If there are other challenges or difficulties to understand, then assessing ADHD can be more complex. It's important to understand everything that may be playing a part in keeping someone from meeting their potential or understanding their uniqueness.

According to research by CHADD (Children and Adults with ADHD) 14 percent of children with ADHD have co-occurring depression, and 30 percent also have anxiety. Of adults with ADHD, about 47 percent also have depression, and 53 percent have anxiety.

Co-Occurring Mental Health Conditions Are Common - CHADD

The New Zealand ADHD Clinical Principles Framework provides expectations for assessment, including considering other diagnoses with similar symptoms and co-occurring conditions.

New Zealand Clinical Principles Framework for Attention Deficit Hyperactivity Disorder | Ministry of Health NZ

Other conditions that can co-exist with ADHD

Here are some conditions that can exist alongside ADHD. Please note: these are the conditions we are most aware of. It is by no means an exhaustive list. 

Alcohol and substance use

Untreated ADHD can increase the risk of alcohol and substance use issues as a form of self-medication. For more information and support visit: 

Untreated ADHD leading to addiction and drug harm - NZ Drug Foundation

Alcohol and drugs support | Healthify

Anxiety disorders

Anxiety and ADHD can be tightly interwoven. That's why it's important to work with a clinician who understands the full picture. You can find more about anxiety disorders here: Anxiety | Mental Health Foundation

And read about the connection with ADHD here: 

Anxiety and ADHD can overlap – here’s how to untangle these widespread mental health disorders

Auditory Processing Disorder (APD)

ADHD and Auditory Processing Disorder can be mistaken for each other, and both can be put down to simply 'not listening.' Find out more about about APD and where to find support here: 

Auditory Processing Disorder (APD) » New Zealand Audiological Society

Assistive technology support for auditory processing disorder - Ministry of Education

Autism 

ADHD and autism can combine to create a condition known as AuDHD. WIth the support of Autism New Zealand we have created an AuDHD resource page, which you can find here: 

ADHD NZ - ADHD and autism

For information on autism itself see: 

Autism | Mental Health Foundation

Definitions - Autism NZ

Bipolar disorder 

ADHD and bipolar disorder can overlap or be mistaken for each other. To find out more about bipolar visit: 

Bipolar disorder | Mental Health Foundation

Conduct disorder

In some cases children with ADHD may also develop a conduct disorder. You can find out more here: 

Children with conduct disorder | RANZCP

ADHD and Disruptive Behavior Disorders - CHADD

Depression 

Depression often stems from the chronic stress, low self-esteem, and daily life overwhelm associated with untreated ADHD. Find out more here: 

Depression | Mental Health Foundation

Depression and ADHD: How They’re Linked

Depression and young people

Depression can look different in young people than it does in adults. For more information on this visit: 

Depression - Youth | Mental Health Foundation

Dyscalculia

Dyscalculia is a math learning disability that frequently co-occurrs with ADHD. You can find out more about it here: 

Dyscalculia - SPELD NZ

Dyscalculia

Dyslexia

Dyslexia is a neurodevelopmental learning difference that affects reading, spelling and writing. Approximately 30% of people with ADHD also have dyslexia. To find out more visit: 

Dyslexia Foundation NZ | Knowledge Hub - Support for Dyslexia in NZ

Dyslexia - SPELD NZ

Dyspraxia 

Dysproxia is a developmental coordination disorder. Research estimates between 30 to 50% of people with ADHD have it as a co-occurring condition. For more information visit: 

Dyspraxia

Dyspraxia - SPELD NZ

Eating disorders

Studies show that people with ADHD are more than three times likely than the general population to develop an eating disorder. Find out more here: 

What Role Does ADHD Play in Eating Disorder Treatment? | Psychology Today New Zealand

Eating disorders | Mental Health Foundation

EDANZ | Eating Disorder Association of New Zealand 

Hypermobility 

Research indicates a strong connection between ADHD and joint hypermobility and conditions such as Ehlers-Danlos Syndrome (hEDS) or Hypermobility Spectrum Disorder (HSD). For more information see: 

Hypermobility 101 Series – Ehlers-Danlos Syndromes Aotearoa New Zealand

EDS Info – Ehlers-Danlos Syndromes Aotearoa New Zealand

ADHD and hypermobility: Links, effects, and exercises

Learning difficulties

While ADHD is a neurodevelopmental disorder rather than a specific learning disability, it frequently co-occurs with other learning challenges such as dyslexia and dyspraxia. To find out more about learning difficulties visit: 

Learning difficulties | Healthify

ADHD - Attention Deficit Hyperactivity Disorder - SPELD NZ

Oppositional Defiant Disorder (ODD)

Oppositional Defiant Disorder frequently co-occurrs with ADHD. To find out more about ODD visit: 

Oppositional Defiant Disorder | Autism New Zealand (PDF)

The ADHD ODD Behavioral Link in Children

Obsessive Compulsive Disorder (OCD) 

Neurodivergent people, particularly those with ADHD and autism can have higher rates of OCD. Find out more about OCD here: 

Obsessive compulsive disorder | Mental Health Foundation

Obsessive compulsive disorder (OCD) support | Healthify

Tourette Syndrome and tics

Tourette Syndrome, tics, and ADHD frequently co-occur. To find out more visit: 

What is TS — Tourette's Association of New Zealand

ADHD and Tics or Tourette Syndrome - CHADD

Associated physical conditions

There are number of physical issues that can be assocated with ADHD. These include: 

• digestive upset - reflux and/or irritable bowl syndrome
• allergies, eczema, and asthma
• nail biting, skin picking
• poor temperature sense and control
• muscle or stomach pains
• migraines or headaches
• food or sugar cravings - difficulty regulating appetite 
• ear troubles - grommet insertions, infections, glue ear
• eye troubles - including visual tracking, dark circles, puffiness and allergic rhinitis. 
• thyroid issues
• sleep disturbance including Restless Leg Syndrome, insomnia and sleep apnea. 

Developmental challenges 

Children with ADHD may experience developmental challenges from messy handwriting to specific learning disabilities in reading, writing, or math. 

They may also be diagnosed with Autism Spectrum Disorder (ASD), anxiety, or Oppositional Defiant Disorder (ODD). Dyspraxia, or Developmental Coordination Disorder (DCD) may also be an issue. This can present as clumsiness, poor balance, movement, coordination and core muscle control, poor ball skills, and mixed left-right dominance