The Link Between Tic Disorders and ADHD

Tics are characterized by repeated, sudden, jerky, involuntary movements of one’s face, shoulders, hands, legs or other body parts. Movements may include eye blinking, shoulder shrugging, neck twisting, facial grimacing, sticking out tongue, flaring nostrils, clenching fists, jerking arms, kicking, and curling toes.

Tics can also be vocal. These vocal tics may include throat-clearing, sniffing or snorting, grunting, dry coughs, clicking, hissing, barking, or even words or phrases.

These movements and/or vocalizations may occur frequently throughout the day or they may occur only occasionally. They tend to increase under excitement, physical or social stress, anxiety if the individual is very tired, or very idle. Some medications are also believed to exacerbate tics. Tics occur less often when a person is relaxed and calm. Tics do not occur during sleep.

Treatment for an individual with a tic disorder may include medication to help control the symptoms.

The older "typical" neuroleptics such as pimozide and Haldol are often used to reduce tics, in addition to the newer "atypical" neuroleptics/antipsychotics such as risperidone. Clonidine and guanfacine, types of anti-hypertensive agents, may also be used because of their reduced side effects.

The most common tic disorder is called provisional tic disorder (PTD), which was previously known as transient tic disorder, which is common in children. Tics which last one year or more are called persistent tics, which are also known as chronic motor of vocal tic disorders (CMVTD).

Tics occur in about 20% of school-age children. Approximately 1 in 5 children age 6-17 years old may develop a tic, but may sometimes start as early as 2 years of age. Tic disorders do appear to have a genetic link, as they tend to run in families, and have also been linked to environmental factors.

Chronic tic disorders affect about one percent of children and may indicate a more serious disorder called Tourette Syndrome (TS).

Tourette syndrome is a genetic, neurological disorder whose primary manifestations are the presence of motor and vocal tics. Tourettes is commonly associated with ADHD, obsessive-compulsive disorder, behavior problems, and learning disabilities.

The National Institute of Neurological Disorders and Stroke report that approximately 200,000 Americans have the most severe form of Tourettes, while as many as one in 100 display the milder symptoms such as a chronic motor or vocal tics or provisional tics of childhood.

Though Tourettes is a lifelong condition, symptoms tend to peak during the early teenage years with improvement in later adolescence and adulthood. Tourettes affects males approximately three to four times more often than females.

A 2016 study found that 35–90% of children with tics also had ADHD. Research has found that chronic tic disorders, Tourette syndrome, and obsessive-compulsive disorder may have similar neurological origins, and an individual with any of these conditions is also quite likely to have ADHD. In children who develop tic disorders and ADHD, the ADHD usually develops 2 to 3 years before the tics.

There has been some controversy over whether stimulants, the most common form of medication therapy for ADHD, worsen or even causes tics. Studies indicate that most children with co-occurring tics and ADHD do not experience an increase in tic severity while on low to moderate doses of stimulants.

However, there does appear to be a small proportion of children for whom this is a problem. It is not clear if the stimulants actually cause the tic or if the stimulants trigger tics that were already pre-existing, but not yet obvious. It is also possible that tic disorders may look similar to ADHD in their early stages. So the tic would have developed whether or not the child had been treated with stimulants.

If your ADHD child develops tics, report it to your child’s doctor. Together you will weigh the risks and potential benefits of medication, as well as explore alternative medicines to stimulants.