Final answer:
Bipolar disorder is associated with decreased prefrontal cortex activity during depressive phases and increased anterior limbic network activity during manic phases, reflecting the characteristic mood swings.
Step-by-step explanation:
In bipolar diseases, there are decreases in prefrontal activation during the depressive phase and increases in activation in the anterior limbic network during the manic phase. This reflects the neural basis of the mood swings that characterize bipolar disorder, where the prefrontal cortex is responsible for cognitive functions such as decision making and the anterior limbic network is involved in emotional regulation. Several studies have indicated different brain activity patterns in depressive and manic episodes.
For example, the amygdala, which is part of this limbic network, has been shown to have heightened activity during manic periods which corresponds to the higher emotional arousal observed in such phases. Conversely, reduced activity in the prefrontal cortex during depressive episodes relates to impaired executive functioning and emotional regulation.