Teenage
years are a crucial period in an individual’s life as they are not fully
developed. Really it is a
moment of heightened drug use due to many reasons but partially sensation
seeking and unique in vulnerability. Many psychological and neurological observations show
that there is a link between the drug cannabis and negative impact on adolescents’
mind and behaviour.  In particular,
teenagers aged 15 or below are more susceptible to developing symptoms related
to neuropsychological impairment. A study conducted by Fontes, et al. (2011) on 104 cannabis users,
predicted participants who had early age (15 or below) exposure to cannabis
will perform poorly in the given tasks.

The methods employed by Fontes et al.
(2011) looked to examine n=104 participants in three groups. The groups
consisted of an early onset cohort that were aged 15 and below. The second
group were a late onset cannabis use group that initiated use over the age of
15. Additionally, a control group was recruited for the research, which had not used cannabis in the last 3 months and no
more than 5 times in their lives. The control group allowed the researchers to make comparisons to
determine if the age at which cannabis exposure happened, has an effect on
their mental functions. A battery of tests were employed to
look at executive functioning. The tests consisted of a Frontal Assessment Battery-
FAB (to assess the control of cognitive processes); a vocabulary and block
design (WAIS-R) for IQ; a Wisconsin card sort (to test peoples’ capacity in understanding general
ideas); and a Stroop test scale (to measure selective attention and the ability to
think about different concepts at the same time).

Overall there was no significant
differences between early and late onset groups. They did not vary drastically
in their average IQ scores, along with the other tests. However, there were
significant differences found between early onset and control participants on
all the tests. The most significant difference in scores between the two groups was found in the Wisconsin test. The
early onset participants had not only left the test unfinished, but they also
made obvious mistakes (on average 3.64 more than the control group), which
showed their incapability in understanding general ideas, planning, reasoning,
and problem solving. The Stroop test results were also found to be different as
the early onset scored high (18.20) compared to the control group (15.64), an
indication that early exposure to cannabis results in an inability to process
different concepts. The FAB test found similar results, as the early onset
group performed worse (15.85) in comparison with the control group (17.09). The
result indicated that cannabis use during early adolescence negatively impacted
the participants thought process.    

In conclusion, the
results imply that the hypothesis is correct, as the early onsets yielded
unsatisfactory results compared to the other groups. This signifies that cannabis
use from early adolescence (aged 15 or below) has a damaging effect on the
brain development, due to cognitive impairment. Previous findings from similar
studies in the past are comparable, displaying great difference in executive
functioning depending on the age at which drug cannabis was exposed.