OCD is associated with altered connectivity within the default mode network (DMN). This is a group of brain structures that are hypothesised to work together to perform specific functions. These include:
- Self-referential mental activity (Gusnard et al. 2001)
- Extracting episodic memory (Cabeza et al. 2002)
- Imagining the future (Schacter et al. 2007)
- Mind wandering (Mason et al. 2007)
The default mode network are highlighted in orange below.
Chinese researchers (Peng et al) found OCD patients exhibited reduced strength of the default network functional connectivity with the posterior cingulate cortex (PCC), and increased functional connectivity in the right inferior frontal lobe, insula, superior parietal cortex and superior temporal cortex.
A small study of people with OCD and siblings indicated a genetic basis for OCD symptoms via the actions of the default mode network.
Peng, Z., Xu, T., He, Q., Shi, C., Wei, Z., Miao, G., . . . Chan, R. (2014). Default network connectivity as a vulnerability marker for obsessive compulsive disorder. Psychological Medicine, 44(7), 1475-1484. doi:10.1017/S0033291713002250
By John Graner, Neuroimaging Department, National Intrepid Center of Excellence, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA. – http://www.frontiersin.org/Neurotrauma/10.3389/fneur.2013.00016/full, Public Domain, https://commons.wikimedia.org/w/index.php?curid=25872800