Psychology2016

566 CHAPTER 14

found in individuals with a history of neglect or physical, emotional, or sexual abuse,

in brain areas associated with mood, regulation of emotional behaviors, and attention

(Lim et al., 2014). One recent investigation across different psychological disorders

found variations in gray matter loss in several brain regions. Think back to the cov-

erage of different brain areas in Chapter Two. In addition to the reductions found in

the dorsal anterior cingulate and bilateral insular cortex across disorders, there was

greater loss in the hippocampus and amygdala in depressed individuals (Goodkind,

et al., 2015). Another investigation has found that baseline thickness of cortical gray

matter in the right medial orbitofrontal and right precentral areas of the frontal lobe,

the left anterior cingulate, and bilateral areas of insular cortex predicted future onset

of major depression in a group of 33 adolescent females (Foland-Ross et al., 2015). For

subcortical structures, researchers have found smaller volumes in the caudate, part of

the basal ganglia, for individuals with major depressive disorder (MDD) and bipolar

disorder (BD) as compared to controls, but individuals with MDD had greater vol-

ume in the ventral diencephalon, an area that includes the hypothalamus, than both

controls and individuals with BD (Sacchet et al., 2015). Functional neuroimaging has

also found dysfunction in many of these brain areas, with some being more active

and others less active as compared to controls, and to complicate it even further, the

direction of altered activity may be different in youth than in adults with depression

(Miller et al., 2015; Su et al., 2014).

Genes also play a part in these disorders. The fact that the more severe mood dis-

orders are not a reaction to some outside source of stress or anxiety but rather seem to

come from within the person’s own body, together with the tendency of mood disorders

to appear in genetically related individuals at a higher rate, suggests rather strongly that

inheritance may play a significant part in these disorders (Barondes, 1998; Farmer, 1996).

It is possible that some mood disorders share a common gene, but actual rates vary. For

example, genetic risks are higher in bipolar disorder as compared to unipolar depression

(Hyman & Cohen, 2013; McMahon et al., 2010). More than 65 percent of people with

bipolar disorder have at least one close relative with either bipolar disorder or major

depression (Craddock et al., 2005; National Institute of Mental Health Genetics Work-

group, 1998; Sullivan et al., 2000). Twin studies have shown that if one identical twin

has either major depression or bipolar disorder, the chances that the other twin will also

develop a mood disorder are about 40 to 70 percent (Muller-Oerlinghausen et al., 2002).

psychodynamic: depression is repressed anger originally aimed at parents

behavioral: depression is linked to learned helplessness

social cognitive: distorted thinking and negative, self-defeating thoughts

biological: variation in neurotransmitter systems (e.g., serotonin, norepinephrine,

major depressive disorder: deeply depressed mood; most commonly diagnosed mood disorder,

twice as common in women

bipolar disorders: experience of mood from normal to manic, possibly with episodes of depression,

or the experience of normal mood interrupted by episodes of depression and

hypomania

causes

Disorders of Mood

(involve a disturbance

in mood or emotion;

can be mild or severe)

Concept Map L.O. 14.9, 14.10

Interactive

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