ADHD, ODD, CD, and DMDD: What You Really Need to Know for Boards (and Practice)

By Dr. Thales Lopes, DNP, PMHNP-BC

When it comes to child and adolescent psychiatry, a few key diagnoses come up again and again on board exams—and in real-life practice. Understanding the nuances between ADHD, ODD, Conduct Disorder, and DMDD is essential for accurate diagnosis, effective treatment, and avoiding common pitfalls.

In this post, I’ll break down each disorder with high-yield facts, clinical pearls, and board-worthy differentiators. Whether you’re reviewing for certification or fine-tuning your clinical skills, this guide is for you.

1. Attention-Deficit/Hyperactivity Disorder (ADHD)

Let’s start with the big one. ADHD is a neurodevelopmental disorder that presents with inattention and/or hyperactivity-impulsivity. It’s more than just being distracted—it’s a condition that impairs functioning.

✳️ The 3 Presentations:

• Inattentive (ADHD-PI): Distracted, forgetful, disorganized. Often missed in girls or misdiagnosed as anxiety or learning disorders.

• Hyperactive/Impulsive (ADHD-HI): Restless, talks excessively, can’t wait turn. Often diagnosed in young boys.

• Combined (ADHD-C): Features of both—this is the most common presentation.

🧠 High-Yield Clinical Points:

• Symptoms must be present before age 12

• Must occur in two or more settings (e.g., home and school)

• Significant functional impairment is required

• Neurobiology: Dysfunction in dopamine and norepinephrine pathways in the prefrontal cortex and striatum

💊 Treatment:

• First-line (kids): Stimulants (methylphenidate ≥6 y/o, amphetamines ≥3 y/o)

• Mechanism: Block DA/NE reuptake

• Side effects: Appetite loss, insomnia, slowed growth, cardiac concerns

• Important warning: If tics emerge, discontinue stimulant immediately

For adults, we also consider atomoxetine, bupropion, clonidine, and guanfacine. Non-med approaches like CBT, parent training, and executive function coaching are essential.

2. Oppositional Defiant Disorder (ODD)

These kids don’t like rules—and they’ll make sure you know it. ODD involves persistent defiance, irritability, and spite, typically aimed at authority figures.

🔑 Core Symptoms:

• Angry/Irritable Mood

• Argumentative/Defiant Behavior

• Vindictiveness (spiteful at least twice in 6 months)

📌 Key Features:

• Behavior is targeted at authority figures, not strangers or peers

• Doesn’t involve aggression, theft, or property destruction

• Severity is based on how many settings it’s observed in

🤝 Differential Tips:

• ADHD: High comorbidity. Treat ADHD first; ODD may improve.

• CD: ODD doesn’t involve serious rule-breaking or aggression.

• DMDD: If both criteria are met, DMDD trumps ODD.

• Normal Defiance: ODD is persistent, impairing, and beyond typical behavior.

🛠️ Treatment:

• Parent Management Training (PMT)

• CBT and family therapy

• Medications for comorbid ADHD or mood issues

3. Conduct Disorder (CD)

This one’s serious. CD involves a pattern of violating rights or major rules, often with aggression and deceit.

💣 Symptoms (3+ in 12 months, 1+ in last 6 months):

• Aggression to people/animals

• Destruction of property

• Deceit or theft

• Serious rule violations (e.g., truancy, running away)

🧊 Specifiers:

• Childhood-Onset: <10 years old. Worse prognosis, more severe.

• Adolescent-Onset: ≥10 years old. Less severe.

• With Limited Prosocial Emotions: Lack of guilt or empathy = “callous-unemotional” traits (big red flag for ASPD risk)

🚨 Why It Matters:

• Major risk factor for Antisocial Personality Disorder (ASPD)

• High comorbidity with ADHD, ODD, substance use

• Often involves the juvenile justice system

💡 Treatment:

• Multisystemic Therapy (MST)

• PMT, residential treatment for severe cases

• Medications for comorbidities or aggression (e.g., antipsychotics, mood stabilizers)

4. Disruptive Mood Dysregulation Disorder (DMDD)

This is a newer DSM-5 diagnosis designed to prevent overdiagnosis of pediatric bipolar disorder. It features chronic irritability and frequent temper outbursts—but without true manic episodes.

🔥 Core Criteria:

• Severe temper outbursts ≥3x/week

• Persistent irritable/angry mood between outbursts

• Symptoms persist ≥12 months, with no 3-month break

• Must be present in 2+ settings (severe in at least 1)

• Onset before age 10; diagnosis between ages 6–18

📋 Differentials to Know:

• ODD: DMDD includes chronic irritability, not just behavioral defiance

• Bipolar Disorder: No manic or hypomanic episodes

• IED: In DMDD, mood is disrupted even between outbursts

💊 Treatment:

• First-line: CBT, parent training

• Medications:

  • SSRIs (if depressive symptoms dominate)

  • Atypical antipsychotics (e.g., risperidone, aripiprazole) for severe irritability

  • Stimulants if comorbid ADHD is present

🎯 Quick Recap: What to Know for the Boards

🧠 Final Thoughts

• Comorbidity is common: Always assess for ADHD, mood disorders, anxiety, and substance use.

• Progression to Watch: ODD → CD → ASPD (especially with callous-unemotional traits)

• Behavioral therapies are foundational across all four disorders

• Medications support—but don’t replace—psychosocial intervention

📚 For a deeper dive, including case studies and practice questions, check out our course PDFs in the NP Exam Coach’s “30-Day Walk to Success” program.

Got questions or want this in a printable format? Let me know—I’m here to help you succeed!

– Dr. Thales Lopes, DNP, PMHNP-BC
Board Certified Psychiatric-Mental Health Nurse Practitioner