A major analysis involving over 11,000 adults with a history of depression has found that consuming high amounts of caffeine is associated with greater psychological distress and elevated stress levels, according to a report in PsyPost on May 28.
Led by University of Queensland researcher Harry McIntosh, the study used data from the Australian Genetics of Depression Study. Researchers categorized participants into low (0–2), medium (3–5), and high (6+ caffeinated beverages per day) consumption groups—including coffee, tea, energy drinks, and sodas. Individuals who consumed six or more servings daily scored significantly higher on the standardized Kessler Psychological Distress Scale, with each extra drink raising distress scores by 0.2 points on the 50‑point scale.
Interestingly, while heavy caffeine intake marginally affected sleep satisfaction, the effect wasn’t statistically significant after adjusting for variables such as age, BMI, alcohol, nicotine, and painkiller use. This suggests stress and mood effects linked to caffeine are not solely mediated by poor sleep.
Genetic analysis revealed that common DNA variants influence both caffeine intake and psychological response. For instance, variations in the CYP1A2 gene—responsible for caffeine metabolism—were tied to consumption levels, while sensitivity to caffeine correlated with decreased intake .
McIntosh emphasized the study’s limitations and implications: “We cannot assign a causal relationship because participants may increase caffeine consumption in response to symptoms of depression such as fatigue or lack of motivation”. Nonetheless, the research suggests reducing caffeine may be a practical strategy for individuals with depression to help lower stress.
These findings align with broader scientific literature linking caffeine to worsened mental health indicators, particularly among sensitive populations. Reviews of energy drink use and youth consumption support positive associations between high caffeine intake and increases in stress, anxiety, and depressive symptoms.
