What happens when you start smoking early in your life?

Do you smoke? When did you start smoking? What do you feel when you smoke? Are you a regular smoker or just a social smoker? These are some questions that have often been addressed in research studies. Today, I will share with you an interesting smoking-related question that has not been investigated much. More precisely, to my knowledge, this is the only study so far, that took into account this issue that has been discussed below. 

Smoking and health

It is well documented and generally known that smoking can cause physical illnesses such as lung cancer and heart diseases. However, there is less public awareness about the adverse effects of smoking on mental health. 

Previous research has shown that as compared to never-smokers or quitters, those who are currently smoking are more likely to experience symptoms of depression and anxiety disorders. Longitudinal research has demonstrated that those who start smoking develop a mental illness subsequently, even if they are healthy at the time of starting smoking. However, there is uncertainty about the underlying causal factors of this association of smoking and mental illness. 

The study

This research has investigated the hypothesis that age at smoking initiation will be a crucial factor in developing depression and anxiety disorder later in life. Those who start smoking at a younger age will experience depression/ anxiety symptoms sooner in life, as compared to those who start smoking later in life. In other words, it will take less time for early-onset smokers to experience the symptoms of depression or anxiety as compared to late-onset smokers.

The rationale behind this hypothesis was some findings from animal research. Rats were exposed to nicotine at a younger age and it was observed that they showed low motor activity and less interest in reward (food), some characteristics of depression in animals.

For this study, 1055 smokers were selected from an ongoing longitudinal study called NESDA. These were the people who had developed a mental illness after they started smoking. Smoking behavior was assessed by a questionnaire that included questions related to past and current smoking behavior of the participants. Age at smoking initiation was defined as the age at which the participants started smoking regularly. Social smokers were excluded from the study. 

Two groups of smokers in this study were: 

(i) Early-onset smokers, those who started smoking between the age of 10 to 15 years; 

(ii) Late-onset smokers, those who started smoking after the age of 15. 

The presence of depression and anxiety was assessed by a validated clinical interview with tested reliability. In this study, the effects of gender, education and childhood were controlled because it has been reported that trauma in childhood, whether physical or mental, low education and being female are associated with adverse mental health later in life. Therefore, any relation between smoking and mental illness will be because of smoking and not because of these factors.

Age at which smoking is initiated is crucial

It was found that individuals who started smoking after the age of 15 years took longer to experience adverse mental health and symptoms of depression and anxiety disorders as compared to those who started smoking before the age of 15 years. In other words, those who started smoking between the age of 10 to 15 years developed depression and anxiety disorder sooner as compared to those who started smoking after 15 years of age. The study reported that there was almost 5 years difference between the two groups of smokers, mentioned above, to develop depression or anxiety disorder or both.

Though, the mechanisms that underlie the association of smoking at an early age and mental illness are unclear, but it can be speculated that at the younger age, the brain is still developing and therefore, is more sensitive to the detrimental effects of nicotine. 

This study provides a reason for the smoking prevention programs to focus on children and adolescents. Parents and teachers should also be well educated about the adverse effects of smoking on mental health. Awareness programs should be regularly organized in schools and community centers.

More details about the study, the participants, and the data collection tools can be found in Nicotine and tobacco research