We Have Analyzed Over 1K Studies, and Here’s What We Found Out About Coffee Drinking and People with Mental Illnesses and Psychiatric Disorders

Coffee Geek Lab / We Have Analyzed Over 1K Studies, and Here’s What We Found Out About Coffee Drinking and People with Mental Illnesses and Psychiatric Disorders
Yurii Brown

Certified Barista

December 3, 2021

There’s a lot of controversy around coffee consumption, especially when it comes to people with mental health issues, as caffeine has both drawbacks and advantages.

We wanted to dig deeper into the question of coffee and mental health to see how this beverage may affect people with different conditions.

Today’s report will sum up over 1K studies and research papers, sharing the key statistics concerning caffeine consumption and mental illnesses. Hopefully, it can give readers a better understanding of how safe or unsafe coffee is for people with mental health difficulties.

Our Findings

  • Drinking coffee regularly can reduce the risk of suicide in both men and women by around 50% (1).
  • Drinking coffee can prevent or decrease the risk of Alzheimer’s disease in older patients (2).
  • Coffee can alleviate OCD symptoms by up to 12% (3).
  • People with schizophrenia are more likely to drink more coffee than patients with other mental disorders (4).
  • Healthy doses of caffeine can alleviate depression symptoms (5). 
  • Coffee has a stronger effect (both positive and negative) on people with anxiety, as this condition makes patients more sensitive to caffeine (6). 
  • Too much coffee can strengthen schizophrenia symptoms, particularly delusions and hallucinations (7).
  • Caffeine can aggravate the negative consequences of anorexia nervosa (8).
  • Coffee consumption can aggravate insomnia in people suffering from mental illnesses (9). 
  • People suffering from eating disorders are likely to drink more coffee than patients with other mental issues (10). 
  • In healthy people, caffeine can lower the risk of developing certain disorders, including Alzheimer’s, Parkinson’s disease, and depression (11) (12) (13).

Coffee Drinkers Are About 50% Less Likely to Commit Suicide

More than 90% of adults in the United States consume caffeine regularly (14). With these numbers in mind, we have to account for both the positive and negative effects of caffeinated beverages. After all, coffee and mental health are connected and may have a bidirectional relationship.

Now, many studies show that the benefits of coffee outweigh the side effects, especially when it comes to healthy amounts of caffeine (up to 400 mg per day) (15). For instance, research suggests that people who drink coffee regularly are twice less likely to commit suicide

The thing is, caffeine does not just affect the central nervous system and cause alertness. It can also act as a mild antidepressant, as this substance can boost the production of dopamine and serotonin. These hormones regulate mood, which may explain the connection between caffeine and decreased suicide risk.

This coffee and mental health study shows that the effect of caffeine in patients with mental health illnesses can be positive (especially in people with depression). However, this only refers to healthy doses of the substance. Too much coffee causes more dangerous side effects, so it is crucial for mental health patients to control their caffeine intake.

Drinking Coffee Can Ward Off Alzheimer’s In Older Patients

Caffeine not only affects one’s mood but may also influence brain function. That’s why we were interested in discovering the positive effects of coffee on patients with age-related cognitive impairments.

One study shows that plasma caffeine levels are 51% lower in older patients (mild cognitive impairment subjects) who later progressed to dementia. As a comparison, stable mild cognitive impairment subjects who experienced no conversion to dementia during the follow-up 2-4 years had higher levels of caffeine in their blood.

This leads to the conclusion that the coffee and mental health relationship should not be underestimated. Drinking healthy amounts of coffee can decrease one’s risk of developing Alzheimer’s disease even at an older age and when already facing mild cognitive impairment.

Drinking Coffee Can Help People Alleviate OCD Symptoms by Up to 12%

Obsessive-compulsive disorder (OCD) can be very debilitating, as it’s typically characterized by repeated thoughts, fears, anxious mental images, stress, and more (16). Many OCD patients are resistant to treatment, which makes their doctors turn to auxiliary tools.

And it turns out that coffee can be one of them. Caffeine and OCD can seem a contradictory combination (as coffee increases alertness). Nonetheless, studies show that caffeine can reduce some OCD symptoms by up to 12% in patients resistant to treatment.

The reason why caffeine and OCD can be a good pairing hides in the way coffee affects adenosine receptors. Caffeine can have an inhibitory role on them. It results in increased production of serotonin, tryptophan, dopamine, and other neurotransmitters involved in the pathophysiology of OCD. They are known to affect one’s mood, thinking abilities, energy, and fatigue, which explains how coffee may help alleviate some OCD symptoms. 

Moreover, dopamine production may help people with OCD shift their attention easier. Therefore, drinking coffee can reduce the number of obsessive thoughts that often accompany this condition. In other words, caffeine and intrusive thoughts don’t go hand in hand.

This research can provide doctors with additional tools when it comes to treating OCD, especially in patients who are resistant to common treatments.

People with Schizophrenia Tend to Consume Significantly More Coffee Than Other Patients

Some schizophrenia symptoms involve cognitive impairment and thinking issues (17). And as we already know, coffee can affect the brain, which means it may potentially influence those symptoms as well. We also know that caffeine and intrusive thoughts don’t “work” well together, and the latter may also be present in schizophrenia patients.

Since coffee may alleviate at least some symptoms of this condition, we can assume that schizophrenia patients often turn to this beverage. And research can back this up. It turns out that the daily consumption rates of caffeine in schizophrenia patients are almost two times higher than in the healthy population.

Additionally, 13% of people with schizophrenia consume over 1000 mg of caffeine daily (with the recommended maximum dose of 400 mg).

We can assume that high numbers of coffee drinkers among schizophrenia patients could mean that caffeine does alleviate some of the symptoms. This can again prove the effect of coffee on the brain, its ability to improve cognitive function, and the fact that coffee and mental health are often correlated.

Healthy Caffeine Doses Can Alleviate Depression Symptoms

It is already clear what effect caffeine has on dopamine levels (18).

And this effect is the reason why coffee can potentially alleviate symptoms in people with depression. The thing is, dopamine governs the brain’s motivation, reward, and mood circuits. Targeting them is one of the ways to treat depression.

Caffeine affects those circuits as well by boosting dopamine production. Thus, coffee can potentially alleviate some depression symptoms, especially motivation- and mood-related ones.

It’s also worth mentioning that caffeine consumption can lower the risk of developing depression in healthy individuals. This, again, proves how beneficial coffee can be for one’s mental health (if consumed in healthy amounts).

Coffee May Have a Stronger Effect on People with Anxiety, Especially When It Comes to Harmful Consequences 

Caffeine influences different people in various ways, and its effect may depend drastically on one’s mental condition. Therefore, people with mental illnesses need to be aware of the coffee effects to protect themselves from unpleasant consequences. 

Research suggests that people suffering from anxiety are among the most susceptible to caffeine. Coffee has a stronger effect on them regarding both positive and negative outcomes. The former include enhanced focus and concentration (19), which can help anxious people stay functional at work or when dealing with daily tasks.

However, the adverse effects of caffeine on people with anxiety outweigh the benefits. For example, coffee can aggravate such symptoms as restlessness, worry, irritability, sleeplessness, etc. Drinking coffee may also trigger twitching or dizziness in anxiety patients. 

This research means that people with anxiety need to control their caffeine intake. Ideally, they can switch to decaf if they can’t give up drinking coffee. To make the transition easier, they can gradually decrease the amount of coffee consumed daily. 

Too Much Coffee Can Make Schizophrenia Symptoms Worse

It is clear that caffeine has a strong effect on the brain and hormonal regulation. That’s why it may also influence the symptoms of certain mental disorders. And considering the statistics of coffee consumption in schizophrenia patients, we need to draw attention to the possible consequences of caffeine intake.

Research suggests that drinking too much coffee may aggravate such schizophrenia symptoms as hallucinations and delusions. This has to do with the way caffeine alters dopaminergic activity at post-synaptic neurons in the brain. 

So, despite some of the positive effects of coffee (like improved mood and focus), schizophrenia patients should be very careful with this beverage. If they cannot abstain from caffeine, it’s crucial to keep its dosages moderate (up to 400 mg a day, which equals around 4 cups of regular drip coffee).

Caffeine’s Negative Effects Are Especially Dangerous for People Suffering From Anorexia Nervosa

People with anorexia are at high risk of cardiac arrhythmias, a dangerous heart condition that involves irregular heartbeat (20). It can potentially lead to heart failure and, thus, should be taken seriously. 

At the same time, anorexia patients need to remember that caffeine can have a stimulating effect on the heart. It often causes increased heart rate, which may aggravate cardiac arrhythmia. In other words, people with anorexia nervosa are more sensitive to caffeine and its effect on the heart.

Unfortunately, coffee consumption is not always assessed when monitoring mental health patients’ well-being. However, this research proves that the role of caffeine should not be ignored. It can also be a good indication for anorexia patients to limit their coffee consumption

Too Much Coffee Can Aggravate Disorder-Induced Insomnia 

Around 50% of all insomnia cases are linked to anxiety, depression, or chronic psychological stress (21). Other mental disorders also go hand in hand with sleep issues. Unfortunately, caffeine consumption can aggravate those problems further. 

Coffee is a brain stimulant. It blocks adenosine receptors that cause the feeling of drowsiness. That’s why caffeine can effectively combat the results of sleep deprivation and aid improved alertness. 

At the same time, that’s the reason why coffee can aggravate insomnia, a common companion of many mental disorders. And lack of sleep, in its turn, may harm such aspects of mental well-being as mood, ability to manage stress, anxiety, and more.

Therefore, people dealing with mental health issues need to take this research into account. If they experience sleep difficulties, reducing their caffeine intake might be a good idea. It’s also beneficial to drink coffee only during the first half of the day.

People Suffering From Eating Disorders Drink More Coffee

Research shows that caffeine abuse is more represented among people with eating disorders than the rest of the population. In other words, people suffering from eating disorders are more likely to overindulge in coffee, which can lead to dangerous side effects.

This can be explained by coffee’s ability to suppress appetite (22). However, by trying to control their appetite, people with eating disorders may end up experiencing the negative side effects of caffeine consumption. 

This research proves the importance of coffee intake assessment in mental health patients. Caffeine abuse is very common, so it should be accounted for when diagnosing and looking for optimal treatment options.

Coffee Can Prevent Depression, Parkinson’s, and Alzheimer’s

While we already have a clear understanding of how caffeine may affect certain mental conditions, it’s also worth mentioning that coffee can also prevent diseases.

Studies show that coffee’s effect on the brain and its cognitive functions is significant enough to reduce one’s chances of developing depression, Alzheimer’s, and Parkinson’s. For instance, 3-5 cups of coffee daily at midlife can decrease one’s chances of dementia and Alzheimer’s by about 65% later in life. Consuming healthy amounts of caffeine may also reduce the risk of developing Parkinson’s by up to 30%. 

Evidently, coffee can offer lots of benefits regarding one’s mental health. However, readers need to remember that we are talking about moderate, healthy caffeine doses. Overindulging in coffee can have significantly more negative consequences.


The effect of caffeine on mental health is undeniable. In some cases, it may alleviate unpleasant symptoms; in others – aggravate them. That’s why psychiatrists should assess coffee consumption alongside other lifestyle habits. And, of course, mental health patients need to be careful with this delicious beverage. It’s better to learn more about potential side effects for each mental disorder and build one’s coffee routine (and doses) accordingly.

How much coffee do you usually drink? Have you ever felt a significant effect on your mental state? Let us know in the comments!


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  2. Chuanhai Cao, David Loewenstein, Xiaoyang Lin, Chi Zhang, Li Wang, Ranjan Duara, Yougui Wu, Alessandra Giannini, Ge Bai, Jianfeng Cai, Maria Greig, Elizabeth Schofield, Raj Ashok, Brent Small, Huntington Potter, Gary Arendash (2012). High Blood caffeine levels in MCI linked to lack of progression to dementia. Retrieved from https://pubmed.ncbi.nlm.nih.gov/22430531/
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  9. Christopher Drake, Timothy Roehrs, John Shambroom, Thomas Roth (November 15, 2013). Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. Retrieved from https://jcsm.aasm.org/doi/10.5664/jcsm.3170
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