A DOUBLE ESTRESSO
Warning: Your daily coffee is a powerful drug and can even spark panic attacks
CAFFEINE is a drug most of us take daily. For at their essence, tea and coffee are simply convenient, stigma-free vessels for funnelling caffeine into our bodies. You may think that is fantastic – an easy, cheap way to rev up your day – but research shows we massively underestimate the drug’s effects on our bodies and brains.
It is an extremely powerful, psychoactive substance. In moderation, it makes us feel good. In excess, it is unpleasant, and in large enough doses it can even be fatal. While a 16th of a teaspoon of pure caffeine powder gives a solid boost to a regular user, raising that to just a quarter teaspoon will lead to unpleasantness – racing heart, sweating, acute anxiety.
And it is this latter side effect that is particularly concerning, given the soaring incidence of worry and depression. One adult in 20 now suffers anxiety, a feeling of unease or fear that can be mild or severe. The medical term is generalised anxiety disorder and it affects about three million people in the UK.
At the same time we have a national obsession with tea, coffee and energy drinks, yet few of us stop and think about the impact of caffeine on our minds.
That energy kick alters the brain – and it works hard and fast.
Caffeine is unusually mobile in the body; the small molecule reaches the brain in just 20 minutes and easily hurdles the blood-brain barrier. Once there, it blocks the uptake of adenosine, a neurotransmitter that tells the brain we are drowsy.
This simple trick prevents us from feeling tired – suddenly no task seems insurmountable.
But caffeine also has physiological effects – it stimulates your central nervous system so your alertness increases, reaction time decreases and focus sharpens. Your blood pressure will increase slightly, your heart may race: all symptoms commonly associated with anxiety.
So while those physiological changes come together to give many of us a reliable boost, caffeine can have serious psychological effects.
And it’s not just a problem for people particularly susceptible to caffeine.
John Greden, of the University of Michigan, says too much caffeine can make almost anyone anxious.
In his paper Anxiety Or Caffeinism: A Diagnostic Dilemma, he points out that it’s often overlooked that ‘high doses of caffeine – or “caffeinism” – can produce pharmacological actions that cause symptoms essentially indistinguishable from those of anxiety neuroses’.
Greden has encountered cases such as a 27-year-old nurse who complained of lightheadedness, tremulousness, breathlessness, headache and irregular heartbeat. She was first diagnosed with an anxiety reaction but later discovered the cause was coffee.
She had been consuming an average of ten to 12 cups of strong black coffee a day. Once she withdrew from drinking coffee, her symptoms vanished. Other subjects had similar symptoms on 14 cups of coffee a day and once caffeine intake was reduced, symptoms improved dramatically.
Clearly, these are extreme examples. Most people stop at three or four cups of coffee daily.
But they illustrate an important point: while many people complaining of anxiety benefit from psychopharmacological agents, for others, subtracting one drug – caffeine – may be of greater benefit.
So the ideal first-line treatment for anxiety in a patient who uses caffeine is to eliminate it and see how he or she responds, before prescribing anti-anxiety medication.
Bizarrely, there is a genetic predisposition to caffeine-induced psychological effects, such as acute anxiety and even panic attacks. Research shows some people are more susceptible due to differences in their adenosine receptors. This helps explain why some people have no trouble sleeping after coffee late at night, while others lie awake for hours after an afternoon cup of tea. Caffeine is also associated with panic attacks, in which people feel they are losing control and that something horrible is happening. The attacks are transient, but can be utterly debilitating and are remarkably common.
A study published in 2007 looked at three distinct groups: a control group of healthy people with no history of panic disorder, people with a history of panic disorder, and first-degree relatives of the panic-disorder group who had no history of panic attacks. Subjects were given decaffeinated or high-caffeine coffee (equivalent to six Red Bulls or 1.2 litres of moderately strong coffee). None had panic attacks or increased anxiety after the decaf. But 52 per cent of the panic-disorder patients suffered a panic attack after the caffeinated coffee.
The unexpected finding was that 41 per cent of the first-degree relatives of the panic-disorder patients also suffered panic attacks.
They had no history of panic attacks, and yet one strong dose of caffeine induced an attack – showing not only that some people have a genetic predisposition to caffeine-induced anxiety, but the very real, very distressing impact caffeine can have. Research has shown it can even induce hallicunations.
Australian researchers studied the combination of stress and caffeine in a group with no psychiatric problems and found that high caffeine levels in association with elevated levels of stressful life events interacted to produce higher levels of ‘hallucination’ in nonclinical participants.
You may not want to think that your comforting drink could be anything but.
Yet any caffeine user who believes that it’s totally benign should try going without it for a few days. Withdrawal often includes headaches, muscle pain, weariness, apathy and depression.
Our love affair with caffeine is unlikely to end. But we need to remember that it is a complicated drug and can affect us in
strange ways.