Statistical data demonstrate a concurrent rise in smoking prevalence and mental disorders, such as depression and anxiety, which may be attributed to contemporary lifestyle factors, including social media and recent global events. This indicates a potential correlation between these trends, as individuals with mental disorders may engage in smoking as a form of self-medication to alleviate anxiety. However, smoking is harmful and increases the risk of many diseases. Therefore, smoking cessation strategies are increasingly being considered. Nicotine is a naturally produced alkaloid in plants that makes smoking so addictive. Unfortunately, the public’s lack of understanding of the effects of nicotine leads to misleading claims in the public and media about its biological effects. Thus, current narrative literature review is focused on the examination of the biological effects of organic nicotine from various angles, considering the psychological aspects of addiction and the immune system. Analysis of recent data showed that nicotine not only causes addiction but also has therapeutic benefits in certain diseases (depression, anxiety, schizophrenia) and has anti-inflammatory properties (autoimmunity, neurodegenerative diseases), and a deeper understanding and a broader approach to its effects is needed.

Background and Objectives: One of the strongest early factors influencing later psychoactive substance use is adverse childhood experiences (ACEs). Studies investigate a variety of adverse experiences in relation to substance use, yet not all adverse childhood experiences are equal in intensity and harm. Our study aimed to address this gap by examining in detail the associations between individual ACEs, broader ACE categories, and different forms of psychoactive substance use. Materials and Methods: The study included 709 participants who completed self-report questionnaires. ACEs were measured using the MACE questionnaire. Marijuana use was measured using the CUDIT-R, alcohol use using the AUDIT, and heavy psychoactive substance use using the ASSIST. Linear regression analyses were used to predict associations. As expected, only a small part of the sample reported hard drug use; some analyses are limited to substantially fewer observations. Results: All regression models were statistically significant and predicted all three categories of psychoactive substances, but if we count the individual adverse experiences, the results become different. Although the results showed that ACE is a significant predictor of hard drug use and explains 25% of the variance, it is separately only emotional neglect that is associated with hard drug use. The regression analysis also explains 14% of the variance in marijuana use, but when considered separately, we found associations only with emotional neglect. The severity of alcohol use explains 13% of the variance, but only a few ACEs reach statistical significance: peer physical bullying, physical violence, and sexual abuse. Conclusions: The findings of our study suggest that adverse childhood experiences may not be qualitatively equivalent and therefore may not be evaluated only as a cumulative risk score. Separate ACE evaluations, instead of aggregate calculation of ACEs, may be useful to understand better which specific negative experiences have the greatest impact on subsequent use of psychoactive substances. The regression models explain only a small portion of the variance, which suggests that other factors may contribute to a larger share.

Background and Objectives: Tobacco smoking is associated with an increased risk of depression and anxiety symptoms, but it remains unclear whether this relationship differs according to the type of nicotine product used. The increasing popularity of heated tobacco products has created a need to better understand their association with mental health, particularly in comparison with combustible cigarettes. Therefore, this study aimed to compare the prevalence of depression and anxiety symptoms among combustible cigarette (CC) users, heated tobacco product (HTP) users, and non-smokers. Materials and Methods: A cross-sectional study was conducted among 497 adults. Participants were classified into three groups according to their tobacco-use status: combustible cigarette smokers, heated tobacco users, and non-smokers. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and anxiety symptoms were assessed using the Generalized Anxiety Disorder-7 (GAD-7). Group differences were evaluated using hierarchical linear regression analyses adjusted for sociodemographic, health, and lifestyle factors. Results: Tobacco-use group significantly improved the model fit for PHQ-9 (ΔR² = 0.0575, p < 0.001) and GAD-7 (ΔR² = 0.0764, p < 0.001). In non-smokers, scores of depression were 3.48 lower than in CC users and 1.42 lower than in the HTP users’ group. In HTP users, these scores were 2.06 lower than in the CC users’ group. Anxiety scores were 3.71 lower in non-smokers than in CC users, and 1.29 lower than in the HTP users’ group. In the HTP users’ group, this score was 2.42 lower than in the CC users’ group. HC3 robust standard errors with 5000-sample BCa bootstrap confidence intervals and reduced-adjustment sensitivity analyses confirmed the primary pattern. Conclusions: Our study results showed that combustible cigarette users had the highest adjusted depression and anxiety scores, HTP users had intermediate scores, and non-smokers had the lowest. In both tobacco-using groups, greater product-specific nicotine dependence was associated with higher PHQ-9 and GAD-7 scores. Further interdisciplinary studies incorporating biomarkers of nicotine exposure, HPA axis function, inflammation, and oxidative stress are needed to clarify whether the observed differences reflect the characteristics of individuals who choose specific tobacco products or are partly attributable to product-specific effects.

Adverse childhood experiences (ACEs) are recognized risk factors for later substance use. Yet, data remain scarce—particularly regarding the differentiated effects of specific types of ACEs and their distinct associations with various psychoactive substances. The current study is one of the first in Lithuania to explore the associations between specific ACEs and psychoactive substance use in young adulthood (ages 18–29). This cross-sectional study included a total of 709 participants who completed an online survey. ACEs were measured using a combination of adapted ACEs items and the MACE questionnaire. Substance use was assessed using self-reported instruments: CUDIT-R (cannabis), AUDIT (alcohol), ASSIST (heavy psychoactive substances), and nicotine use. Structural equation modeling (SEM) was chosen to examine predictive relationships. Results revealed that experiences of sexual abuse and physical maltreatment in childhood predicted higher levels of alcohol use in young adulthood. Sexual abuse was positively associated with nicotine, cannabis, and heavy psychoactive substance use, while witnessing interpersonal violence was only associated with higher nicotine use. However, verbal abuse showed significant negative associations across several substance categories. No significant associations were found between family addiction history and substance use. The absence of an important relationship between family history of addiction and substance use indicates that genetic factors may be less decisive than environmental or psychosocial conditions. The main findings of this study are that ACEs are not qualitatively equivalent to one another, so it is worth examining them separately, rather than summing them. Furthermore, based on the negative associations with verbal abuse and the generally statistically negative associations, we can assume that ACEs may not be the most important factors increasing substance use. Further studies should look for other factors that influence substance use.