So now we know what has long been suspected: Philippine President Rodrigo Duterte has a history of drug dependence greater than that of most of the 6,000 or so murdered during his anti-drug campaign.

Duterte has admitted past regular use (and over-use) of Fentanyl, the most powerful of all the opioids known. It is far more powerful than morphine – not to mention of opium itself. It usually only officially administered under strict control from those suffering the most serious pain from cancer or chronic diseases. Whilst doing the job of pain relief, it also is known to affect the brain in such a way as to alter normal behavior and judgment These latter are clearly evident in Duterte’s erratic lifestyle, many outbursts and some of his decision-making – not least his sudden abandonment of his nation’s victory over China at the Court of Arbitration on its rights in the West Philippine sea.

The line between legal and illegal drugs is a fine one, often defined simply as access to a doctor prepared to sign a prescription. Necessarily this forces other would-be users to buy street products whose strength may be uncertain and which may be mixed with other drugs such as cocaine and heroin.

Duterte now claims to have kicked the Fentanyl habit but that simply leaves the question of what alternative opioids he may now be using on a regular basis. Nothing in his behaviour has suggested a return to a more normal lifestyle and to the kind of considered judgements and dignified conduct expected of a president. His latest boasting of personally killing unconvicted crime suspects in cold blood suggests he neither knows nor cares about the law.

Dependence on any powerful opioids for pain control is bound to affect judgment. Someone not allowed to drive a car – a normality required of those dependent on such drugs – has no business being the activist president of a nation of 100 million people.

The president’s past and possible continuing dependence would appear far more serious than that of perhaps thousands of occasional and regular, but not addicted, users of the methamphetamine shabu, the most common street drug in the Philippines. Taken on occasion for recreational use, for example at parties, its risk is, unless adulterated, is slight compared with strong opioids, whether legally prescribed or not.

Statistics from the United States show that in 2014, there were 18,000 deaths from opioids compared with 10,000 from heroin and 5,000 from cocaine. The total deaths from all prescription drugs was 25,000, far in excess of those from illegal ones.

Relatively few in the Philippines, compared to the US, have access to opioid prescription drugs. But the illegal ones they buy are mostly of relatively less dangerous methamphetamines. The Philippines is by no means unique in having a large population of at least occasional users of these. Thailand has long had similar issues – and a “drug war” on the part of then Prime Minister Thaksin Shinawatra that took 2,800 lives in three months. An investigation later determined that half of those murdered by police had nothing to do with drugs. They stemmed from police settling scores with enemies or mistakes or other issues. That ought to sound familiar at Malacanang Palace.

After the failure of Thaksin’s campaign of killings of supposed drug dealers, Thailand has now admitted that social rather than criminal measures are the way to approach the problem. Malaysia, Hong Kong and Japan are other places where reactional use of illegal drugs is common but deaths relatively few.

So far there seems no limit to the self-humiliation the Philippine people are undergoing as they continue to support Duterte despite his glorification on illegal killings and his near treasonable surrender to China over its sea and island rights. But eventually it is hoped that there will be an end. And a nation will find itself covered with shame.