The results of the tests who evaluated the executive

         The researchers at the end of thisstudy could affirm that their hypothesis it was correct. Exposure to   cannabis according with the age willinfluence a lot the healthy development of the brain. Like it was mention atthe beginning the maturation of the brain still happen until early 20’sdifferent parts in different times.

With the results of the tests who evaluatedthe executive functioning of the participants helped to understand theimplications of consumption of this substance before and after age of 15. TheAuthors didn’t find differences on executive functioning performance betweenlate-onset and non-users like they found in the early-onset. So, consumption ofcannabis before age 15 will impair the development of neurocognitive functioningand consequently will lead to a bad performance of executive functioning.Conclusion According with the tests resultsof IQ, vocabulary and block design, didn’t exist differences between the early-onset,late-onset and non-users.

Doing comparisons, the early-onset had 3.64 moreerrors than control group and they didn’t finished the all WCST. Also, on theStroop test they had a bad performance scoring (18.20) while the control grouponly had (15.

64). Finally, in FAB tests the late-onset scored (16.82), thenon-users scored (17.09) and the early-onset group had only (15.85).

The number of individual that participateon the study was 148 of which 104 was chronic cannabis users and 44 were non-users(control group), the group of 104 users of cannabis was divided by two thosewho started before age 15 (55 individuals) and those who started after that age(49 individuals).Results Finally, to do the analysisand comparisons of the neuropsychological measurements between the tree groupsearly-onset, later-onset and non-users   the Authors used t- test (ANOVA).·        Vocabulary and Block design, IQ (Wechsler AdultIntelligence Scale-Revised (WAIS-R)- ability of verbally express vocabulary,visuospatial and motor skills.

·        Frontal Assessment Battery (FAB) measure conceptualization,mental flexibility, decision making environmental autonomy.·        Wisconsin Card Sorting Test (Version 64) evaluatecapacity of planning, form abstract ideas, preservation, conceptualization.·        Stroop Test (Victoria Version) evaluates thespeed and capacity of inhibit an automatic reading response. All the individuals on the interviewday did an assessment psychosocial functioning, that measures medical historyan history of the substance use, (Urine analyses).

They did the followingneuropsychological battery tests:To this study They did a recruitmentof chronic cannabis users to participate on the treatment at the Substance Use DisorderProgram, Federal University of Sao Paulo. To be able to start treatment at UNIADall individuals had to do a interview and provide complete medical andpsychiatric history to determinate if they are eligible to participate or not. Thecriteria of selection were people between 18 to 55 years, male and female, withcannabis misuse or dependence, the person would be excluded if had   history of other DSM-IV disorders, currentuse of psychoactive medications, history of head trauma with loss consciousnessfor more than 5 min, intellectual disability or IQ below 80, vision or hearingproblems and abstinence was motivated but not mandatory. For this study theyalso recruited a control group (non-users), the criteria it was almost the samebut to them all the way around they couldn’t use any psychoactive substance, notuse cannabis at all in the last 3 months or no been expose to more than 5times. Although the participants sign a document accepting the terms andconditions of the study and these interviews took a day-long.

Method       The aim of this study is to doan analysis to executive functioning of people who used cannabis before age 15(early -onset group) compared with those who started after 15 (later-onset group)and control (non-users). The hypothesis is that the early-onset will performworse on cognitive tests evaluating executive functioning comparative with later-onsetand non-users.Consumption of cannabis/marijuanaduring adolescence can influence negatively neuromaturation and cognitivedevelopment. Even with weeks of abstinence, users of cannabis will show slowerpsychomotor speed, poorer complex attention and memory skills and degradedplanning/ sequencing abilities comparing with non-uses.According with the studies thoseproblems can occur because after birth the brain of the human been stilldeveloping, certain areas of the brain like prefrontal cortex will develop indifferent times and just rich maturation around early 20’s. So, the environmentwill influence a lot the good or bad development of the brain.

These previous studies showed thatbeing expose to cannabis can cause neuropsychological issues, even if theindividual does some weeks of abstinence. They have another finding that thissubstance can be more harmful to some individual than others, like people whois expose to neurotoxic substances before age of 15 have big possibilities ofdeveloping permanent neuropsychological deficits comparing with individual whostarted after age of 15. Adolescence is a reallyvulnerable phase to brain development and substance abuse can impair theneurocognition of the individual. Just some studies measured the differences incognitive performance from who started before age of 15 with those who startedlater.Introduction