Response to drugs is influenced by psychological factors

To gain FDA approval a drug has to be shown to be better than a placebo. The placebo effect is a well-established psychological contributor to the efficacy of most treatments.

A group of Italian researchers just published an interesting study looking at other psychological factors that might influence the response to treatment.

They evaluated chronic migraine patients who were treated with erenumab (Aimovig). Erenumab is a monoclonal antibody that targets CGRP, a neurotransmitter involved in the development of migraine attacks.

Monthly erenumab injections were given for one year to 75 patients with chronic migraine who had already failed at least three other oral preventive drugs. A full psychological evaluation assessed personality disturbances, mood and anxiety disorders, as well as childhood traumas, and ongoing stressors.

After 12 months of treatment, 53 patients had at least a 50% drop in the number of headache days per month. The other 22 did not. When compared to responders, non-responders were more likely to have personality disorders with anxious-fearful, avoidant, dependent, and obsessive-compulsive features. Non-responders were also more likely to suffer anxiety disorders and had a higher number of current major stressors.

A very practical application of these findings is that doctors need to address anxiety when treating migraine and chronic pain patients. I’ve seen a number of patients whose migraines improved with an SSRI antidepressant such as fluoxetine (Prozac) or escitalopram (Lexapro). SSRIs do not possess pain-reliving properties. However, they are good at relieving anxiety and so can indirectly improve migraines. Most of the time, I prescribe SNRIs such as duloxetine (Cymbalta) or a tricyclic antidepressant such as nortriptyline (Pamelor) because they relieve anxiety and can have a direct pain-relieving effect.

The old dogma in psychology was that you cannot change your personality. We now know that such change is possible. Different types of cognitive-behavioral therapy (CBT) can be very helpful. Swedish researchers showed that even a brief internet-based CBT can produce long-term changes in personality traits.