What Age Is ADHD Combined Type Usually Diagnosed? 

ADHD Combined Type is often diagnosed earlier than other subtypes, as it includes both inattentive and hyperactive-impulsive symptoms. Behaviours such as impulsivity, difficulty focusing, and disruptive actions typically prompt referrals during early school years. 

Typical Diagnosis Age for Combined ADHD 

Diagnosis usually occurs between ages 6 and 8, although signs may be noticeable as early as age 4. In structured environments like classrooms, the overlap of inattentive and hyperactive-impulsive traits makes Combined ADHD more apparent. Boys are often diagnosed earlier due to more overt behaviours, whereas girls’ subtler symptoms may go unnoticed. 

Factors That May Delay Diagnosis 

Combined ADHD is often diagnosed late because hyperactive-impulsive symptoms can be subtle or masked, especially in some individuals. Gender bias and the tendency to attribute behaviors to personality or environment also contribute to the delay 

• Gender Differences: Girls often display less disruptive behaviours, which can lead to underdiagnosis. 

• Environmental Factors: Assessment may be delayed by obstacles related to family, education, or healthcare. 

• Symptom Masking: Mild or concealed symptoms might be misattributed to personality traits or environmental factors. 

What to Do If You Suspect Combined ADHD 

If you recognise the signs of ADHD Combined Type, consider speaking to your GP for an NHS referral, keeping in mind that waiting times may apply. You can also explore private assessments for both adults and children through ADHD Certify . Start by taking our free self-assessment to check your symptoms. To learn more about how this subtype compares to others, read our full guide: What is ADHD Combined Type