title: The healthy control subject in psychiatric research: impulsiveness and volunteer bias.
abstract: Exciting and demanding biomedical experiments may attract a specific subgroup of people as volunteers. In the present study of selection bias, subjects volunteering in a psychobiological study that included a potentially painful procedure (lumbar puncture) were compared with those who declined to participate, with regard to scores on personality scales administered during a previous investigation of the same subjects. Significant differences were found on the Eysenck Personality Questionnaire and Karolinska Scales of Personality Impulsiveness scale, suggesting an over-representation of impulsive individuals among the volunteers. If the specific subject of investigation has implications for the type of individual who will participate as a healthy volunteer in biomedical research, variation will be introduced, affecting the independent variable, and the conclusions that can be drawn from such research may be questionable.
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
authors.forename: J P
authors.initials: JP
authors.lastname: Gustavsson
authors.forename: M
authors.initials: M
authors.lastname: Asberg
authors.forename: D
authors.initials: D
authors.lastname: Schalling
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D007175:Impulsive Behavior / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D010551:Personality / Q000502:physiology; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics; D011603:Psychophysiology; D012106:Research / Q000706:statistics & numerical data*; D015983:Selection Bias; D012701:Serotonin / Q000502:physiology; D013129:Spinal Puncture / Q000523:psychology; D013334:Students / Q000523:psychology; D014838:Volunteers / Q000523:psychology*
chemical_list: D012701:Serotonin