Smoking and Depression: What Is the Link?

Depression ranks among the most common disorders anywhere, and also one of the least understood. A person dealing with it may feel discouraged, sad, hopeless, drained of motivation, or simply uninterested in daily life (Anxiety and Depression Association of America, 2014). Plenty of people carry it without ever naming it. Lately, research has drawn a connection between smoking and this condition.

Ask the average smoker why they light up and you'll hear a familiar set of answers: to take the edge off stress, to feel calmer when things get heavy, maybe to keep weight in check. This despite smoking being one of the top causes of early death. Certain studies suggest that people with depression account for a large share of those who smoke.

The picture isn't that clean, though. Before deciding that smoking causes depression, or that depression pushes people toward cigarettes, there are other variables worth sitting with. Not everyone who is depressed reaches for a cigarette, and not everyone who smokes to unwind is depressed. Smoking might simply be one coping strategy among many, one that happens to be cheap, legal, and within arm's reach.

The Brain and Depression

When neurotransmitters fail to carry a message from one neuron to the next, the brain either misses that message or receives it late. A quick clarification: a neuron is a nerve cell, and a neurotransmitter is a brain chemical that ferries signals between neurons. Several of these chemicals shape how we behave, touching mood, anger, fear, and memory, among other things. A handful of them keep coming up in discussions of depression.

Acetylcholine supports memory and plays a role in learning and recall; depressed people tend to have less of it. Serotonin manages sleep, appetite, and mood, and it dampens pain; again, lower in depression. Dopamine drives motivation and movement, and it too runs low. GABA, which quiets and relaxes the nervous system, follows the same pattern.

When these chemicals drop too far, the fallout can include psychosis, hallucinations, suicidal thinking, and, no surprise, depression. Low serotonin alone can leave a person swinging between moods or losing their appetite. (Harvard Health has more on how neurotransmitters feed into depression, at www.health.harvard.edu.)

The brain is a formidable organ, and any harm to it ripples out into behavior, thought, and emotion. Faced with a chemical imbalance, the brain goes looking for a fix. It doesn't always pick a good one. Some people land on cigarettes as a way to shift their chemistry for a little while; others reach for something that actually helps, like exercise. Which does your brain reach for?

Research

Studies have found that a lot of people smoke specifically to make themselves "feel better" by nudging their brain chemistry. Part of the difference comes down to self-efficacy, meaning how well someone can regulate their own inner states. People high in it manage those states from within. People lower in it tend to lean on outside factors to steer how they feel.

In her published work, Self-Efficacy: A Mediator of Smoking Behavior and Depression among College Students, Susan Mae reports that smokers with low self-efficacy are more prone to depression and more inclined to use smoking as a way to cope (Mae, 2014).

Depression Is Not Unique to Smokers

By some accounts, the soundest way to deal with depression is medication paired with behavioral guidance from a licensed professional, and many clinicians work with clients who have fallen into unhealthy coping habits to blunt their symptoms. Still, there's a large group of people living with depression who take no medication and get through their days without trouble. Others turn to faith, to writing, to exercise, finding their footing without the unhealthy routes. That belongs in the conversation too.

How do you cope with depression?

Heather Browning, MBA, BA Psychology

Mae, Susan. (2014). Self-Efficacy: A Mediator of Smoking Behavior and Depression among College Students. Pediatric Nursing. 12, 40(1).