When I first learned of a putative association between a particular medication ( pramipexole (Requip)) I was reminded of a defense in a bank holdup in which the attorney for the defendant argued that Halcion made the person rob the bank.
I am less skeptical after reading the report from Mayo clinic and the series of letters to the editor that followed. Dodd et al reported 11 patients with pathological gambling who were taking pramipexole for Parkinson Disease (PD). Other dopamine agonists and levodopa have also been implicated. Also other compulsive behaviors have been described.
The authors postulated that the apparent greater prevalence with this particular agonist may be due to its greater effect on the D3 dopamine receptors in the limbic cortex. However, one letter challenged the excess dopamine theory by relating one case of compulsive gambling in a PD patient who was treated with deep brain stimulation of the subthalamic nucleus.
The theory is that with increased dopaminergic stimulation there is increasing loss of impulse control. Supporting this association between dopamine agonist and gambling is the reported reversal of the condition by discontinuing the medication.
A pathologist with PD from Texas has filed a law suit against the manufacturer of the medication.
Does all of this raise philosophical questions about free will ? Can a medication really make some one carry out the complicated acts such as are required to take part in repeated gambling? I would be interested in hearing some thoughts about that.