Pattern recognition analyses of brain activation elicited by happy and neutral faces in unipolar and bipolar depression
Bipolar Disorders, 05/30/2012
Mourao–Miranda J et al. – The results indicate that patterns of whole–brain neural activity to intense happy faces were significantly less distinct from those for neutral faces in bipolar I disorder than in either healthy comparison subjects or unipolar depression. These findings indicate that pattern recognition approaches can be used to identify abnormal brain activity patterns in patient populations and have promising clinical utility as techniques that can help to discriminate between patients with different psychiatric illnesses.Methods
- The authors used a novel analytic framework to examine the extent to which unipolar and bipolar depressed individuals differed on discrimination between patterns of neural activity for happy and neutral faces.
- The authors used data from 18 currently depressed individuals with bipolar I disorder (BD) and 18 currently depressed individuals with recurrent unipolar depression (UD), matched on depression severity, age, and illness duration, and 18 age- and gender ratio-matched healthy comparison subjects (HC).
- fMRI data were analyzed using a general linear model and Gaussian process classifiers.
- The accuracy for discriminating between patterns of neural activity for happy versus neutral faces overall was lower in both patient groups relative to HC.
- The predictive probabilities for intense and mild happy faces were higher in HC than in BD, and for mild happy faces were higher in HC than UD (all p < 0.001).
- Interestingly, the predictive probability for intense happy faces was significantly higher in UD than BD (p = 0.03).