ADHD News & Research

Study: ADHD, OCD, Tourette Syndrome Share Genetic Links

New research finds that 86 percent of people with Tourette Syndrome will be diagnosed with certain psychiatric disorders, most commonly ADHD or OCD.

March 10, 2015

In the largest study of its kind, research conducted over 16 years has affirmed that Tourette Syndrome (TS) often occurs alongside other psychiatric disorders. Most commonly, TS was diagnosed with ADHD, OCD, or both. Seventy-two percent of the group studied had TS with ADHD or OCD. Nearly one third of the group had all three conditions.

The study, conducted by the Tourette Syndrome Association International Consortium for Genetics (TSAICG), followed 1,300 TS patients from 1992 to 2008. Researchers interviewed participants, and reviewed diagnostic information from parents, siblings, and other relatives that did not have TS to examine how these conditions may be passed through family lines.

They found mood disorders, anxiety disorders, and disruptive behavior also prevalent among the patients studied, with 30 percent receiving one of these diagnoses with TS. Additionally, the study found that the comorbid conditions present at an earlier age than they do in the general population, sometimes even before the tic disorder is diagnosed. For example, anxiety and mood disorders show up in TS patients as young as five — 10 to 20 years before they are commonly seen in the population at large.

The researchers believe that the common concurrence of the disorders demonstrates a genetic relationship between ADHD, OCD, and TS.

The scientists hope that this new data will lead to earlier screening for these conditions, and more accurate diagnoses. The statistics on how commonly TS is diagnosed with ADHD and OCD could help physicians tease out which conditions are causing symptoms, and provide clues for additional screenings when they hit a dead end. This study lays bare the full spectrum of diagnostic possibilities that physicians should know when treating a patient with TS.