John Harrow, PhD
Naperville Testing Psychologist

Owner and Licensed Clinical Psychologist

Welcome! It’s so nice of you to drop by my profile! As a licensed psychologist, I’m eager to partner with you or your family to build the clarity you deserve and streamline your path to mental wellness.

HOWEVER.

In the interests of informed consent, there are a few quick facts you should know about me. I am an unrepentant night owl with a natural bedtime of ~5 AM. I actually enjoyed grad school. My favorite meal of the day is donuts. I am guilty of discussing The Lord of the Rings as if I have read the entire trilogy (I’ve only seen the movies). I have never had a pet, but I am prenuptially-obligated to own a dog at some point in the next three-to-five years.

Unrelatedly, I am the OG productive procrastinator. I will happily clean my whole house if it delays a trip to the grocery store.

Ok. Let’s dive in.

My Creds:

Ph.D. in Psychology: University of Illinois at Urbana-Champaign

Clinical Psychologist (IL License #: 071.010658)

When We Meet, Ask Me...

…how NOT to ask your future wife to marry you in San Francisco.

…how many miles I biked last year.

…what possessed me to zipline over the Costa Rican rainforest on my honeymoon.

…why the BEST breakfast you’ll ever have is located in PHX International Airport.

John Harrow Naperville testing psychologist

My Credentials:

Ph.D. in Psychology: University of Illinois at Urbana-Champaign

Clinical Psychologist (IL License #: 071.010658)

A man proposing to a woman in a redwood forest

The Work We Do Together...

...is to make sense of it all.

I am an experienced testing psychologist with a deep mastery of neuropsychological and psychological assessments for those seeking accommodations in work or school. I have administered over 500 evaluations for clients seeking clarity on struggles such as depression, anxiety, ADHD, autism, and learning disabilities. My streamlined approach to assessments ensures clients receive comprehensive reports without waiting months for testing results.

My therapy work with clients and families focuses on building confidence, autonomy, and social skills to tackle life’s challenges. I have over a decade of experience serving adults, teens, and families in therapy.

What Does Testing Look Like?

Testing with me typically involves an intake session, testing administration, and a feedback session. To make things easy on my clients, intakes and feedback sessions can be virtual. During testing, my clients complete gold-standard measures of cognitive, neuropsychological, mood, anxiety, and personality functioning. Some of these measures may seem like games, some are questionnaires, and some involve us having a chat and answering questions verbally. Throughout testing, my objective is to keep the process as simple and transparent as possible to get you to the next step: deep diagnostic clarity and access to the care and support you or your child need.

A man wearing a bicycle helmet and sunglasses looking directly into the camera
A plate with a large waffle on it with a side of bacon in addition to syrup and butter

My Specialties

I administer psychological evaluations for all clients aged 3 and older. I hold certification in ADOS-2 administration for comprehensive autism evaluations, including those required by applied behavior analysis (ABA) programs. I also administer presurgical testing to support clients planning to improve their lives through bariatric or pain management surgery.

In terms of my therapeutic approach, I lean on an integrated mix of cognitive behavioral therapy, dialectical behavior therapy, and motivational interviewing. I adore clients who are serious about cultivating real change and don’t back down from a challenge, whether circumstantial or conversational.

Let's Face It...

Life and relationships can be tough. For some, building connections seems effortless. You know who I’m talking about. The coworker with (a little too much) energy to spare; the class clown who never fails to get a laugh; the relative who jumps at the chance to host the next family gathering. For others, moving through the world sparks anxiety that causes us to fall back on unhealthy patterns and creates conditions for suffering.

Success in testing and therapy depends on the ability of the psychologist and client to connect genuinely and openly. I work with clients to forge a strong foundation for growth based on their individual needs and the latest evidence-based practices. If you or your family are struggling to access necessary supports or feel stuck in your mental wellness journey, please don’t hesitate to reach out today.

(Oh, and bring donuts.)

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Ready to Schedule with Dr. Harrow?

Want to Learn More about Testing?

Ready to Schedule with Dr. Harrow?

Want to Learn More about Testing?

My FAQs

Here are answers to questions I hear from clients most often!

Many adults pursue ADHD testing when they notice ongoing challenges with focus, organization, time management, or follow-through, especially when these issues persist despite strong effort or high intelligence. Adult ADHD often shows up as inconsistency rather than inability. A comprehensive ADHD evaluation can clarify whether these patterns are related to ADHD and provide specific recommendations for improving daily functioning at work, school, and home.

At Tailwinds, the neuropsychological testing process is designed to be both thorough and efficient. Most ADHD testing and neuropsychological evaluations are completed within one to two weeks from start to finish, including a detailed report. In many cases, results can be available in under a week, allowing clients to move forward quickly with treatment, accommodations, or next steps.

Yes. We provide ADHD testing, autism testing, and comprehensive neuropsychological evaluations for adults, teens, and children in Naperville and throughout the western suburbs of Chicago. Our goal is to offer timely access to high-quality psychological testing without the long waitlists or delays that are common in many settings.

Autism in adults often presents as differences in social communication, sensory sensitivities, preference for structure, and feeling overwhelmed in unstructured or social environments. Many individuals develop strong coping strategies or “masking” skills, which can make these traits less obvious. A formal autism evaluation can help clarify these patterns and provide insight into both strengths and challenges.

A comprehensive psychological evaluation typically includes a clinical interview, standardized testing, and questionnaires that assess attention, memory, executive functioning, and emotional patterns. The process is collaborative and tailored to your specific concerns. After testing, you receive a detailed, easy-to-understand report with clear findings and actionable recommendations.

When conducted using evidence-based measures and a comprehensive approach, ADHD and autism testing are highly reliable. A thorough evaluation looks at multiple sources of information—including test performance, history, and current functioning—to ensure an accurate diagnosis. This approach helps differentiate ADHD or autism from other factors such as anxiety, depression, or stress.

Yes. Psychological testing can provide the documentation needed for accommodations in academic or professional settings, such as extended time, reduced distractions, or workplace modifications. Reports are designed to be clear, comprehensive, and useful for schools, employers, and other providers.

Absolutely. Many high-achieving individuals with ADHD or autism develop strong compensatory strategies that allow them to succeed professionally while still experiencing significant internal strain. Difficulties with focus, organization, burnout, or social demands may still be present. Testing can help explain these patterns and identify more efficient ways of functioning.

Our approach emphasizes both depth and efficiency. We provide comprehensive, high-quality psychological and neuropsychological testing with a faster turnaround than many traditional settings. Reports are detailed yet practical, with clear next steps and recommendations, and we work closely with clients to help them translate results into meaningful changes.

The best first step is to schedule a consultation to discuss your concerns and determine whether testing is appropriate. From there, we can outline a clear plan for evaluation and next steps. Early clarity often leads to more targeted support and better outcomes over time.

The cost of neuropsychological testing can vary depending on the type and scope of the evaluation, such as ADHD testing, autism testing, or a more comprehensive neuropsychological assessment. At Tailwinds, we provide clear, upfront information about costs before beginning the process, so there are no surprises. In many cases, testing may be partially reimbursable through out-of-network insurance benefits. We’re also happy to walk you through your options so you can make an informed decision about care.

Many people begin to wonder about ADHD when they notice persistent difficulties with focus, organization, time management, or follow-through—especially when these challenges don’t match their level of ability or effort. Adults with ADHD often describe feeling inconsistent, easily overwhelmed, or chronically behind despite strong intentions. While online checklists can be a helpful starting point, a comprehensive ADHD evaluation is the most reliable way to determine whether ADHD is present and to better understand how your brain works.

People often explore the possibility of autism when they notice longstanding patterns in social communication, sensory sensitivity, or a strong preference for structure and routine. Many adults (especially those who are high-functioning) have developed ways of adapting or “masking,” which can make these traits less obvious over time. A formal autism evaluation provides a deeper understanding of these patterns, helping clarify whether they are consistent with autism and offering guidance on next steps and support.

Parents often begin to consider ADHD when a child shows ongoing difficulties with attention, impulse control, or hyperactivity that are affecting school performance, behavior at home, or relationships with peers. This might look like trouble staying focused, frequent forgetfulness, difficulty following instructions, or acting without thinking. While some of these behaviors are part of typical development, ADHD is characterized by patterns that are more persistent and impactful than expected for a child’s age. A comprehensive ADHD evaluation can help determine whether these challenges are consistent with ADHD and provide clear recommendations for support at home and school.

Autism is often considered when a child shows differences in social communication, play, or behavior compared to peers. This can include reduced eye contact, difficulty with back-and-forth conversation, strong preferences for routines, sensory sensitivities, or highly focused interests. Every child develops differently, but when these patterns are consistent and impact daily functioning, an autism evaluation can provide clarity. A thorough autism assessment helps identify strengths and challenges while offering guidance on how to best support your child’s development.

ADHD and autism can share some overlapping features, but they reflect different patterns of development. ADHD is primarily related to attention, impulsivity, and hyperactivity—children may struggle with focus, organization, and self-control. Autism, on the other hand, involves differences in social communication, sensory processing, and patterns of behavior, such as a preference for routines or highly focused interests. Some children may show traits of both, which can make things feel confusing. A comprehensive evaluation helps clarify these differences and ensures that each child receives the most appropriate support based on their unique profile.

Children can be evaluated for ADHD or autism as early as concerns begin to emerge, often during the preschool or early elementary years. For ADHD, many evaluations occur once a child is in a structured school setting where attention, organization, and behavior expectations are clearer. Autism evaluations can take place even earlier if there are concerns about social communication, language development, or behavior. If you’re noticing patterns that feel different from other children your child’s age, it’s reasonable to seek an evaluation. Early clarity can lead to more targeted support and better long-term outcomes.