Cigarette smoking and mental health problems often go hand-in-hand.
But which one typically comes first? And how much does our genetic makeup contribute to this risky combo?
New research examined these questions by analyzing long-term health data on over 300,000 people in the UK.
Key Facts:
- Smoking initiation typically happened in adolescence, before the first signs of mental illness. This suggests smoking may contribute to developing disorders like depression later on.
- Genetic factors increased people’s chances of taking up smoking and of being hospitalized for mental health issues. But behavioral factors (being a smoker) had just as big an impact.
- Previous smokers had a 50% higher risk of mental health hospitalization compared to people who never smoked. For current smokers, the risk was more than doubled.
- Preventing smoking in youth could potentially stop mental illnesses from developing later in life. People who manage to quit smoking before middle age also see benefits.
Source: Acta Psychiatrica Scandinavica (2023 Aug 21;e13601.)
The Early Origins of Smoking
The researchers utilized data from a large long-term health study in the UK called the UK Biobank.
Over 500,000 British adults age 37-73 participated starting back in 2006.
Participants completed health questionnaires, physical measurements, and donated blood samples for genetics analysis. The study tracked their health outcomes over time.
The research team focused on hospitalization records for mental illnesses – including depression, bipolar disorder, and schizophrenia.
They also looked at participants’ self-reported smoking behavior.
Most smokers started lighting up during adolescence, the analysis found.
For the vast majority who took up the habit, initiation happened between ages 15-19.
In contrast, first hospitalizations for mental health conditions tended to happen much later in life.
On average, people were hospitalized in their 60s for mood disorders like depression.
For schizophrenia, the average age was even higher.
This clear separation in time suggests smoking often precedes mental illness.
The brain changes that lead to disorders like depression may unfold slowly over many years after starting to smoke.
The Influence of Genetics
Of course, mental illness doesn’t have any single cause.
Genetics play a major role in a person’s vulnerability.
The research team wanted to analyze how genetic factors intersect with smoking behavior.
They calculated a “polygenic risk score” for each person.
This measures genetic variants linked to higher chances of smoking and mental illness.
Having a high genetic risk score increased a person’s likelihood of taking up smoking as a teen.
It also meant higher odds of hospitalization for mental disorders later on – regardless of whether they smoked.
But when the team looked at all factors together, genes weren’t necessarily destiny.
Being a current or former smoker carried just as high a risk for mental hospitalization as having an elevated genetic score.
This means behavior and environment are just as pivotal as genetic makeup when it comes to poor mental health.
The High Cost of Smoking
Comparing smoking habits revealed that current smokers fared far worse in terms of mental health.
Their risk of hospitalization was more than double that of people who had never smoked.
Former smokers fell somewhere in the middle.
On one hand, this gap may reflect changes in brain structure and function caused by smoking.
Chemicals in cigarettes potentially set off inflammation and alter important signaling in the brain over time.
But smoking could also take a psychological toll that amplifies the risk of mood disorders.
For instance, becoming dependent on cigarettes despite negative consequences can negatively impact self-esteem.
Smoking-related stigma or discrimination may also contribute to social isolation and poor mental health.
More research is needed to clarify the mechanisms involved.
But regardless of the “how”, the takeaway is clear: smoking comes at a high cost for long-term mental health.
Prevention Opportunities
Given that smoking often starts in the teen years, preventing initiation early on is key.
Educating adolescents about smoking’s risks could steer them away from a habit that can have cascading effects on mental health later.
For those who do end up smoking, quitting before middle age seems to provide some protection.
In the study, people who quit earlier had lower subsequent rates of hospitalization compared to those who continued smoking.
But it’s never too late to quit. Prior research shows that kicking the habit at any age brings both physical and mental health benefits.
Counseling and smoking cessation aids can help people successfully quit.
Doctors and mental health professionals also need to discuss smoking risks with patients displaying early signs of disorders like depression.
They can connect those patients with support to quit smoking while also pursuing other treatments.
This dual approach gives patients the best chance at recovery.
Overcoming Hurdles
Yet there are hurdles in addressing smoking among mental health patients.
Many view smoking as a convenient coping strategy for anxieties or boring moments.
Doctors themselves often feel ill-equipped to provide smoking cessation counseling.
To reduce smoking-related harm, care teams will need better training for having these difficult conversations.
Mental healthcare should also incorporate quitting strategies that address cravings and substitute healthier coping habits.
Peer support groups may help patients feel less alone on their journey to quitting.
The research underscores that smoking and poor mental health go hand in hand.
While genetics load the gun, behavior pulls the trigger when it comes to long-term health risks.
Supporting healthy choices – especially early in life – can help people avoid years of suffering down the road.
With greater awareness and the right tools, people and healthcare providers together can break the smoking and mental illness cycle.
References
- Study: Using polygenic risk scores to investigate the evolution of smoking and mental health outcomes in UK biobank participants
- Authors: Lloyd Balbuena et al. (2023)
