1. The effects of clonidine and hydrochlorothiazide on cardiovascular responses to mental stress were compared in adolescents with essential hypertension.2. Clonidine treatment has been associated with a decrease in diastolic pressure, heart rate, and norepinephrine in response to mental stress. In contrast, hydrochlorothiazide has led to numerous studies investigating the effects of caffeine on behavior and cardiovascular function. It is now important to clarify the mechanisms underlying these effects, as well as the main ones. The effects of stress on the cardiovascular system are not only stimulatory in nature, but also inhibitory in nature Engler and Engler, 1995. It can be postulated that stress causes activation of the autonomic nervous system and indirectly affects the function of the cardiovascular system Lazarus et al. 1963 Vrijkotte et al. 2000. Clonidine is an antihypertensive medication that lowers blood pressure and heart rate by relaxing the arteries and increasing blood supply to the heart. It has the following FDA-approved indications: Clonidine has multiple off-label uses, such as managing withdrawal symptoms from opioids, benzodiazepines, and alcohol and treating anxiety. The effects of alcohol on the heart are also complex. 3, 8, alcohol has been shown to directly inhibit cardiac muscle contractility in a dose-dependent manner. 18, negative. High blood pressure increases the workload on the heart and arteries. If this continues for a long time, the heart and arteries may not work properly. This can damage blood vessels in the brain, heart and kidneys, leading to stroke, heart failure or kidney failure. High blood pressure can also increase the risk of heart attack.