Happiness and Other Diseases

& this one in CHEMTECH January 1997

I was reading recently about work that drew a link between clinical depression with infection with a particular virus, and it set me thinking. If it turns out there are such things as mood-altering viruses, the implications are astonishing. Psychiatry and psychology would be revolutionised. It could herald the end of the world as we know it, or at least affect the result of the next election.

My first question on reading the piece was: "What’s in it for the bug?" What evolutionary advantage does the virus gain by making its victim miserable? Is it particularly fond of alcohol, or nicotine, or chocolate? More probably, acute depression could lower the body’s immune response, making the virus’s life easier. Do immuno-suppressed people get depressed more easily than the rest of the population? I suspect that they do. Of course the symptom could merely be an unfortunate side-effect of the infection, conferring no benefit to the pathogen.

Does the virus tend to spread more in winter, like influenza, offering an alternative explanation for S.A.D? Depression is more prevalent in some countries than in others. Does this imply that some populations have a natural resistance to the disease?

Whatever, imagine what a biological warfare establishment could do with such a beastie. Virulent infectious or contagious strains could be released into enemy nations, to sweep through the populace, damaging economic output and reducing the will to fight. In response, security forces would have to mount a special look-out at the airports for sad people trying to enter the country. On the other hand the bugs could be targeted at political leaders - watch out for those hand-shakes at summit meetings.

If the depression is only a side-effect, if perhaps the brain’s reaction to certain antigens involves the production of a depressant, or if the virus just happens to excrete a psycho-active chemical, then many other possibilities arise. Could other moods be influenced by infections? Violent anger, perhaps. Are the world’s trouble spots plagued by endemic psychoviruses? All sorts of obsessive or deviant behaviours could be candidates.

Obviously if there are such infectious diseases about we would need to find treatments for them. But interesting public health questions then come to mind. Should we consider attempting to eradicate these viruses, by compulsory medication? There would certainly be pressure to stamp out what society sees as "bad" moods. A Brave New World wouldn’t seem too far off if we were all forced into being nice and happy for the public good.

There could even be infections with positive side-effects, such as increased self-confidence or euphoria. . You can imagine people deliberately contracting such "diseases", associating with known "victims". Perhaps that’s why highly self-assured types tend to attract hordes of admirers. Capsules containing the bugs would be sold illicitly at street corners or pushed in pubs. Maybe national mood-swings could simply be the results of competing epidemics of "positive" and "negative" psychoviruses.

If a "happiness bug" doesn’t exist, could we engineer one? Governments could release it just before general elections. Maybe they’ve been doing it for years. That could explain how they keep on getting back in. OK, that sounds like paranoia, but who’s to say that paranoia’s not caused by yet another pathogen?