Effect of Exercise Training on Striatal Dopamine D2/D3 Receptors in Methamphetamine Users during Behavioral Treatment (2015)

COMMENTS: 8 weeks of exercise significantly increased D2 receptors in meth addicts undergoing treatment. This supports the following:

  1. Exercise can help reverse desensitization even in meth addicts.
  2. D2 receptor levels are not set in stone: environment matters.
  3. Meth use seems to cause a drop in D2 receptors. As with #2 this refutes the “you born to be an addict” meme.

Neuropsychopharmacology. 2015 Oct 27. doi: 10.1038/npp.2015.331.

Robertson CL1,2, Ishibashi K2,3, Chudzynski J3, Mooney LJ3, Rawson RA3, Dolezal BA4, Cooper CB4, Brown AK1,2, Mandelkern MA2, London ED1,2,3.

Abstract

Methamphetamine Use Disorder is associated with striatal dopaminergic deficits, which have been linked to poor treatment outcomes, identifying these deficits as an important therapeutic target. Exercise attenuates methamphetamine-induced neurochemical damage in the rat brain, and a preliminary observation suggests that exercise increases striatal D2/D3 receptor availability (measured as non-displaceable binding potential, BPND) in patients with Parkinson’s disease.

The goal of this study was to evaluate whether adding an exercise-training program to an inpatient behavioral intervention for methamphetamine use disorder reverses deficits in striatal D2/D3 receptors. Participants were adult men and women who met DSM-IV criteria for methamphetamine dependence and were enrolled in a residential facility, where they maintained abstinence from illicit drugs of abuse and received behavioral therapy for their addiction.

They were randomized to a group that received 1-hr supervised exercise training (n=10) or one that received equal-time health-education training (n=9), 3 days/week for 8 weeks.

They came to an academic research center for positron emission tomography (PET) using 18F-fallypride to determine the effects of the 8-week interventions on striatal D2/D3 receptor BPND.

At baseline, striatal D2/D3 BPND did not differ between groups. However, after 8-weeks, participants in the exercise group displayed a significant increase in striatal D2/D3 BPND, while those in the education group did not. There were no changes in D2/D3 BPND in extrastriatal regions in either group.

These findings suggest that structured exercise training can ameliorate striatal D2/D3 receptor deficits in methamphetamine users, and warrants further evaluation as an adjunctive treatment for stimulant dependence.Neuropsychopharmacology accepted article preview online, 27 October 2015. doi:10.1038/npp.2015.331.