Which of the following statements is true of the chemical abnormalities in the bodies of people who suffer from bipolar disorder? a deficiency in the neurotransmitters dopamine and neuropeptide y (npy) leads to bipolar disorder in people who have experienced stressful situa­tions. high serotonin may be coupled with low levels of norepinephrine in the manic phase and with high levels in the depressed phase. in both the manic and depressed phases, serotonin levels are very high. thy­roid hormones are sometimes present in either abnor­mally high or low levels in people with bipolar disorder.

Thy­roid hormones are sometimes present in either abnor­mally high or low levels in people with bipolar disorder.

Explanation:

→depression is associated with low levels of thyroid hormone

→mood elevation is associated with high levels of thyroid hormone.

furthermore; reducing the  levels of high thyroid hormone  in the blood stream with lithium may mitigate  manic symptoms  in patients of bipolar disorder,

this buttress the point that fluctuations in thyroid hormones is a causative factor

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.