The neurobiological mechanism of tic disorder is explained by dysfunction in the basal ganglia-thalamus-cortex circuit. When dopamine, serotonin, and glutamate signaling become imbalanced in this circuit, the brain's ability to inhibit movement weakens, and unwanted movements occur. Genetic predisposition is significant — having a family history increases the risk — and tic disorders share a neurobiological basis with ADHD and obsessive-compulsive disorder. An autoimmune reaction following streptococcal infection (PANDAS) has also been identified as a pathway that triggers or worsens tics. Because the nervous system is still developing in childhood, symptoms often naturally remit as adulthood approaches.