Impaired volitional saccade control: first evidence for a new candidate endophenotype in obsessive-compulsive disorder.
Recent research suggests that patients with obsessive-compulsive disorder (OCD) have deficits in the volitional control of saccades. Specific evidence comes from increased latencies of saccadic eye movements when they were volitionally executed but not when they were visually guided. The present study sought to test whether this deviance represents a cognitive endophenotype. To this end, first-degree relatives of OCD patients as genetic risk carriers were compared with OCD patients and healthy controls without a family history of OCD. Furthermore, as volitional response generation comprises selection and initiation of the required response, the study also sought to specify the cognitive mechanisms underlying impaired volitional response generation. Twenty-two unaffected first-degree relatives of OCD patients, 22 unmedicated OCD patients, and 22 healthy comparison subjects performed two types of volitional saccade tasks measuring response selection or only response initiation, respectively. Visually guided saccades were used as a control condition. Our results showed that unaffected first-degree relatives and OCD patients were significantly slowed compared to healthy comparison subjects in volitional response selection. Patients and relatives did not differ from each other. There was no group difference in the visually guided control condition. Taken together, the study provides first evidence that dysfunctional volitional response selection is a candidate endophenotype for OCD.
Institut für Psychologie, Humboldt-Universität zu Berlin, Rudower Chaussee 18, 12489 Berlin, Germany. kloftliv@cms.hu-berlin.de
Lisa
L
Kloft
Benedikt
B
Reuter
Anja
A
Riesel
Norbert
N
Kathmann
D000328:Adult; D000704:Analysis of Variance; D002755:Choice Behavior / Q000502:physiology; D003463:Cues; D058068:Endophenotypes; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D015835:Ocular Motility Disorders / Q000209:etiology*; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*; D011795:Surveys and Questionnaires