Coffee and energy drinks have different links to suicidality: what a meta-analysis has found

The first systematic review with meta-analysis on how coffee and energy drinks relate to the risk of suicidal thoughts and attempts was published in Nutrients. The result is contrasting: regular coffee consumption is associated with a reduced risk of suicide attempts (protection is noticeable only at high doses of ≈2-4 cups per day), while energy drinks are associated with an increased risk of both attempts and suicidal ideation, and the increase appears to be dose-dependent. The authors emphasize: these are observational relationships, causality has not been proven, and the overall confidence in the evidence is low to very low.

Background of the study

Caffeine is the most widely consumed psychoactive stimulant on the planet, with an estimated 80% of the population consuming it daily. Sources vary in their “filling”: coffee (≈95 mg/8 oz), black and green tea (≈47 and 28 mg/8 oz), and energy drinks, which contain not only caffeine (≈80-100 mg/8 oz), but also sugar, taurine, and other components. Widespread availability and aggressive marketing have made these drinks a common part of everyday life, raising questions about their impact on mental health.

Suicidality is a serious public health problem, with hundreds of thousands of completed suicides and many times more episodes of suicidal ideation and deliberate self-harm recorded each year. However, the relationship between caffeine and mental health outcomes has been mixed: some studies have linked energy drinks with a higher risk of suicidal ideation and attempts, others have found protective associations with coffee at moderate to high regular consumption, and still others have found neutral or opposite results. This “superposition” of signals requires systematic verification.

The authors emphasize that there has been no review focused specifically on suicidal outcomes (ideation, attempts, self-harm) across different sources of caffeine. To sort things out, they registered the protocol (PROSPERO) in advance, followed PRISMA, separated coffee from energy drinks, and attempted to account for dose by standardizing consumption in “cups per month” for meta-regression. This design allows not only to bring together disparate results, but also to assess possible dose-dependence of effects.

The practical motivation is simple: if different caffeinated drinks are associated with opposite risks, this has implications for prevention, from dietary advice to youth harm reduction programs. At the same time, the researchers are aware of the limitations of observational data (confounding by gender, stress, concomitant alcohol/tobacco use), so they view the associations they found as guidelines for more rigorous testing and well-thought-out public policies.

What exactly was studied?

The Singapore team registered the protocol with PROSPERO and conducted a PRISMA review, searching PubMed, Embase, Cochrane and PsycINFO. The analysis included 17 studies with a total of 1,574,548 participants; nine studies were on energy drinks, six on coffee and two on ‘pure’ caffeine. They assessed suicide attempts, ideation and self-harm; effects were summed up as OR/RR and tested with meta-regressions.

Key figures (meta-analysis)

• Energy drinks → suicide attempts. Any consumption at least once a month is associated with an increased risk: OR 1.81 (95% CI 1.43-2.29). Dose-dependence: 1-10 cups/month - OR 1.34; 11-20 - OR 1.61; 21-30 - OR 2.88. The more - the higher the risk.
• Energy drinks → suicidal ideation. Any consumption - OR 1.96 (1.33-2.90); subgroups: 1-10/month - OR 1.37; 11-20/month - OR 2.06; 21-30/month - OR 2.78. Also dose-dependent.
• Coffee → suicide attempts. Coffee drinkers had a lower risk overall: RR 0.72 (0.53–0.98). The protective effect was statistically significant at 61–90 cups/month (≈2–3/day; RR 0.51) and 91–120/month (≈3–4/day; RR 0.57); there was no significance at lower volumes.

Important clarifications

The authors discuss the neurobiology of caffeine (adenosine receptor antagonism, dopamine and glutamate modulation) and behavioral factors. According to their data, men tend to consume more caffeinated products, and alcohol/tobacco/other substance use is associated with high caffeine consumption - these are potential confounding factors. In addition, energy drinks often contain sugar and additional stimulants, which may increase anxiety and emotional instability.

How to read this without sensationalism

These are associations, not proven causation. The body of work includes many observational designs and considerable heterogeneity; doses were often reported as “cups per month,” without precise standardization to milligrams of caffeine. According to GRADE, the certainty of the evidence is rated as low (coffee/energy drinks ↔ attempts) and very low (energy drinks ↔ ideation). Nevertheless, the picture is consistent: coffee (at a level of ≥≈2-3 cups per day) tends to be “protective,” energy drinks to be “risky,” with a dose gradient.

What does this mean in practice (cautious conclusions)

• Energy drinks. It is worth paying more attention to their consumption by teenagers and young adults, especially in cases of stress, anxiety and concomitant substance use. Risk signals increase even with small quantities (1-10 servings per month).
• Coffee. For coffee drinkers, moderate-to-high regular consumption correlates with a lower risk of trying, but this is not a recommendation to deliberately increase doses for the sake of "prevention." Individual tolerance, sleep, anxiety, gastrointestinal tract - all these are important.
• Prevention in general. When working with at-risk groups, anxiety/depression screening, energy drink restriction, healthy sleep and exercise routines are all helpful - all of which are probably more important than any one cup.

Viewing Limitations (Why Caution Is Appropriate)

• Lack of research on self-harm and other sources of caffeine (tea, tablets).
• Large variability in dose accounting (by “cups”, without standardization by mg of caffeine) and in outcome scales.
• Heterogeneity between studies and risk of residual confounding (gender, socioeconomics, co-occurring habits).

Conclusion

The overall picture is simple: coffee is a possible “protective marker,” but only at the level of regular and fairly intensive consumption; energy drinks are a stable “risk marker,” and the more you consume, the more alarming the signal. To turn these observations into practical recommendations, randomized and better standardized studies are needed, taking into account doses in milligrams of caffeine and contexts (age, comorbidities, concomitant substances).

Source: Low CE et al. Association of Coffee and Energy Drink Intake with Suicide Attempts and Suicide Ideation: A Systematic Review and Meta-Analysis. Nutrients. 2025;17(11):1911. https://doi.org/10.3390/nu17111911