Some of these young kids start trying different substances initially to fit in, but then after a while they start to develop a tolerance for these substances and experience withdrawal if they dont have enough substances in their system and eventually become dependent on having the effects of substance dependence. With tolerance comes the craving for additional substances to get high, this constant need for that feeling is polysubstance dependence.In the older generations, polysubstance dependence had been linked to additional considerations such as personality disorder, homelessness, bipolar disorder, major depressive disorder and so on. Medical care being so expensive and difficult to get long term has been linked to polysubstance dependence. Those who need psychological help sometimes use multiple substances as a type of self medication to help manage their mental illnesses. Comorbidity of mental disorders
For most of these disorders, in relation to polysubstance dependence, there is a vicious cycle that those with a dependence go through. First, Ingesting the substance creates a need for more, which creates a dopamine surge, which then creates pleasure. As the dopamine subsides, the pleasure adds to the emotional and physical pain and triggers stress transmitters, which in turn creates a craving, which must then be medicated, and thus the cycle begins again. However, the next time they use, more of the substance will need to be used to get to the same degree of intoxication .
The results of this study showed that the group of people with polysubstance and alcohol use performed poorly on the CVLT recall and recognition tests compared to the group of people who exclusively consumed excessive alcohol only, which implies that polysubstance use impaired the memory and learning in a different way than the effects of alcohol alone can explain. Length of abstinence matter
To examine whether abstinence for long periods of time helps people with polysubstance use recover their cognitive function, a group of researchers tested 207 polysubstance dependent men, of whom 73.4% were dependent on three or more substances. The researchers were interested in six areas of cognitive functioning, which included visual memory, verbal memory, knowledge of words, abstract reasoning, inhibition (interference), and attention. The study used the Benton Visual Retention Test (BVRT) for testing visual memory, the California Verbal Learning Test (CVLT) for verbal memory, the Wechsler Adult Intelligence Scale vocabulary portion for knowledge of words, the Booklet Category Test for abstract reasoning, the Stroop Neuropsychological Screening task for inhibition, and the Trail Making Test for attention. The results showed that neuropsychological ability did not improve with increases in the length of time abstinent. This suggests that polysubstance dependence leads to serious impairment which cannot be recovered much over the span of a year. Causes
Biological
There is data to support that some genes contribute to substance dependence.