Discuss the psychological and physiological acute effects of marijuana.

Question

What will be an ideal response?

Answer 1

Immediate physiological effects after smoking marijuana are relatively minor. It has been estimated that a human would need to ingest a dose of marijuana that was from twenty thousand to forty thousand times the effective dose before death would occur. Nonetheless, there is a dose-related increase in heart rate during early stages of marijuana ingestion, up to 160 beats per minute when dose levels are high. 
Blood pressure either increases, remains the same, or decreases, depending primarily on whether the individual is standing, sitting, or lying down. A dilation of blood vessels on the cornea resulting in bloodshot eyes peaks in about an hour after smoking a joint. Frequently there is a drying of the mouth and an urge to drink. Other physiological reactions are inconsistent, and at least part of the inconsistency can be attributed to cultural and interpersonal influences. For example, the observation that marijuana smoking makes you feel extremely hungry and crave especially sweet things to eat (often referred to as "having the munchies") generally holds true in studies of North Americans but not for Jamaicans, who consider marijuana an appetite suppressant.
Americans often report enhanced sexual responses following marijuana use, whereas in India marijuana is considered a sexual depressant. These reactions, being subjective in nature, can very well be slanted in one direction or the other by the mind-set (expectations) of the marijuana smoker going into the experience. A good example is the effect on sexual responses. Although expectations undoubtedly play a prominent role here, we should be aware of the possibility that varying effects also may be due to differences in the THC concentration of the marijuana being smoked. Studies of male marijuana smokers have shown that low-dose marijuana tends to enhance sexual desire, whereas high-dose marijuana tends to depress it, even to the point of impotence. It is quite possible that the enhancement results from a brief rise in the male sex hormone, testosterone, and that the depression results from a rebound effect that lowers testosterone below normal levels. 
The THC concentration in India is higher than that in North America. As a result, we would expect different effects on sexual reactivity. The same argument could be made with respect to the differences in marijuana's effect on appetite. In 2008, approximately 374,000 drug-related emergency department (ED) visits in the DAWN statistics (see Chapter 2) involved marijuana, making it the second-highest category behind cocaine. In about one fourth of these cases, marijuana was the sole drug present in the patient's system at the time. In general, marijuana related emergency department incidents have risen substantially in recent years, with an increase of 33 percent from 2004 to 2008. It is likely that a higher THC concentration has contributed to this increase.
Acute Psychological and Behavioral Effects
It is likely that a first-time smoker will feel no discernible effects at all. It takes some practice to
be able to inhale deeply and keep the smoke in the lungs long enough (up to forty seconds) for a minimal level of THC, particularly in low-quality marijuana, to take effect. Novices often have to be instructed to focus on some aspect of the intoxicated state to start to feel intoxicated, but the psychological reactions, once they do occur, are fairly predictable. The marijuana high, as the name implies, is a feeling of euphoria and well-being. Marijuana smokers typically report an increased awareness of their surroundings, as well as a sharpened sense of sight and sound.
They often feel that everything is suddenly very funny, and even the most innocent comments or events can set off uproarious laughter. Usually mundane ideas can seem filled with profound implications, and the individual may feel that his or her creativity has been increased. As with LSD, however, no objective evidence shows that creativity is enhanced by marijuana. Time seems to pass more slowly while a person is under the influence of marijuana, and events appear to be elongated in duration.
Finally, marijuana smokers frequently report that they feel sleepy and sometimes dreamy. Relatively low THC concentrations in a marijuana joint are not sufficient to be particularly sleep inducing, though stronger cannabis preparations with higher THC can have strong sleep-inducing effects, particularly when combined with alcohol. At the same time, marijuana produces significant deficits in behavior. The major deficit is a decline in the ability to carry out tasks that involve attention and memory. Speech becomes increasingly fragmented and disjointed; individuals often forget what they, or others, have just said. The problem is that marijuana typically causes such a rush of distracting ideas to come to mind that it is difficult to concentrate on new information coming in. By virtue of a diminished focus of concentration, the performance of both short-term and long-term memory tasks is impaired. In general, these difficulties increase in magnitude as a direct function of the level of THC in the marijuana.
The decline in sensorimotor performance will persist well after the point at which the marijuana smoker no longer feels high, when there has been chronic heavy marijuana use. Significant impairments in attention and memory tasks have been demonstrated among heavy marijuana users (daily smokers) twenty-four hours after they last used the drug. Therefore, we have to recognize the possibility that some important aspects of behavior can be impaired following marijuana smoking, even when an individual is not aware of it. This effect is likely due to the very slow rate at which marijuana is eliminated from the body. Acute emotional problems as a result of smoking marijuana are rare among Americans, who typically are exposed to relatively low THC concentrations, though some distortion of body image, paranoia, and anxiety may occur. It is possible that marijuana smoking among individuals predisposed toward or recovering from a psychosis may trigger psychotic behavior.