An Exchange on Correlation and the Possible Dangers of Some Drugs,Legal and Illegal

What follows is a posting from 'Theo', a  reader of my Sunday column, and my responses interleaved and marked ***.

I felt it deserved a posting of its own. 'Theo' is of course welcome to reply at length. 

 

Theo: The use of Anti depressants by one of the columbine shooters? CORRELATION IS NOT CAUSATION... a psychologically disturbed individual with suicidal and homicidal thoughts was taking anti depressants, wow, what a revelation!

***PH writes: Indeed, correlation is not causation. But it is also the case that correlation is not necessarily *not* causation. On the contrary, it is the foundation of epidemiology. This is why I call for an inquiry, to see if the correlation is meaningful (as some are) or meaningless) as some are). I cannot see why any open-minded person could possibly be against such an inquiry.

Theo: As for 'a psychologically disturbed individual with suicidal and homicidal thoughts was taking anti depressants, wow, what a revelation!', this remark is neither as clever nor as conclusive as he seems to think. Unhappy people, of whom there are many, often have nothing physically or measurably wrong with them and are not objectively distinguishable from happy people, by any scientific test (with the possible exception of an absence of physical exercise from their lives, see below) .

PH: It is possible - and despite being jeered at for saying this when I first did so I now find considerable research support for the suggestion ( eg http://bit.ly/1P7Vt4n )- that the widespread absence of serious physical exercise common in advanced western societies may explain a great deal of the otherwise inexplicable unhappiness known as ' clinical depression'. There may be other explanations. I do not know.

But as soon as a person begins taking the chemicals known as 'antidepressants' he or she alters his or her brain and body , quite possibly irreversibly.

While crowd madness is frighteningly common, severe irrationality (especially associated with violence or suicide) is actually quite rare in individuals and is often associated with some sort of external trauma, whether induced by violence or drugs. Until quite recently, most suicides were readily explicable by the inescapable desperation of the suicide's position, and, in a horrible way, rational. Now, it is often the case that devastated relatives tell coroners (I read a lot of these cases in local newspaper reports) that they had no idea the suicide was so unhappy, and cannot explain the action. Almost invariably, I find that the subjects of these puzzling cases are said (often in passing with no further interest shown by the coroner) to have been 'depressed' or 'undergoing treatment for depression', which I would judge usually means that they were taking some sort of 'antidepressant' medication. I was almost absolutely sure when I heard of the Lubitz case that it would emerge that he had been taking such pills, or possibly was a cannabis user. As I always do, I held my tongue while I waited for the details. There would just have been a lot of ignorant howling if I had speculated without data, and the lack of information would have made it impossible to resolve it at the time. Being proved right later wouldn't have made up for this.

As I almost always find, my speculation was eventually found to be correct. As I almost always find, nobody drew any conclusions from this.

It is also the case that quite a lot of such chemically-associated suicides are no longer recorded as such, and are registered under such vague categorisations as 'narrative verdicts', thus making the statistics unreliable.

It is also now pretty much accepted ( see Nordic Cochrane Centre reports January 2016) that 'antidepressants' make suicide more likely among the young. I have never seen any good reason for supposing that this might not apply to those who are not young, and the research which established this link did not in fact rule out the possibility that it might apply to others as well.***

Theo: It's very similar to you always pointing out how a lot of terrorists and killers happen to have smoked lots of marijuana, well yeah lots of disturbed people happen to fall in to substance abuse and consume drugs and alcohol.

****PH writes: Yes, it is similar, and essentially the same point. And the same argument applies. People who take serious mind-altering chemicals whether on prescription or illegally via criminal dealers are exposing their physical brains to possible physical and chemical alterations and effects ( quite possibly permanent effects) which go way beyond the effects of personal distress or unhappiness, and might well, as a result, undertake behaviours well outside the normal range of human actions. ***

How easy do you think it would be to find dozens of pacifist philanthropists and heroes who smoke lots of cannabis? I'm guessing pretty easy, one could easily identify such people and say, 'look they're smoking lots of cannabis and doing all these good things, so cannabis must make you do good things. The pilot who crashed the plane most likely did so because he was suffering from severe depression and psychological issues, hence why he was taking the anti depressants. Psychologically disturbed and sick people often take drugs, either through prescription or by self medication, or both.

***I find this argument evasive and also designed to avoid further investigation. My position is that there is a matter here that plainly needs to be investigated properly. Once again, I have not suggested that *every* person who takes such drugs becomes a violent killer or kills himself. Not every cancer sufferer dies. But if in some extreme cases there is a link between such drugs and such actions, it would tend to suggest that the drugs themselves might not be as 'soft' or 'safe' as their promoters and defenders suggest. We should therefore, at a minimum, be more careful about allowing people to use them than we are****