what causes tourette's

Tourette’s does not have one single known cause; it develops from a mix of inherited genes and brain changes, with some environmental factors increasing risk in certain people. Scientists understand some of the patterns behind Tourette’s, but the full picture is still being researched.

What Tourette’s Is

Tourette’s syndrome is a neurological condition where the brain produces sudden, repeated movements or sounds called tics. It usually starts in childhood and often becomes milder in late teens or adulthood.

Main Causes: Genes and Brain

The strongest factor is genetics : Tourette’s tends to run in families and is 10–100 times more common in close relatives than in the general population. Multiple genes, including ones like SLITRK1, NRXN1, and CNTN6, are thought to affect how brain cells grow and connect, rather than a single “Tourette’s gene.”

Brain imaging and lab studies suggest tics come from changes in circuits linking the basal ganglia, frontal lobes, and cortex. These circuits use chemical messengers such as dopamine, serotonin, GABA, glutamate, histamine, and norepinephrine, and abnormal activity in these systems seems to make tics more likely.

Environmental and Risk Factors

Even with a genetic tendency, not everyone develops tics, which points to environmental influences. Research has linked higher risk to:

• Smoking or complications during pregnancy, severe stress or nausea in pregnancy, and low birthweight.

• Premature birth, especially when one twin is smaller, and low Apgar scores at birth.

• Brain injuries, infections like encephalitis, carbon monoxide poisoning, and some medications or drugs that can trigger acquired tics.

For a small minority (around 1 in 20), no obvious genetic factor is found, and their tics may be more strongly tied to these non-genetic risks.

Why It’s Still “Unknown”

Researchers describe the cause as “unknown” because Tourette’s is not explained by a single event or defect. Instead, it appears when:

• A person has a certain genetic makeup that affects brain circuits and neurotransmitters.
• Environmental factors before or after birth nudge those vulnerable circuits toward producing tics.

Modern studies continue to look for more genes, map out brain networks, and track how stress, infections, and other life events might interact with someone’s underlying risk.

TL;DR: Tourette’s happens when inherited differences in brain wiring and brain chemicals (especially in movement and control circuits) combine with certain life or pregnancy-related risk factors; there is no single known cause, just a complex mix of genes, brain changes, and environment.

Information gathered from public forums or data available on the internet and portrayed here.