Brief Answer:
see below answer

Detailed Answer:
Hi,

Welcome to HealthcareMagic .

The following are most common (in decreasing order) danger effects of smoking pot (mega amount) by your son
-reduced concentration power and memory and intelligence level
-dependency on the drug(addiction)
-cough and depression
-behaviour changes
-cause psychosis in previously mentally susceptible persons
-in susceptible persons precipitate schizophrenia and sucidal tendency

Individual response and side effects vary from person to person for same amount .

Smoking pot is also considered to cause some cancers but this is not true in all and not proved and also not common like
-lung cancer
-testis cancer

Hope I have been helpful.

Regards
Dr.Deepika Patil

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