The short answer is that drug and alcohol abuse can be devastating to a person's health and academic performance.
To be more specific, getting intoxicated can have a negative impact on cognitive functions (concentration, memory, attention) for 48 hours. This means that if you get intoxicated on the last Friday of classes, your ability to study for finals on both Saturday and Sunday will be impaired; this in turn could have a negative impact on your ability to perform during your Monday exams.
The recovery from smoking pot is more complex, and is described below in more detail, along with a more detailed discussion of the impact of alcohol.
While by no means should this list be considered exhaustive, the following are some ways in which commonly used substances can be particular problems for college students. While several problems can accompany substance use and abuse, this list focuses on those drugs that impact two domains that are clearly barriers to academic success-anxiety and cognitive functioning.
There can be lingering cognitive deficits up to 48 hours after a night of drinking.
Heavy drinking by students can lead to positive blood alcohol levels the next day, affecting whether or not they even get up for class and, if they do, the quality of how information is processed and ultimately stored.
Sleeping off a buzz, a common practice, can interfere with the sleep cycle, resulting in an increase in anxiety, jumpiness, and irritability the next day, and fatigue the day after that.
"Although most people take for granted that alcohol impairs memory of events that occur during intoxication, alcohol consumption has further-reaching effects on memory and learning ability", a Duke University study suggests, "intoxication is produced by temporary impairment of brain receptors key in creating long-term memories in the hippocampus", said Jeff Georgi, a coordinator at the school's Alcohol and Addictions Program. "If you study for four hours...then go drinking, it affects this anchoring process," he told Duke's Chronicle. Alcohol also disrupts sleep, which interferes with long-term memory formation.
In addition, young adults seem to have more trouble than older adults learning while drinking, the study suggests. After study subjects drank two drinks in one hour, subjects aged 21 to 24 fared worse on a test of verbal and visual memory than subjects aged 25 to 29.
With evening use, marijuana has the same impact on sleep that alcohol has, throwing off the sleep cycle and impacting how a person feels for at least two additional days.
Marijuana suppresses neuronal activity in the hippocampus, resulting in problems with attention, memory, and concentration.
There is increasing evidence that there is an impact to motivation following marijuana use. This could be due to the effect of THC in the body blocking the passage of nutrients through cells, the neuronal suppression in the hippocampus, or the decrease in energy accompanying the fatigue that follows night time use.
Marijuana significantly increases heart rate, weakens the heart muscle, and affects blood pressure- the increase in heart rate can be a concern for someone already dealing with anxiety ( and particularly panic).
Source: Recruitment & Retention in Higher Education, November 2001 Vol. 15 No. 11
Written by Dr. Ginny Schwartz, Coordinator of Academic Support (2001-2008)