Understanding ADHD and Co-Occurring Disorders

Medically reviewed by Dr. Mark Hrymoc, M.D.

October is ADHD Awareness Month, and the best way to participate is to learn more about the ADHD and co-occurring conditions that often accompany the disorder.

ADHD is treatable and easy to manage with the help of a mental health team, including a psychiatrist and therapist. Sharing education on ADHD helps reduce the stigma about getting proper treatment. The more you understand it, the better you can help yourself or someone you know seek help.

What is ADHD?

ADHD stands for attention deficit hyperactivity disorder, which can appear in three ways: inattention, hyperactivity and impulsivity, or a combination.

To be diagnosed with ADHD, you must meet the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM5). The requirements include the following:


For someone to have attention deficits, they must have symptoms for at least six months. For children 16 and younger, they must have six or more symptoms. For anyone over 17, they must have five or more symptoms. The symptoms may be:

  • Makes careless mistakes or can’t pay attention to more minor details.
  • Quickly loses attention in an activity.
  • Doesn’t seem to listen when given instructions.
  • Fails to complete tasks or jobs due to losing focus or distractions.
  • Struggles with staying organized.
  • Tries to avoid engaging in activities that take a long time to complete.
  • Loses things like glasses, homework, cell phone, etc.
  • Is easily distracted.
  • If forgetful

Hyperactivity and Impulsivity

Someone must have symptoms for at least six months to have hyperactivity and impulsivity. For children 16 and younger, they must have six or more symptoms. For anyone over 17, they must have five or more symptoms. The symptoms may be:

  • Fidgeting, tapping, or struggling to sit still.
  • Doesn’t stay seated even when instructed to do so.
  • Moves around or climbs when it is inappropriate.
  • Can’t participate in leisure activities that require being quiet.
  • Appears to have a lot of energy and is always on the go.
  • Talks excessively.
  • Blurts out answers or statements before a person finishes speaking.
  • Struggles with waiting their turn.
  • Interrupts others engaged in conversations or activities.

ADHD symptoms must also have been present before age 12, interfere with daily functioning, appear in two or more settings, and cannot be due to another mental or physical condition.

Severity of Symptoms

Symptom severity will vary from person to person. Some people may have severe symptoms, while others have mild or moderate reactions. Mild symptoms occur occasionally and don’t make it too hard to function and complete daily routines.

Moderate ADHD symptoms occur more often than mild symptoms, but not enough to completely hinder daily functioning. Severe ADHD is associated with having numerous symptoms or having a few symptoms that are so severe you can’t complete work or academic, personal, or social obligations. 

When someone cannot function effectively in their daily routines due to the inability to pay attention or being hyperactive and impulsive, they should seek help from a psychiatrist to see if they meet the criteria for ADHD. There are no brain scans or blood tests for diagnosing the disorder, but mental health treatment professionals spend many years learning the symptoms and treatments.

What Are Co-Occurring Disorders?

When someone is diagnosed with co-occurring disorders, they have ADHD and another illness simultaneously. Some may have symptoms of ADHD and addiction, ADHD and bipolar disorder, or ADHD and an eating disorder.

Because mood issues like depression and anxiety can affect concentration, those are usually treated before ADHD. After the mood issue has been adequately addressed, we turn our attention to any remaining concentration issues, which we call ADHD.

Reports claim 80% of people with ADHD have at least one other psychiatric disorder.

Common ADHD Co-Occurring Disorders

CHADD’s National Resource on ADHD research shows how many individuals have a co-existing disorder with ADHD:

Substance Use Disorder

One in ten people with ADHD is said to have a co-existing substance use disorder with alcohol, prescription drugs, illicit drugs, or a combination of the three. Symptoms of a substance use disorder may enhance or counteract ADHD symptoms. 

Sleep Disorders

Half of all people with ADHD have trouble falling asleep, staying asleep, or being sleepy during the day. Lack of sleep can make ADHD symptoms worse, especially with concentration, completing tasks, and understanding directions.


One in five people with ADHD also have anxiety. Symptoms increase their feelings of restlessness and being on edge. They experience more stress and poor sleep.

Bipolar Disorder

Bipolar disorder affects one out of five people with ADHD. On top of ADHD symptoms, a person may experience mild, moderate, or extreme mood swings between depression and mania.


One out of ten people with ADHD also have depression. Symptoms of depression include feeling sadness, guilt, or hopelessness most of the day, having suicidal thoughts, losing interest in activities they once enjoyed, and isolating from friends and family.

Oppositional Defiant Disorder

Oppositional defiant disorder (ODD) is present in half of the individuals with ADHD. Some of the symptoms of ODD overlap with ADHD, even though they are two separate disorders. ODD is diagnosed when someone has behaviors that are aggressive and argumentative. They typically don’t think they should have to follow rules. They blame others for their mistakes, get overly angry with someone they feel has wronged them, and often want revenge.

Conduct Disorder

One in four people with conduct disorder has ADHD. Conduct disorder symptoms include outward aggression towards others and deviant behaviors. Examples include lying, stealing, hitting, fighting, and truancy.

ADHD and Co-Occurring Disorders Are Treatable

The first step in the treatment process is to diagnose your symptoms accurately. A psychiatrist can comprehensively assess your physical and psychological health to determine the root cause of your symptoms.

A treatment plan is created to treat your symptoms, which may include medication, behavioral therapies, support groups, and alternative treatments.

If you think you may have ADHD and a co-occurring disorder or have questions, call the Mental Health Center