What The Internet Thinks About Antidepressants

Toronto team Rizo et al offer a novel approach to psychopharmacology: trawling the internet for people's opinions. It's a rapid, web-based method for obtaining patient views on effects and side-effects of antidepressants.

They designed a script to Google the names of several antidepressants in the context of someone who's taking them, and checks to see if they describe any side-effects.

A large number of URLs were rapidly screened through Google Search™, using one server situated in Ohio, USA. The search strategy used language strings to denote active antidepressant drug usage, such as “I'm on [name of antidepressant]…” or “I
have been on [antidepressant] for ….”, or “I've started [antidepressant]…”, or “the [antidepressant] is giving me or causing me…”

They then used a thing called OpenCalais™ to read the search hits and decide whether they were mentioning particular diseases or symptoms. OpenCalais is a natural language processor which is meant to be able to automatically extract the meaning from text. However, to make sure it wasn't doing anything silly (natural language processing is quite tricky), they manually checked the results.

What happened? They found about 5,000 hits in total from people taking antidepressants, ranging from 210 for mirtazapine (Remeron) up to 835 for duloxetine (Cymbalta). That doesn't seem like all that many considering they searched on the entire internet, although they only searched English language websites.

Anyway, drowsiness, sleepiness or tiredness was mentioned in from 6.4% (duloxetine) down to 2.9% (fluoxetine) of the hits. Insomnia was noted in 4% (desvenlafaxine) down to 2.2% fluoxetine. And so on.

These results are a lot lower than anything previously reported from clinical trials, where the prevalence of drowsiness, for example, is often around 25% (vs. 10% on placebo); with some drugs, it's higher. So there's a big discrepancy, and it's hard to interpret these results. Maybe lots of people are having side effects and just not bothering to write about them. Or they're too embarrassed. Etc.

Still, it's a very clever idea it would probably be better used trying to discover which drugs work best. Neuroskeptic readers will know that clinical trials of antidepressants are flawed in several ways. I'd say they're actually better at telling us about side effects (which are probably roughly the same in clinical trials and in real life) than they are at telling us about efficacy (where this assumption doesn't hold)...

Links: There are many websites where people describe their experiences of medical treatments ranging from the fancy to the crude (but much more informative)...

Rizo C, Deshpande A, Ing A, & Seeman N (2010). A rapid, Web-based method for obtaining patient views on effects and side-effects of antidepressants. Journal of affective disorders PMID: 20705344