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How can you tell if someone has ADHD?

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by inattention, hyperactivity and impulsivity. ADHD symptoms often appear in early childhood and can significantly impact a person’s quality of life if left untreated. However, ADHD can be difficult to diagnose, especially in adults, as symptoms may present differently across patients and overlap with other conditions. This article provides an overview of the common signs and symptoms of ADHD and how healthcare professionals make a diagnosis.

What are the symptoms of ADHD?

There are three main categories of ADHD symptoms: inattention, hyperactivity and impulsivity. To receive an ADHD diagnosis, a person must display several ongoing symptoms from either the inattentive or hyperactive/impulsive symptom groups. Some people have a mix of both inattentive and hyperactive symptoms, which is called combined presentation ADHD.

Inattention symptoms include:

  • Difficulty paying close attention to details or making careless mistakes
  • Trouble staying focused during tasks or play
  • Appearing not to listen when spoken to directly
  • Difficulty following instructions and completing tasks
  • Poor organizational skills and inability to prioritize
  • Easily distracted by extraneous stimuli
  • Forgetfulness in daily activities

Hyperactivity and impulsivity symptoms include:

  • Fidgeting, tapping or squirming when seated
  • Inability to sit still during activities
  • Excessive talking
  • Feeling restless during calm activities
  • Constantly on the go or acting as if “driven by a motor”
  • Impatience
  • Difficulty waiting turns
  • Interrupting conversations or intruding on others

What are the causes and risk factors for ADHD?

The exact causes of ADHD are not fully understood, but research suggests genetics and environmental factors both play a role. Possible risk factors include:

  • Family history of ADHD – ADHD can run in families, indicating a genetic component.
  • Premature birth or low birth weight
  • Brain injury from trauma or infection
  • Exposure to environmental toxins like lead
  • Alcohol or tobacco use during pregnancy

Additionally, ADHD appears to involve an imbalance or deficiency in certain neurotransmitters (chemical messengers) in the brain like dopamine and norepinephrine. Imaging studies show differences in brain structure and activity between people with and without ADHD.

When do ADHD symptoms start?

ADHD symptoms typically emerge in early childhood between the ages of 3-6 years, when a child begins structured schooling and needs to focus more. However, inattentive symptoms in particular are sometimes overlooked in young girls and less hyperactive children. Many people do not receive an ADHD diagnosis until adolescence or adulthood.

For an ADHD diagnosis, some hyperactive, impulsive or inattentive symptoms must have been present before age 12, according to the DSM-5 diagnostic criteria. In adults, symptoms may present more subtly as restlessness, disorganization, mood swings, hot temper, or an inability to complete tasks and follow through on responsibilities.

How is ADHD diagnosed?

There is no single medical, physical or genetic test for ADHD. A comprehensive diagnostic process involves:

  • Physical exam to rule out other possible causes for symptoms
  • Interviews, questionnaires and rating scales to assess symptom history
  • Input from parents, teachers, spouses or other close connections
  • Cognitive and behavioral assessments
  • Review of school and medical records

A doctor or mental health professional looks for evidence of ongoing ADHD symptoms that impair functioning, emerged in childhood, and cannot be better explained by another condition. Common co-occurring conditions that need to be ruled out include learning disabilities, anxiety, depression, bipolar disorder, substance abuse and sleep disorders.

What are the treatment options for ADHD?

While there is no cure for ADHD, currently available treatments can effectively manage symptoms. Multimodal treatment that addresses ADHD on several fronts is usually most effective. Treatment options include:

  • Medication – Stimulant medications like methylphenidate (Ritalin) and amphetamine-based stimulants (Adderall) are commonly prescribed to treat ADHD. Non-stimulant medications like atomoxetine (Strattera) or alpha-agonists like guanfacine (Intuniv) may also be used.
  • Psychotherapy – Cognitive behavioral therapy helps patients identify and adopt strategies to minimize ADHD symptoms and strengthen organizational, social and problem-solving skills.
  • Education and training – Education for both the patient and family can help them understand ADHD, identify triggers and implement management techniques. ADHD coaching may also help.
  • Lifestyle changes – Structured schedules, organization systems, proper nutrition, exercise and sleep hygiene help manage ADHD.
  • School/work accommodations – Individualized education programs, 504 plans and workplace accommodations like adjusted work hours, reduced distractions or permission to work while standing can support ADHD patients.

Treatment needs change over time. Ongoing follow-up and monitoring is key to ensure therapies remain effective as a patient’s challenges evolve.

What are some myths and facts about ADHD?

There are many common misconceptions about ADHD. Here are some myths and corresponding facts:

Myth Fact
ADHD is not a real medical disorder, just bad behavior. ADHD is a legitimate neurodevelopmental disorder with genetic and environmental causes resulting in atypical brain function.
Children eventually outgrow ADHD. Up to 80% of people with childhood ADHD continue experiencing symptoms as adults, which can significantly impact work, relationships and mental health if left unaddressed.
Medication is the only treatment for ADHD. While medication is highly effective for many, multimodal treatment including psychotherapy, skills training, lifestyle changes and school/workplace accommodations is the most comprehensive approach.
ADHD is overdiagnosed. Stringent, research-based diagnostic criteria minimizes overdiagnosis. Many children and adults with ADHD remain undiagnosed and untreated.

What conditions are similar to ADHD?

Several other conditions share similarities with ADHD, which is why a thorough professional evaluation is important for an accurate diagnosis. Similar conditions include:

  • Learning disabilities – Reading, writing, math or speech difficulties are common in ADHD but alone do not indicate it.
  • Mood disorders – Anxiety, depression and bipolar disorder can overlap with ADHD.
  • Sleep disorders – Sleep apnea, restless leg syndrome and circadian rhythm disorders like DSWPD cause daytime fatigue and inattention.
  • Substance use – Chronic drug and alcohol abuse can mimic or exacerbate ADHD symptoms.
  • Sensory processing disorder – Unusual sensitivity to sensory stimuli causes distracting responses similar to ADHD.
  • PTSD – Post-traumatic stress disorder can include poor concentration, irritability and restlessness.

However, having ADHD also increases the risk for certain of these conditions, like learning disabilities and anxiety. An experienced clinician can tease out primary vs. secondary symptoms to make an accurate ADHD diagnosis.


ADHD is a manageable neurodevelopmental disorder characterized by ongoing inattention, hyperactivity and impulsivity. While frequently thought of as a childhood condition, ADHD often persists into adolescence and adulthood and should not be overlooked. Diagnosis requires assessing symptom history, input from close connections, cognitive testing, and ruling out other possible causes. Treatment is customized based on the individual but often includes stimulant medications, psychotherapy, education, skills training and lifestyle adaptations. With proper treatment and support, people with ADHD can thrive academically, socially and professionally.