Self injurious behaviour in Tourette syndrome: correlates with impulsivity and impulse control.
BACKGROUND
Self injurious behaviour (SIB), the deliberate, repetitive infliction of self harm, is present in a wide variety of neuropsychiatric disorders, including Tourette syndrome (TS). Although SIB occurs in up to 60% of individuals with TS, and can cause significant clinical impairment and distress, little is known about its aetiology.


OBJECTIVE
This study examined the relationship between SIB and other behavioural features that commonly co-occur with TS in nearly 300 subjects with TS participating in three genetic studies. SIB, obsessions, compulsions, tic severity, attention deficit hyperactivity disorder related impulsivity, risk taking behaviours, and rages were systematically assessed in all subjects.


METHODS
Using logistic regression, a best fit model was determined for both mild to moderate SIB and severe SIB.


RESULTS
Mild/moderate SIB in TS was correlated with the presence of obsessive and compulsive symptoms such as the presence of aggressive obsessions or violent or aggressive compulsions, and with the presence of obsessive-compulsive disorder and overall number of obsessions. Severe SIB in TS was correlated with variables related to affect or impulse dysregulation; in particular, with the presence of episodic rages and risk taking behaviours. Both mild/moderate and severe SIB were also correlated with tic severity.


CONCLUSIONS
This study suggests that mild/moderate and severe SIB in TS may represent different phenomena, which has implications for clinical management of these symptoms.
Mathews
C A
CA
Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093-0810, USA. camathews@ucsd.edu
Waller
J
J
Glidden
D
D
Lowe
T L
TL
Herrera
L D
LD
Budman
C L
CL
Erenberg
G
G
Naarden
A
A
Bruun
R D
RD
Freimer
N B
NB
Reus
V I
VI
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000523:psychology; D011889:Rage; D012309:Risk-Taking; D016728:Self-Injurious Behavior / Q000209:etiology* / Q000523:psychology*; D012720:Severity of Illness Index; D005879:Tourette Syndrome / Q000150:complications* / Q000523:psychology*