Why Depression Makes It Harder To Quit Smoking

raquel arocena torres/Moment/Getty Images

As anyone who has battled with it could tell you, depression is never a particularly fun thing to deal with, but a new study that's just been published this week by the journal Addiction is making big waves for its revelation about a way that depression impacts sufferers' health. Apparently, according to a team of researchers from Yale School Of Medicine, the Cancer Council of Australia and Melbourne's Centre for Epidemiology and Biostatistics, suffering from depression makes people more likely to try to quit smoking, but it also means they're less likely to be successful at it.

So what does this mean? Are depressives less realistic about their abilities, more prone to temptation, or just far more vulnerable to the pull of nicotine? The answer's not so simple. It actually fits into a bigger picture (and bigger questions) about depression, its relationship to addiction, and its many diverse effects on the brain and the body. Depression may make quitting smoking harder, but the reasons why are more complex than just "depression sucks and makes things terrible." (Although that is definitely part of it.) So what's really going on here?

Let's examine what the science says about the weird marriage between depression and tobacco addiction and where it fits in the pantheon of neurological difficulties caused by depression.

Why Quitting Smoking Is Harder For Depressives

In the new study, a team of scientists brought together 6811 smokers across Canada, Australia, the US and the UK. They were looking for something specific: did depression make people more likely to want to quit smoking, and did it have any effect on whether they were actually able to successfully quit?

The researchers tracked their thousands of subjects through their different quit attempts, and found something tricky: depression, it seems, helps motivate people to try to quit smoking, but it also makes it more likely that the attempt will fail and they'll be back on the cigarettes within a month of quitting. And, sadly, the scientists also looked at gender breakdown, and found that this tendency to relapse seems to actually be stronger in depressive women. So depressives are caught in a nasty cycle: they try to quit more often than non-depressed folks, but also fail more often.

There's a very strong link between depression and substance abuse of many kinds, from alcohol to cigarettes to heroin. In the United Kingdom, for instance, smokers are twice as likely to have depression than non-smokers. This may just be an understandable predilection to self-medicate, but there are other possible explanations, too. The Neuroscience Department at the Mount Sinai School Of Medicine, for instance, is working on understanding why addiction and depression seem to coexist so often. They point out that "it is striking that the brain regions implicated prominently in depression are the same as those implicated in addiction. This is not surprising, since key features of both conditions involve abnormalities in the same behavioral domains (e.g., reward, pleasure, motivation, neurovegetative functions)." Basically, a depressive brain looks very similar to an addictive brain, and that may mean they share some key vulnerabilities.

But it's not just neurological; the inability to successfully quit might be genetic, too. New science is revealing that genetic predisposition left over from Neanderthal ancestors may make certain people more vulnerable to depression and specific addictions. That study, just published in Science, looked at the genetics of 28,000 US citizens, and found that possessing specific Neanderthal genes seems to seriously raise your likelihood of both depression and tobacco addiction.

Worryingly, the relationship goes further: studies have also demonstrated that cigarette smoking might make depression symptoms worse, as well as vice versa. So depressive people with tobacco addictions are caught in a strange knot that it's tricky for us to untangle. In any case, it looks like the depressive brain puts up a lot of road blocks when it comes to quitting smoking. And, unfortunately, that's just one of a host of habits that depression seems to hinder in our lives.

This Is Just One Of The Things Depression Makes Difficult

Depression doesn't just mean that you're lumping about, feeling sorry for yourself; it's a serious neurological condition with far-reaching consequences. And not being able to quit smoking with ease is just one of 'em.

Depression interferes with a lot of neurological functioning, from the extremely basic to the highly complex, with knock-on effects for the body and behavior in general. Reading complex literature can be extremely hard for people with depression, as it requires what's called "effortful" mental processes rather than "automatic" ones. This is because of what depression does to concentration levels, which can be summed up as "causing havoc." Reading comprehension, focus, the ability to tune out distractions and fully absorb new information are all derailed by depression; so with depression, War & Peace suddenly turns from a piece of great literature into a confusing morass of Russian names.

It also causes memory dysfunction. Partially that's because of concentration problems — you can't remember stuff properly if you weren't paying full attention to begin with — but studies have also shown that depressive people may have problems with what's called the "search and retrieval processes," in which you rummage around in your memory and bring out what you were searching for. The information you're trying to absorb may not land in your brain to begin with, and if it does, you may have trouble getting it out.

And then there's the more basic stuff, like motor skills. Depressives occasionally do poorly on tests of their coordination and ability to control their hand movements minutely; it doesn't seem to be widespread, but it's definitely a possibility. The real bits that seem to suffer are the psychomotor skills, which involve coordination between the brain and the relevant parts of the body, like writing or catching balls.

So What Does This All Mean?

The overall message to get from this isn't that depression is hopeless and makes sufferers into doddering lunatics. It's that depression is real and not just "in your mind," and that difficulty quitting an addictive substance while suffering from it isn't reflective of a lack of willpower or some kind of personal weakness. It reflects the neurological reality of certain vulnerabilities in your brain, and we're still trying to understand exactly how and why they work.

But, on the bright side, quitting smoking may do you more good than just removing tobacco-related health risks; a 2014 study in the British Medical Journal found that symptoms of depression, anxiety and stress seriously dropped after people quit smoking. The researchers actually found that quitting smoking was as effective as being on antidepressants. Something to put in your pipe and smoke (or not).

Images: raquel arocena torres/Moment/Getty Images, Giphy