IT is a booming underground trade that now links the mountains of the Burma-India-China border with high schools in Japan and Thailand. The region's drug law enforcement agents this week decided the scourge of amphetamine and methamphetamine stimulants across the region could no longer be ignored. Fearing the first signs of trafficking syndicates now spanning the region, Japan announced an international co-operation drive to seal the borders of Southeast Asia after a two-day conference in Tokyo. But even as Japan confirmed a funding deal worth US$1.82 million (HK$14 million) the human cost exacted by the trade became alarming clear. In Chiang Rai in northern Thailand, police announced that a single mother was being held after confessing to hiring a hit-man to execute her only son to free him from a life mired in worsening addiction to methamphetamines. In nearby Udon Thani, a father turned his 14-year-old daughter over to police custody after battling in vain for more than a year to free her from a habit she picked up in school. Thai police said they expected Indochina to be the focus of the drive, reflecting Thailand's vast market of an estimated 1.2 million addicts fuelled by factories producing methamphetamine pills hidden in fortified redoubts in the jungles of Laos, Cambodia and Burma. 'Our intelligence suggests many networks that once produced heroin in our neighbouring countries are simply switching trades with the corrupt assistance of police and soldiers on all sides,' a senior Thai agent said. 'Methamphetamines are where the money is now and they are a lot harder to control than heroin.' An estimated 200 million tablets moved into Thailand last year - a trade so vast that dealers have sought new markets ranging across Southeast Asia to southern China and Japan. Tokyo authorities claimed this week they feared an estimated 2.18 million Japanese were now abusing stimulants. Previously injected, smoked or snorted, methamphetamines in pill form have opened a whole new urban market and allowed dealers to target teenagers with candy-shaped tablets. Traditionally abused by truck drivers and labourers working long hours, the stimulants are now popular with young middle-class elites seeking a cheap 'feel good' high without the stigma of needles or glass pipes. Paranoia, depression and sometimes violent nervous breakdowns quickly follow addiction to a drug that now has limited use in modern medicine, doctors warn. Herbert Schaepe, secretary of the United Nations' International Narcotics Control Board in Vienna, said he feared Southeast Asia was cursed by being sandwiched between India and China - the two largest producers of the ephedra shrub, the source of ephedrine - a key ingredient of the amphetamine family. He said both India and China enforced strict official controls on all production of ephedrine but the burgeoning private sectors of both countries could be responsible for 'leakage'. 'There is obviously a growing problem out there and it could be difficult to control. It has to remembered that there is still a legitimate medical use for ephedrine.'