Final answer:
A client taking an SSRI with a MAOI is indeed at risk for a hypertensive crisis because of the potential for excessively high levels of serotonin that may lead to a dangerous condition called serotonin syndrome.
Step-by-step explanation:
The combination of a Selective Serotonin Reuptake Inhibitor (SSRI) and a Monoamine Oxidase Inhibitor (MAOI) can lead to a dangerous condition known as serotonin syndrome, which can cause a severe increase in blood pressure, among other symptoms. Therefore, the statement that a client who takes an SSRI with a MAOI is at risk for a hypertensive crisis is True. MAOIs and SSRIs both affect the levels of neurotransmitters, particularly serotonin, in the brain. Taking them together can result in an excessive amount of serotonin, leading to overstimulation of the central nervous system and cardiovascular system, with the potential for a life-threatening hypertensive crisis.