ADHD-C: Are There Different Types Of ADHD?

Reviewed by Heather Cashell, LCSW

Published 12/09/2020

Today, many people are struggling to live a happy and healthy life due to the ADHD symptoms they experience daily. Those who do receive a diagnosis often receive the wrong treatment, which hinders their ability to fight through the ADHD symptoms.

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ADHD symptoms are generally grouped into one of two categories -- inattentiveness or hyperactivity/impulsivity. Mental health professionals must distinguish which of the two the individual is experiencing. In some cases, the individual might experience both.

To ensure individuals receive the correct treatment, mental health professionals group ADHD patients into one of three subtypes -- ADHD-PI, ADHD-HI, and ADHD-C. Of the three, ADHD-C is often the hardest to treat. Still, most people don't know these subtypes exist.

So, what is ADHD-C?

ADHD-C, also known as combined type ADHD, is the diagnosis given to an individual experiencing both symptoms -- inattentiveness and hyperactivity/impulsivity. It's a combination of the other two subtypes -- ADHD-PI and ADHD-HI.

Those diagnosed with ADHD-PI are known as the predominantly inattentive type, while those diagnosed with ADHD-HI are known as the predominantly hyperactive-impulsive type. To understand the full meaning behind ADHD-C, you must first understand both ADHD-PI and ADHD-HI's inner workings.

When diagnosing ADHD-PI and ADHD-HI, some criteria must be met -- according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5).

The first requirement is that the individual experiences a minimum of six of the nine major symptoms in that category. For example, if they experience six symptoms related to inattentiveness, they could be diagnosed with ADHD-PI.

The symptoms must be present for a minimum of six months, present in multiple settings, and cause a noticeable strain on the individual's life.

In addition to that, the individual must've shown some signs of symptoms at an early age, generally before the age of 12. The symptoms also can't be the result of another mental health disorder or condition.

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If all these criteria are met for both symptoms -- inattentiveness and hyperactivity/impulsivity -- the individual is diagnosed with ADHD-C (combined type).

Now that you understand the criteria behind the three subtypes of ADHD examine the nine major symptoms observed in each subtype.

1. Predominantly Inattentive Type

Earlier, we mentioned how there were nine major symptoms that mental health professionals used to determine which subtype of ADHD the individual is suffering from. As you can likely imagine, the inattentive type is often linked to difficulty concentrating and paying attention.

Still, that doesn't give the full picture of what this subtype represents. Here are the official nine symptoms that captivate the subtype in-full:

  • The individual is forgetful, especially with day-to-day activities.
  • The individual is always losing items that are needed to complete certain tasks.
  • The individual has a hard time organizing their thoughts and tasks daily.
  • The individual struggles to pay attention when spoken to, even when directly acknowledged.
  • The individual doesn't pay attention to close details and often makes careless, lazy mistakes.
  • The individual is easily distracted by the simplest things, even when they're trying to stay focused or know they need to focus.
  • The individual tries to avoid tasks that take a long time to complete or require a lot of mental/physical effort.
  • The individual struggles to follow directions correctly (if at all) and often stops working before the job or task is finished.
  • The individual can't hold their attention for a long period.

Again, the individual must experience at least six of these symptoms for at least six months. If that criterion is met, the mental health professional can diagnose the individual with ADHD-PI. Of course, they'll also need to confirm that the other symptoms aren't present.

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2. Predominantly Hyperactive-Impulsive Type

Much like in the inattentive type, the hyperactive-impulsive type is home to nine major symptoms that mental health professionals must find in the individual. The symptoms are normal in some people but start to cause problems when combined for a long period.

Let's take a look at the nine major symptoms included in this subtype:

  • The individual often interrupts other people and intrudes into conversations they're not meant to be a part of.
  • The individual is quick to answer a question they don't know the answer to, often out of impulse.
  • The individual always has something to do and acts as if they're 'driven by a motor.'
  • The individual has a hard time resisting climbing on things and running around when it's not allowed or not appropriate.
  • The individual has a habit of tapping his fingers, hands, or feet uncontrollably.
  • The individual struggles to wait their turn, even when they know they have to wait.
  • The individual talks excessively and is often hard to understand because they talk too fast.
  • The individual has a hard time playing with others quietly and often makes a lot of noise during everyday activities.
  • The individual is quick to leave their seat, even when they know they need to remain seated.

As long as the individual experiences at least six of the nine symptoms listed above for more than six months and in multiple settings, they are likely to be diagnosed with ADHD-HI. If the symptoms are met with at least six inattentive symptoms, they'll be diagnosed with ADHD-C.

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Understanding the difference is essential to the individual's progress when fighting this mental disorder, and it's something the mental health professional needs to be an expert with.


ADHD is a serious mental disorder that needs to be dealt with properly if the individual wants to seek a better life. The longer their symptoms go untreated, the longer the disorder has negatively impacted the individual's life.

Over time, science and research have proven how disruptive ADHD is, especially when someone struggles with combined type ADHD (ADHD-C). It affects nearly every area and aspect of their lives, including their mental health, physical health, social health, emotional health, and performance in school or at work.

It affects the individual's ability to form relationships with others, including their family members and parents. It leads many individuals to avoid bonding with their family members and choose to do things by themselves. These behaviors often follow them at school or at work.

Not only does ADHD follow someone into adulthood, but it often follows them throughout the entirety of their life. It doesn't mean the symptoms can't be managed or treated, but it does mean there's no cure for it, and some people are stuck with the symptoms forever.

Since everyone experiences ADHD differently and suffers from different combinations of symptoms, there's no telling just how bad someone's symptoms can get.



Once ADHD is properly diagnosed, the mental health professional can start putting together a treatment plan for the individual. The treatment plan is specific to them and often contains a combination of medication and therapy.

The medication's main goal is to balance the chemicals inside the brain, also known as neurotransmitters. The major neurotransmitters targeted by the medication are serotonin and dopamine (which is also a precursor to norepinephrine). These three neurotransmitters play a major role in ADHD -- as well as other mental health disorders.

As far as therapy goes, the individual is generally recommended to talk therapy -- such as cognitive-behavioral therapy. The main goal behind the therapy is to understand the inner workings of the individual. By learning more about the individual, the therapist can slowly start to correct some of the habits, behaviors, and thoughts.

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In some circumstances, therapy is also recommended to the parents or parent guardians of the individual. They must provide the right environment for the child growing up. Otherwise, the individual may struggle to regulate their behaviors at home.


As common as ADHD is in today's society, many people have ADHD without knowing it. These people may refuse to receive help, don't understand they need help, or know they need help but don't know how to get it.

The longer these individuals go without receiving treatment, the worse their symptoms can get. Eventually, they're lives are disrupted by these problematic behaviors, and they may have no idea what to do. It's a difficult time for anyone and a time when they need support.

At Mind Diagnostics, we take great pride in offering a comprehensive online test for ADHD. It's designed to determine your risk level of developing ADHD. While we can't tell you whether you have it or not, we can direct you to a therapist that can complete the evaluation of your mind and body.

When you're ready to take better care of your mental health, visit our website or our app on your smartphone to take the adult ADHD quiz today!