ADHD is often used as a catch-all label for symptoms like forgetfulness, impulsivity, emotional overwhelm, or difficulty focusing. But just because a person feels distracted or disorganized doesn’t mean ADHD is the cause.
Many mental health and neurological conditions share overlapping symptoms with ADHD — and without a thorough, structured assessment, misdiagnosis is common.
Below are several conditions that are frequently confused with ADHD, including what sets them apart and how an experienced clinician can help distinguish them.
1. Anxiety Disorders (e.g., GAD, Social Anxiety, Panic Disorder)
Overlap with ADHD:
- Trouble focusing, restlessness
- Racing thoughts mistaken for distractibility
- Avoidant behaviours that mimic executive dysfunction
What helps differentiate:
- Inattention in anxiety is often situational and linked to worry or fear; ADHD-related inattention is more constant and not tied to anxious thoughts.
Reference: Ramsay, J. R. (2010). Cognitive therapy for adult ADHD
2. Depression (e.g., Major Depressive Disorder, Dysthymia)
Overlap with ADHD:
- Fatigue, poor memory and concentration
- Low motivation or slowed cognitive processing
What helps differentiate:
- Inattention is usually episodic and linked to low mood. ADHD-related attention difficulties are more persistent and not mood-dependent.
Reference: Sobanski, E. (2006). Psychiatric comorbidity in adults with ADHD
3. Autism Spectrum Disorder (ASD)
Overlap with ADHD:
- Executive dysfunction, sensory sensitivities
- Social differences and emotional regulation difficulties
- Intense focus or restricted interests
What helps differentiate:
- ASD involves differences in social communication and patterns of repetitive behaviour not seen in ADHD. Many people meet criteria for both.
Reference: Leitner, Y. (2014). The co-occurrence of autism and ADHD
4. Learning Disabilities (e.g., Dyslexia, Dyscalculia, Auditory Processing Disorder)
Overlap with ADHD:
- Poor academic performance
- Avoidance of reading/writing tasks
- Seeming off-task or unengaged
What helps differentiate:
- Cognitive testing can reveal specific processing challenges, whereas ADHD affects attention across many areas.
Reference: Mayes & Calhoun (2007)
5. PTSD / Complex Trauma
Overlap with ADHD:
- Emotional dysregulation, impulsivity
- Flashbacks that resemble “zoning out”
- Poor concentration and hyperarousal
What helps differentiate:
- PTSD symptoms are trigger-based and include re-experiencing or avoidance, which are not typical of ADHD.
Reference: Ford et al. (2000)
6. Bipolar Disorder (Especially Bipolar II or Cyclothymia)
Overlap with ADHD:
- Distractibility and impulsivity during elevated mood
- Risk-taking or agitation
What helps differentiate:
- Bipolar symptoms occur in episodic mood states (highs/lows), while ADHD is more consistent day-to-day.
Reference: Wingo & Ghaemi (2007)
7. Sleep Disorders (e.g., Insomnia, Sleep Apnea, Narcolepsy)
Overlap with ADHD:
- Daytime inattention or forgetfulness
- Low energy, irritability, poor executive function
What helps differentiate:
- Sleep assessments often uncover underlying sleep deprivation. Treating sleep can resolve cognitive symptoms.
Reference: Owens (2009)
8. Substance Use Disorders
Overlap with ADHD:
- Disorganization, poor judgment
- Emotional instability or attention lapses
What helps differentiate:
- Symptoms in substance use fluctuate with usage and typically follow a different trajectory than ADHD.
Reference: Wilens et al. (2008)
9. Borderline Personality Disorder (BPD)
Overlap with ADHD:
- Emotional instability, impulsivity
- Risk-taking and interpersonal difficulties
What helps differentiate:
- BPD involves unstable relationships, identity struggles, and a pattern of intense emotional reactions, which go beyond typical ADHD symptoms.
Reference: Philipsen (2006)
How a Comprehensive Assessment Helps Clarify the Diagnosis
At Downtown Psychology Clinic, we go beyond checklists. Our assessments are designed to carefully explore what’s really going on — even when symptoms look like ADHD on the surface.
What Our ADHD Assessments Include:
- Clinical Interview: Timeline of symptoms, history, and functioning
- Standardized Tools: ADHD scales + broader psychological measures
- Cognitive Testing: To explore executive function and rule out learning disabilities
- Collateral Input: Reports from teachers, partners, or family (when available)
- Recognized Diagnostic Frameworks: Using DSM-5-TR, with a focus on nuance
- Formulation, Not Just Labels: Recommendations tailored to your unique profile
Clarifying the “Why” Behind Your Struggles
A formal diagnosis — or even a well-formulated explanation without a diagnosis — can reframe years of confusion or self-blame. It opens doors to meaningful support, new strategies, and more self-compassion.
You don’t need to have all the answers before reaching out.
At Downtown Psychology Clinic, we offer compassionate, comprehensive assessments that recognize the whole person, not just a checklist of symptoms.
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The content of this blog is for informational purposes only, and is not intended to be a substitute for professional medical or psychological advice, diagnosis or treatment. Always seek the advice of your mental health provider or physician with any questions that you have regarding mental health concerns. If you think you have an emergency, please call 911 or visit your nearest emergency room.
