Obsessive compulsive disorder is an anxiety condition that, left untreated, can be quite debilitating. Nearly half the patients with OCD don’t get sufficiently better with psychotherapy or currently available medications. Based on old data that suggests it might be efficacious, our group conducted a study to test the ADD stimulant d-amphetamine (brand name: “Dexedrine”) in the treatment of OCD.
We recruited 24 OCD patients who had failed multiple drugs, and randomly assigned them to receive 30 mg of Dexedrine or 300 mg of caffeine every morning. Caffeine was chosen because its stimulant quality made its side effects similar to Dexedrine’s. As a result, neither doctor nor patient could “guess” who was taking what, and our assessments could not be influenced by knowledge of what drug the patient was receiving. Our hypothesis, of course, was that Dexedrine-treated patients would improve, whereas those on caffeine would not. The results took us by surprise.
Six of 12 patients taking Dexedrine and seven of 12 patients taking caffeine improved significantly. Their improvement was immediate—very uncommon in OCD—and was sustained for the five-week duration of the study. Contrary to what we had hypothesized, Dexedrine was not more effective. Caffeine worked just as well, if not slightly better.
It is hard to attribute our results to the “placebo effect”: Unlike depression where the placebo response rate can be high, the placebo effect in OCD is minimal and would not, alone, explain the 50 and 60% response rates we saw with Dexedrine and caffeine. Also, the improvement was sustained and did not diminish with time as often happens with placebo response. A better explanation could be that both drugs improved patients’ attention, which might have helped them shift their focus away from distracting obsessions and compulsions. Dopamine, a neurotransmitter involved in attention and that both Dexedrine and caffeine release in the brain, may be the common link.
One question, however, begs to be asked: If truly helpful in OCD, how could caffeine, a most ubiquitous substance, have not yet been observed to be beneficial? The answer might be dosing: Study patients took 300 mg tablets of caffeine every morning, or the equivalent of three cups of coffee drunk consecutively. This can produce a higher peak concentration in the blood than the consumption of several caffeinated beverages over the course of an entire morning. If a certain threshold concentration is required for clinical improvement to happen, it might not be reached with slow, “spread out” dosing. Still, caffeine is a well known anxiety producer in many people, and larger studies are needed before anyone can recommend it (or Dexedrine, for that matter) as a routine treatment for OCD. When at Starbucks, anxious individuals would still be well advised to opt for decaf.
