Worse lung function seen for CF children with ADHD symptoms
Study highlights need for early ADHD diagnosis in patients of all ages
Children with cystic fibrosis (CF) who also have symptoms of attention-deficit/hyperactivity disorder (ADHD) may experience worse lung function, according to a new study from Israel and Spain.
But the study also spotlighted a potentially far-reaching impact from ADHD on CF symptoms and care for children and adults who may have both disorders.
Among children, the researchers also observed that inattention was linked to higher white blood cell counts, which could mean more inflammation. In adults with CF, symptoms of ADHD were associated with longer treatment with oral antibiotics for lung infections. Regular use of antibiotics by CF patients has been seen to lead to hypersensitivity, or allergic, reactions, and can result in side effects such as fungal infections and diarrhea.
“These results highlight the need for an early diagnosis of ADHD in [people with CF], which have the potential to improve their ability to deal with the burden of their disease and consequently their quality of life,” the researchers wrote.
The study, “The association between Attention-Deficit-Hyperactivity-Disorder (ADHD) symptoms and disease severity in people with Cystic Fibrosis (pwCF),” was published in the Journal of Cystic Fibrosis.
Worse CF symptoms seen in children and adults with signs of ADHD
People with ADHD experience symptoms that fall into a pattern of being inattentive, which refers to having trouble concentrating and focusing, and/or being hyperactive and impulsive.
These symptoms persist over time and can make everyday activities, such as taking medications on time and sticking to a treatment plan — called treatment adherence — more challenging than they are for most other people. ADHD can continue into adulthood, though its symptoms may be less severe in older patients.
Here, the researchers already knew that ADHD appears to occur more often in people with CF than in the general population, and that its presence may be linked to a poorer quality of life.
Now, they set out to determine whether ADHD may make cystic fibrosis symptoms more severe by looking at data from children and adults recruited from three CF centers in Israel and Spain.
The study included 143 people with CF, with ages ranging from 7 to 68. More than half (54.6%) had a chronic (long-lasting) infection with Pseudomonas aeruginosa, which is the most common cause of lung infection in people with CF.
Among these patients, a measure of lung function known as percent predicted forced expiratory volume in one second (FEV1%) was 77.6%. FEV values higher than 80% of the predicted average value are considered normal.
In the prior year, these individuals had experienced up to five mild pulmonary exacerbations, which are episodes of worsening lung symptoms. The number of severe pulmonary exacerbations ranged from zero to five, with a median of one.
All of the patients completed the ADHD Rating Scale, a test that scores ADHD-related symptoms, and MOXO-CPT, a gamified continuous performance test that can measure a person’s sustained and selective attention among distracting stimuli.
According to the results of the MOXO-CPT, 23 people with CF in the study — 16.1% in all — tested positive for ADHD. This proportion was higher than the global estimates of ADHD in children and adults, which range from 2.5% to about 7%.
In children with CF, more severe ADHD-related symptoms, measured using the ADHD Rating Scale, were linked to lower FEV1% or worse lung function.
More omission errors in the MOXO-CPT, which occur when a response is not given when it should due to inattention, were linked to higher white blood cell counts. White blood cells are part of the immune system and can drive inflammation in people with CF.
In adults with CF, more omission errors were linked to more days of treatment with oral antibiotics in the year prior to the study. People in the study had taken oral antibiotics for a median 30 days, and some for up to one year.
The results of the current study show an association between CF disease severity parameters and ADHD symptoms.
Fewer incorrect answers in children and faster responses in adults with CF were linked to higher body mass index, a measure of body fat based on height and weight.
While people in the study did not receive a definite diagnosis of ADHD, and adherence to a treatment plan was not determined, the results highlight a need for more research about ADHD and its link to CF.
“The results of the current study show an association between CF disease severity parameters and ADHD symptoms,” the researchers concluded.