ABSTRACT
Neuroimaging research has emerged as a powerful force in shaping neurobiological models of psychiatric disorders. In this chapter, functional neuroimaging findings pertaining to mood and anxiety disorders are reviewed. We will review studies using functional magnetic resonance imaging (fMRI) as well as those using other functional neuroimaging techniques (e.g. positron emission tomography (PET) and single photon emission computed tomography (SPECT)) to delineate the neurocircuitry involved in mood and anxiety disorders. This review extends previous ones that we have written, together with our colleagues, on these and related topics.1-3
Contemporary models of mood disorders (unipolar depression and bipolar disorders), integrate a wide variety of findings from animal, human lesion, and postmortem studies, as well as structural and functional
neuroimaging studies. They emphasize that mood symptoms arise from disruptions in the interactions of widely distributed neural networks involved in emotional and cognitive processing.4-6 Symptoms of depression and mania are viewed as the result of disturbances in functions normally subserved by these networks, such as regulating emotions, attention and memory. In addition, these models assign some regional specificity in that dysfunction in certain portions of these networks are associated with cognitive, vegetative, or emotional features of depression (or mania). For example, Mayberg’s limbiccortical model of depression (Figure 7.1)5,6
involves three compartments, each responsible for some portion of the constellation of symptoms associated with depression. The dorsal compartment, including the dorsolateral prefrontal cortex (DLPFC) and dorsal anterior cingulate cortex (dACC), parietal lobe, and posterior cingulate, is postulated to be principally involved with attentional and
Figure 7.1 Mayberg’s model of depression.5 This involves three compartments: a dorsal compartment, including dorsolateral prefrontal cortex (dFr), inferior parietal cortex (inf Par), dorsal anterior cingulate (dCg), and posterior cingulate (pCg); a ventral compartment, including subgenual prefrontal cortex (Cg 25), ventral anterior insula (vIns), hippocampus (Hc), ventral frontal cortex (vFr), and hypothalamus (Hth); a rostral compartment, consisting of rostral anterior cingulate (rCg), midbrain pons (mb-p), and basal ganglia (BG); thalamus (Th); amygdala (Am). Numbers are Brodman designations.
