Twin studies on OCD - Daniel S Van Grootheest et al

• Twin studies have supported strong heritability for OCD
• These types of studies have been around for about 80 years, combining evidence from case studies and laboratory testing
• Monozygotic/MZ twins may be strikingly concordant rate for OCD (80-87%)
• Compared with 47-50% concordance in Dizygotic/DZ twins
• Compared with 47-50% concordance in Dizygotic/DZ twins
• We can suggest from these findings that biology can be strongly associated with being an contributing factor in the susceptibility of OCD in twins
• Therefore, supporting the idea that increased genetic similarity = increased likelihood of OCD