized by chronic irritability and frequent, severe temper outbursts. Irritability refers to a heightened tendency to feel frustrated and angry. While occasional irritability is normal, persistent and intense irritability in children can be a sign of DMDD or other mental health issues.

DMDD was added to the DSM-5 diagnostic manual in 2013 to address concerns about potential overdiagnosis of bipolar disorder in children. It aims to provide a more accurate diagnosis for children with chronic irritability and emotional dysregulation who do not meet criteria for bipolar disorder.

This study sought to better understand the cognitive and emotional difficulties associated with DMDD by examining executive function skills in children with DMDD compared to other related disorders. Executive functions are a set of cognitive processes that allow us to plan, focus attention, remember instructions, and juggle multiple tasks. They play a key role in regulating our thoughts, emotions, and behaviors.

How the Study Was Conducted

The researchers recruited 208 children aged 6-12 who had been referred to child psychiatric clinics in Norway. They used diagnostic interviews to identify children who met criteria for DMDD, attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), or combined DMDD+ADHD.

Executive function was assessed in two ways:

1. Parent reports of children’s executive skills in daily life using the Behavior Rating Inventory of Executive Function (BRIEF-2) questionnaire.

2. Performance-based tests where children completed tasks measuring skills like inhibition, cognitive flexibility, and working memory.

The researchers also measured irritability levels in all children using parent ratings.

Key Findings on Executive Function in DMDD

Daily Life Executive Function

In assessments of real-world executive skills based on parent reports:

• Children with DMDD showed significantly worse emotional control compared to children with ADHD. This means they had more difficulty managing and regulating their emotional responses in everyday situations.

• The DMDD group also showed clinically elevated scores (i.e. clear problems) in cognitive flexibility compared to normal levels. Cognitive flexibility refers to the ability to adapt thinking and behavior in response to changing situations.

• Children with DMDD had significantly fewer working memory problems than those with ADHD. Working memory involves holding information in mind and mentally working with it.

• There were no significant differences in executive function ratings between children with DMDD and those with ODD.

Performance-Based Executive Function

On laboratory tests of executive skills:

• No significant differences were found between the DMDD, ADHD, and ODD groups on any measures of executive function.

• All groups performed within the normal range on these tests.

This pattern suggests that children with DMDD may have intact basic executive function skills when assessed in structured, emotionally-neutral testing environments. However, they struggle to apply these skills effectively in real-world situations that are more emotionally charged or less structured.

The Role of Irritability

The researchers also examined how irritability levels related to executive function across all children in the study, regardless of diagnosis. They found:

• Higher levels of irritability were associated with greater difficulties in emotional control and cognitive flexibility in daily life.

• Irritability was not related to performance on laboratory tests of executive function.

This aligns with the findings on DMDD, suggesting that irritability may interfere with the application of executive skills in emotionally-relevant real-world contexts, rather than impairing the core cognitive abilities themselves.

Implications for Understanding DMDD

These results provide important insights into the nature of cognitive and emotional difficulties in children with DMDD:

1. Emotional dysregulation appears to be a key feature that distinguishes DMDD from ADHD. While both groups struggle with aspects of executive function, children with DMDD show particular difficulty controlling their emotional responses.

2. The executive function difficulties in DMDD seem to be context-specific, emerging in emotionally-charged real-world situations rather than in neutral testing environments. This suggests the problem may lie more in applying executive skills when emotions run high, rather than in the executive abilities themselves.

3. The similarity in executive profiles between DMDD and ODD raises questions about whether these should be considered distinct disorders or variations of the same underlying issue. More research is needed to clarify the boundaries between these conditions.

4. Irritability appears to play an important role in driving executive function difficulties in daily life, regardless of specific diagnosis. This highlights the need to assess and address irritability when treating children with emotional and behavioral challenges.

Practical Implications

These findings have several implications for assessing and treating children with DMDD and related issues:

1. Assessment of executive function in DMDD should include both laboratory tests and real-world measures to capture the full picture of a child’s strengths and difficulties.

2. Interventions for DMDD may need to focus specifically on improving emotional control and cognitive flexibility in everyday situations, rather than on enhancing core executive skills.

3. Teaching children strategies to recognize and manage their irritability could help improve their overall executive functioning in daily life.

4. The intact executive skills observed in structured testing environments could potentially be leveraged as a strength in treatment. Children might be taught to apply these skills more effectively in emotional situations.

5. Given the overlap in symptoms and executive profiles, some treatment approaches for ODD may also be applicable to children with DMDD.

Limitations and Future Directions

It’s important to note some limitations of this study:

• The sample sizes for each diagnostic group were relatively small, which may have limited the ability to detect some group differences.

• The study relied heavily on parent reports, which can be subjective. Future research using more objective measures of real-world executive function would be valuable.

• This was a cross-sectional study, so it cannot determine causal relationships between irritability, executive function, and DMDD symptoms. Longitudinal research is needed to clarify how these factors influence each other over time.

Future studies should also explore:

• The neural mechanisms underlying the link between irritability and executive function difficulties in emotional contexts.

• Whether improving executive function skills, particularly emotional control and cognitive flexibility, leads to reductions in DMDD symptoms.

• How executive function profiles in DMDD may change with age and development.

Conclusions

• Children with DMDD show particular difficulties with emotional control and cognitive flexibility in daily life, despite performing normally on structured executive function tests.

• Higher levels of irritability are associated with greater executive function problems in real-world contexts across diagnoses.

• These findings suggest that DMDD involves a specific deficit in applying executive skills in emotional situations, rather than a global impairment of executive abilities.

• Assessing and addressing irritability and context-specific executive function difficulties may be key to effectively treating DMDD and related emotional/behavioral disorders in children.