ADHD and schizophrenia: What you need to know

ADHD and schizophrenia: What you need to know

Attention deficit hyperactivity disorder and schizophrenia are two distinct disorders that can significantly affect a person ‘s life. Although they have many similarities, they do share certain characteristics.

Therefore, some scientists have been looking into a potential link between them.

Attention deficiency hyperactivity disorder (ADHD ) is a chronic condition containing signs of behaviour, including inattention , hyperactivity, and impulsiveness.

This is a neurodevelopmental condition, which typically is diagnosed by age 12. While symptoms appear to improve with age, symptoms are still present in some people as adults.

ADHD is more common in males during childhood than in females, but in adulthood the incidence is comparatively so. Fewer girls may obtain a diagnosis because they display signs differently, which means caregivers or teachers can not identify them.

The Centers for Disease Control and Prevention ( CDC) reports that about 6.1 million children living in the U.S. were diagnosed with ADHD by 2016.

Schizophrenia is a long-term mental health disorder which affects a person’s way of thinking, feeling and acting. This includes psychosis and other symptoms, including attention loss.

Schizophrenia is far more prevalent in males than females. Symptoms typically begin between the ages of 16 and 30 but can occur during childhood.

According to the National Alliance on Mental Illness (NAMI), about 1 percent of individuals in the U.S. have schizophrenia.

ADHD and schizophrenia links

A lady in office thinking about her life
A lack of focus is common with ADHD and with schizophrenia.

Various research found some parallels and a possible connection between ADHD and schizophrenia.

The researchers results include the following:

  • People with schizophrenia often have symptoms of other psychiatric disorders, including ADHD, in early adolescence.
  • Children and teenagers with ADHD may be 4.3 times more likely to develop schizophrenia as adults than people without ADHD.
  • Close relatives of people with ADHD may be more likely than second-degree relatives to receive a diagnosis of schizophrenia, suggesting that it may have a genetic component.

A team of geneticists searching for ADHD in children and adult schizophrenia found evidence of a “small but significant shared genetic risk” in 2013.


It is not clear the exact causes of ADHD and schizophrenia, but a combination of genetic and environmental factors that increase the risk of both.

A person with different genetic traits that develop symptoms if they experience such causes, be it prior to birth or during childhood and adolescence.


Factors that may contribute to ADHD include:

  • Genetic features: ADHD can run in families.
  • Environmental factors: Exposure to toxic materials, including as a fetus, may increase the risk.
  • Developmental issues: Problems with the central nervous system at important stages of development may result in ADHD.


Factors that may increase a person’s likelihood of developing schizophrenia include:

  • Genetic features: Genetic factors appear to play a role. Having a close family member with schizophrenia may increase the risk.
  • Brain development: Research shows that some individuals with schizophrenia have subtle differences in their brain structure.
  • Neurotransmitters: An imbalance between dopamine and serotonin, the chemical messengers in the brain, may have a connection with schizophrenia. Drugs that alter the levels of these chemicals appear to relieve schizophrenia symptoms.
  • Pregnancy and birth complications: A low birth weight, premature labor, or insufficient oxygen during birth are more likely to have affected people with schizophrenia.

ADHD and schizophrenia

These disorders include changes in neurodevelopment, which can occur in families. Researchers, however, still do not know whether the same modifications are related to both conditions or to what extent these underlying features overlap.

Risk factors

ADHD and schizophrenia risk factors aren’t the same but can overlap. Many risk factors can affect a person before birth for both conditions, while others can take effect during childhood and adolescence.


Risk factors for ADHD include:

  • a family history of ADHD or another mental health disorder
  • exposure to certain substances while in the womb
  • a lack of specific nutrients, such as folate, zinc, magnesium, and polyunsaturated acids


There is growing evidence that some environmental factors can lead to problems with neurodevelopment which lead to schizophrenia.

Possible environmental factors include:

  • exposure to certain substances, such as cannabis or lead, before birth
  • nutritional deficits, including low levels of folic acid and iron
  • rubella or other maternal infections during pregnancy
  • maternal stress during pregnancy
  • infections during childhood and adolescence
  • deficiency in iron and vitamin D resulting in decreased choline during pregnancy
  • an increase in immune system activity due to inflammation or autoimmune disease
  • taking mind-altering drugs as teenagers or young adults

Several studies have indicated there may be a correlation between low birth weight and mental illness, including likely schizophrenia. They also acknowledged, however, that it needs more research to support this.

2011 review authors concluded:

“It seems highly likely that a significant number, if not the majority, of cases of schizophrenia may be accounted for by associations between environmental and genetic factors and by other mechanisms involving the subtle interplay between environments and genes.”

Researchers think the causes that can contribute to ADHD and schizophrenia overlap.

Genetic factors: A person who has a close relative with schizophrenia may have a greater risk of developing ADHD. Studies claim up to 80 percent of schizophrenia cases and 60 to 80 percent of ADHD cases will result from inheritance.

Changes in the underlying brain mechanisms: Other physiological causes are common to both.

Environmental influences: Exposure to common stimuli seems to raise the likelihood of both conditions before birth and during childhood.

Shared history: People with schizophrenia are more likely to have had a childhood diagnosis of ADHD.

Does ADHD medication lead to schizophrenia?

Many people who take stimulant drugs to alleviate ADHD symptoms tend to experience psychotic symptoms.

If using stimulants to treat ADHD raises the likelihood of schizophrenia or symptoms of schizophrenia-type, specifically psychosis, is uncertain however. Such signs may have occurred without the use of stimulant medications.

Psychostimulant drug use does tend to increase the risk of psychosis. Psychosis occurring at a younger age is more likely to be the result of psychostimulant substance use.

It is uncertain, however, whether psychosis is the result of taking the drugs or whether these people are still susceptible to psychosis.

Furthermore, the type of insanity encountered by people with ADHD appears to be different from that of people with schizophrenia as it includes brief mental changes rather than full hallucinations.


There are various signs of ADHD and schizophrenia but they converge in the area of inattention.


There are three different types of ADHD:

  • inattentive ADHD
  • hyperactive and impulsive ADHD
  • combined inattentive and hyperactive ADHD

Symptoms of inattentiveness include:

  • having a short attention span and getting easily distracted
  • making careless mistakes during activities
  • appearing not to listen
  • being unable to follow instructions and complete tasks
  • having problems with organizing tasks
  • being forgetful or frequently losing things
  • avoiding tasks that require mental effort

Symptoms of hyperactivity and impulsiveness include:

  • fidgeting constantly and being unable to sit still
  • being unable to engage quietly in leisure activities
  • lacking concentration
  • talking excessively
  • interrupting other people’s conversations or intruding on their activities
  • being restless
  • running excessively or climbing in inappropriate situations
  • acting without thinking
  • having little or no sense of danger

Not everyone who has ADHD will have hyperactivity as a symptom.


Physicians identify schizophrenia symptoms as either positive, negative or cognitive.

Positive symptoms include:

  • hallucinations
  • delusions, such as believing that the government is pursuing them
  • paranoid thoughts
  • agitated or excessive body movements
  • agitated or inappropriate behavior

Negative symptoms include:

  • social withdrawal
  • not caring about appearance and personal hygiene
  • reduced emotional expression
  • losing interest and motivation
  • trouble concentrating
  • changes in sleep habits
  • feeling unable to leave the house
  • a decrease in conversation and speaking

Cognitive symptoms include:

  • having confused or disorganized thoughts
  • an inability to understand information and make decisions
  • a lack of focus and attention
  • difficulty using learned information immediately

ADHD and schizophrenia

A man with low life esteem
People with both conditions may need help to overcome problems of inattention.

ADHD and schizophrenia may have symptoms in common.

Attention problems, for example , affect both people with ADHD and those with schizophrenia.

However, some studies have proposed that the form of inattention associated with ADHD may vary from that associated with schizophrenia and that the underlying neurological features may also vary.

Thought disorders and psychosis can also occur in schizophrenia as well as in ADHD. Schizophrenic people often undergo psychotic episodes, which can include hallucinations , delusions, and disturbed thoughts.

Psychosis is not characteristic of ADHD, but psychotic symptoms are reported by around 10 percent of individuals with this disorder. One theory is that such psychotic symptoms may be caused by the stimulant medications that physicians prescribe to treat ADHD.

Research has shown that most individuals whose genetic makeup puts them at high risk of schizophrenia can meet the criteria for an ADHD diagnosis.

Some people with ADHD may have hyperactivity but this is not a schizophrenia symptom.


Doctors treat ADHD and schizophrenia using different criteria.


There is no clear screening test for ADHD. A doctor will ask the patient about their history and symptoms of medication and then conduct a medical test to rule out any causes. Before make a diagnosis, the doctor must compare the symptoms to the guidelines for ADHD and the rating scales.

Diagnosis typically occurs in childhood, often before age 12.


A doctor will ask about the individual’s medical history and the symptoms they encounter. They should also ensure the effects are not caused by medication, alcohol abuse, or other medical condition.

Drug screening or imaging tests, such as an MRI or CT scan, may be done by the doctor.

When a psychiatrist or mental health professional suspects schizophrenia, a clinical examination may be done and the symptoms matched with medical criteria for schizophrenia.

According to the NAMI, schizophrenia typically occurs in people who are in their late adolescent years or early twenties, while the development appears to occur in women aged around 25–35.

TDA / Schizophrenia

In the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), a psychiatrist can diagnose both ADHD and schizophrenia by matching symptoms with those on a chart.

The DSM-5 classifies schizophrenia and ADHD as disorders which are entirely different. Schizophrenia is a psychiatric condition and ADHD is a disease of neurobehaviour.


There is no cure for ADHD or schizophrenia, but therapy can help relieve symptoms.


Treatment options include:

  • stimulant drugs to boost and balance brain chemical levels
  • nonstimulant medicines, which take longer to work than stimulants but can improve attention, focus, and impulsiveness
  • behavioral therapy to help people manage and change their behavior


Female Counselor
Counseling can help people with ADHD or schizophrenia, but each condition will need a different type of counseling and specific types of medication.

Treatment methods for treating schizophrenia symptoms include medications and psychosocial therapy.

Treatment may include:

Antipsychotic drugs: They are aimed at treating symptoms by regulating the levels of the chemical dopamine in the brain.

Psychosocial therapy: This combines psychotherapy and social interaction to people with schizophrenia to provide support, awareness and guidance.

Hospitalization: If a person’s symptoms are serious this might be appropriate.

Electroconvulsive therapy (ECT): The ECT can help people whose symptoms do not respond to medication.

Differences and similarities

There are various treatment options for ADHD, and schizophrenia. Physicians are trying to treat symptoms in both cases rather than cure the condition.

A doctor can prescribe stimulants for ADHD which increase the levels of dopamine in the brain. That type of medication could be causing paranoia in some individuals.

A doctor will prescribe antipsychotic drugs for schizophrenia which block the effect of dopamine.


ADHD and schizophrenia are separate disorders but they may occur together, and they may overlap. Several researchers claim there are other fundamental characteristics they share. But it remains unknown exactly how they respond to each other.

Of example, both situations require inattention, but it is not obvious if this is the same form of inattention, or if it has the same cause.

ADHD appears to start at a younger age, and symptoms often improve over time, but they may continue to grow into adulthood. Many individuals with ADHD tend to experience Schizophrenia symptoms, including psychosis.

In general, schizophrenia is a long term condition. Treatment may alleviate symptoms and enable many people to live a normal life, however if they don’t follow their treatment plan, relapse is probable. An individual with schizophrenia may have ADHD symptoms, too.

ADHD is slightly more severe than schizophrenia. Many individuals have ADHD, and schizophrenia rarely grows. There is no evidence of contributing one disease to the other.

The precise interconnection between the two conditions requires further