Tics - Causes of tics

The exact cause of tics is unknown, but they are thought to be related to the connections between certain areas of the brain involved in the production and control of movements.

As tics often run in families, with several family members being affected, they are thought to be related to your genes. However, other factors may also play a role.

Genetics

Your genes contain information (DNA) that controls characteristics such as the colour of your hair and eyes. It is possible that an inherited aspect of your genes is responsible for making you more susceptible to developing a tic, as it is well known that tics tend to run in families. Current research is trying to establish this genetic link through detailed family studies.

Medicines

Some medicines can generate an increase in tics. For example, methylphenidate and dexamfetamine, which are used to treat attention deficit hyperactivity disorder (ADHD).

You should discuss with your GP whether the benefit of the medicine outweighs the problem of the tics. It may be possible to reduce your dose or change your medicine if your tics are severe.

Other causes

Sometimes, a tic may be a symptom of another condition, such as:

• cerebral palsy – a condition caused by brain damage
• Huntington's disease – an inherited condition that damages some of the nerve cells in the brain
• any disease that affects an artery within the brain or that supplies blood to the brain (cerebrovascular disease)
• a head injury – although this is very rare

Tics can also occur as a result of taking recreational drugs, such as cocaine or amphetamines, or when you stop taking drugs (as a withdrawal symptom).