Letter to the Editor
Cannabinoids improve driving ability in a Tourette's patient
To the Editor:
For many patients diagnosed with a neuropsychiatric disorder, the
ability to drive a car plays a crucial part in their functional autonomy.
Surprisingly, there were no data available in a PubMed search performed
in March 2011 concerning Tourette's Syndrome and driving ability.
According to our knowledge, this is the first report on driving ability
in a drug-free Tourette's patient as well as after cannabinoid therapy.
“Mr. H. was a 42-year-old truck-driver, with Tourette's Syndrome
since the age of six. On the day of admittance to our hospital, he
exhibited coprolalia, multiple motor tics such as head, arm and leg
jerking, and repeatedly standing up and down. Mostly, he was
suffering from ruminating obsessive thoughts.
Diagnostic tests including lumbar puncture, magnetic resonance
imaging, and electroencephalography, did not produce any patholog-
ical findings. Neuropsychological testing was unremarkable with
regard to attention, memory and executive functions. IQ testing
revealed an average level of intelligence.
A review of the patient's medical history showed that all standard
treatments for tic disorders (dopamine-blocking agents, alpha-2-
agonists, clonazepam, and tetrabenazine) had proved ineffective.
Although there is still a lack of good controlled evidence to support
the use of cannabinoids in treating tics in people with Tourette's syn-
drome, experimental therapy with Δ
9
-tetrahydrocannabinol (THC) was
started. Within 2 weeks, the daily dose was raised to 15 mg. Tics
decreased significantly with scores on the Yale Global Tic Severity Scale
being reduced by 75% (Global Severity Score dropping from 89 to 22).
Since Mr. H.'s job required daily driving, he asked for a treatment
that would not affect his driving skills. Therefore, his driving ability
was assessed with computerized tests, according to the German
guidelines for road and traffic-safety, in an off/on-design. Both, in the
drug-free phase and during THC therapy, the criteria according to
German regulations were met in all functional domains investigated
(i.e. visual perception, capacity of reaction, concentration and stress-
tolerance). According to these criteria, a test has to be considered a
failure if a patient falls below the threshold of 1 standard deviation
below the mean in test parameters (percentage b16). In comparison
with the drug-free phase, there was a clear improvement in con-
centration (from percentage 39 to 58) and visual perception (from
percentage 44 to 72) during THC therapy.”
Tourette's syndrome is associated with motor and vocal tics and
a range of cognitive and behavioral features. To date, there is a
controversial debate whether the use of cannabinoids causes
cognitive impairment in healthy subjects. In Tourette's patients, it
has been shown that treatment with THC has caused neither acute nor
long-term cognitive deficits (Muller-Vahl et al., 2003). Our case study
indicates that there seem to be beneficial effects on psychomotor
functions related to driving performance under treatment with THC.
To highlight this topic, further studies on Tourette's driving under
THC-treatment are needed.
Full financial disclosure for the previous 12 months
No special financial support/grant was received in conjunction with this study.
Reference
Muller-Vahl, K.R., Prevedel, H., Theloe, K., Kolbe, H., Emrich, H.M., Schneider, U., 2003.
Treatment of Tourette syndrome with delta-9-tetrahydrocannabinol (delta 9-
THC): no influence on neuropsychological performance. Neuropsychopharmacol-
ogy 28 (2), 384–388 Feb.
Alexander Brunnauer
Department of Psychiatry and Psychotherapy,
Ludwig-Maximilians-University, Munich, Germany
Psychiatric Clinic, Inn-Salzach Hospital Wasserburg/Inn, Germany
Felix Maximilian Segmiller
Thomas Volkamer
Department of Psychiatry and Psychotherapy,
Ludwig-Maximilians-University, Munich, Germany
Gerd Laux
Psychiatric Clinic, Inn-Salzach Hospital Wasserburg/Inn, Germany
Norbert Müller
Sandra Dehning⁎
Department of Psychiatry and Psychotherapy,
Ludwig-Maximilians-University, Munich, Germany
⁎Corresponding author at: Ludwig-Maximilians-University,
Nußbaumstr. 7, 80336 Munich, Germany.
Tel.: +49 89 5160 3348; fax: +49 89 5160 5348.
E-mail address: sandra.dehning@med.uni-muenchen.de.
24 May 2011
Psychiatry Research 190 (2011) 382
0165-1781/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved.
doi:10.1016/j.psychres.2011.05.033
Contents lists available at ScienceDirect
Psychiatry Research
journal homepage: www.elsevier.com/locate/psychres
