Craving Is Associated with Amygdala Volumes in Adolescent Marijuana Users During Abstinence

Amygdala volume abnormalities have been reported in relation to craving in substance-dependent adults, but it remains unclear if these effects are seen in adolescent marijuana (MJ) users, particularly following abstinence.

The aim of this study was to examine the relationship between amygdala volume and craving during 28 days of abstinence in adolescent MJ users.

MJ-using adolescents (n = 22) aged 16–19 were recruited as part of a larger study on brain function in teen drug users. Craving measures were collected twice per week throughout a 28-day abstinence period. High-resolution anatomical magnetic resonance imaging data were collected at the end of the 28 days of confirmed abstinence. Left and right amygdala volumes were traced by hand (ICC>0.86). Composite scores for self-reported craving and withdrawal symptoms throughout the 28-day abstinence period were calculated to provide four composite measures of total craving, mood, sleep, and somatic complaints.

Results revealed that greater craving during abstinence was significantly associated with smaller left and right amygdala volumes, after controlling for age and gender. Other measures of withdrawal, including mood, somatic complaints and sleep problems, were not related to amygdala morphometry.

These results are consistent with previous findings in adult alcohol-and cocaine-dependent individuals, who demonstrated a relationship between reduced amygdala volumes and increased craving. 

Future studies are needed to determine if these brain-behavior relationships are attributable to MJ use or predate the onset of substance use.

Below:  Scatterplot of craving symptom scores predicting right and left amygdala to intracranial volume ratios in 22 abstinent adolescent marijuana users

Below:  Average craving rating for chronic marijuana users across nine time-points collected over 28 days of abstinence

Read more at: http://ht.ly/SshDS 

By: Claudia B. Padula, PhD,1 Tim McQueeny, MA,2 Krista M. Lisdahl, PhD,3 Jenessa S. Price, PhD,4 and Susan F. Tapert, PhD5

1Veterans Affairs Palo Alto Health Care System, Sierra Pacific Mental Illness Research Education and Clinical Center and Stanford University, Department of Psychiatry and Behavioral Sciences, Palo Alto, CA

2University of Cincinnati, Department of Psychology, Cincinnati, OH

3University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI

4McLean Hospital – Harvard Medical School, Department of Psychiatry, Belmont, MA

5Veterans Affairs San Diego Healthcare System and University of California, San Diego, Department of Psychiatry, La Jolla, CA