Gupta warned that the short-term effects of marijuana included immediate and temporary changes in thoughts, perceptions and information processing.
Apart from short-term memory, heavy long-term marijuana use permanently impairs memory or other cognitive functions.
Experts warn that youngsters who smoke ganja lose their mental balance and resort to absurd reasoning to defend their addiction.
"Some say this is not a hard drug; others claim it is a plant product and so it is harmless. Some even cite mythological references to justify its use," Ruchika Kumar, an administrator at a private detoxification help centre in Delhi, told IANS.
"In many cases, parents fail to spot the erratic behaviour of their ganja-smoking children. Some tell-tale signs are the tendency to stay away from home and excessive partying," said Gupta.
He said a ganja-laced cigarette spews smoke that has a peculiar and pungent smell, very different from a normal tobacco cigarette.
"Parents who know that their ward is a smoker need to react if they notice such pungent smoke around their children's rooms or belongings."
