Previous research had suggested that because house cats are the primary hosts of the parasite Toxoplasma gondii—and that parasite has, in turn, been linked with several neurological, mood, and psychiatric disorders—living with a cat would increase the risk of developing the latter. Solmi’s large study suggests that isn’t the case. (Pregnant women, though, still shouldn’t handle dirty kitty litter, where T. Gondii often lurks, because of the risk of toxoplasmosis.)

Indeed, it’s been boom times for non-associations. Last month, a study in the British Medical Journal found that having a high body mass index (BMI) measure in pregnancy does not necessarily lead to having obese children. And the National Academies of Sciences, Engineering, and Medicine released a report concluding that marijuana does not cause lung cancer.

An earlier Italian study (ahem) clears eating pasta of any link to obesity. UCSF researcher Shalini Dixit and colleagues found that drinking coffee doesn’t lead to an irregular heartbeat. Another study found that letting an infant cry herself to sleep isn’t going to cause harm. (It did not address whether the parents themselves will descend into a deep chasm of irredeemable guilt.) And finally, a decade-long study of nearly 720,000 UK women concluded that happiness does “not appear to have any direct effect on mortality.”

So what about cigarette smoking? “Smoking has been found to harm nearly every bodily organ and organ system in the body and diminishes a person’s overall health.” For God’s sake, quit.

This essay appears in today’s edition of the Fortune Brainstorm Health Daily. Get it delivered straight to your inbox.