Relationship of Alexithymia Ratings to Dopamine D2-type Receptors in Anterior Cingulate and Insula of Healthy Control Subjects but Not Methamphetamine-Dependent Individuals

Kyoji Okita; Dara G Ghahremani; Doris E Payer; Chelsea L Robertson; Mark A Mandelkern; Edythe D London

doi:10.1093/ijnp/pyv129

Relationship of Alexithymia Ratings to Dopamine D2-type Receptors in Anterior Cingulate and Insula of Healthy Control Subjects but Not Methamphetamine-Dependent Individuals

Int J Neuropsychopharmacol. 2016 Apr 29;19(5):pyv129. doi: 10.1093/ijnp/pyv129. Print 2016 May.

Authors

Kyoji Okita¹, Dara G Ghahremani¹, Doris E Payer¹, Chelsea L Robertson¹, Mark A Mandelkern¹, Edythe D London²

Affiliations

¹ Department of Psychiatry and Biobehavioral Sciences (Drs Okita, Ghahremani, and London), Department of Molecular and Medical Pharmacology (Drs Robertson and London), and Brain Research Institute (Dr London), University of California Los Angeles, Los Angeles, CA; Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario, Canada (Dr Payer); Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada (Dr Payer); Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA (Drs Okita, Robertson, Mandelkern, and London); Department of Physics, University of California Irvine, Irvine, CA (Dr Mandelkern).
² Department of Psychiatry and Biobehavioral Sciences (Drs Okita, Ghahremani, and London), Department of Molecular and Medical Pharmacology (Drs Robertson and London), and Brain Research Institute (Dr London), University of California Los Angeles, Los Angeles, CA; Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario, Canada (Dr Payer); Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada (Dr Payer); Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA (Drs Okita, Robertson, Mandelkern, and London); Department of Physics, University of California Irvine, Irvine, CA (Dr Mandelkern). [email protected].

Abstract

Background: Individuals with substance-use disorders exhibit emotional problems, including deficits in emotion recognition and processing, and this class of disorders also has been linked to deficits in dopaminergic markers in the brain. Because associations between these phenomena have not been explored, we compared a group of recently abstinent methamphetamine-dependent individuals (n=23) with a healthy-control group (n=17) on dopamine D2-type receptor availability, measured using positron emission tomography with [(18)F]fallypride.

Methods: The anterior cingulate and anterior insular cortices were selected as the brain regions of interest, because they receive dopaminergic innervation and are thought to be involved in emotion awareness and processing. The Toronto Alexithymia Scale, which includes items that assess difficulty in identifying and describing feelings as well as externally oriented thinking, was administered, and the scores were tested for association with D2-type receptor availability.

Results: Relative to controls, methamphetamine-dependent individuals showed higher alexithymia scores, reporting difficulty in identifying feelings. The groups did not differ in D2-type receptor availability in the anterior cingulate or anterior insular cortices, but a significant interaction between group and D2-type receptor availability in both regions, on self-report score, reflected significant positive correlations in the control group (higher receptor availability linked to higher alexithymia) but nonsignificant, negative correlations (lower receptor availability linked to higher alexithymia) in methamphetamine-dependent subjects.

Conclusions: The results suggest that neurotransmission through D2-type receptors in the anterior cingulate and anterior insular cortices influences capacity of emotion processing in healthy people but that this association is absent in individuals with methamphetamine dependence.

Keywords: Methamphetamine dependence; PET; alexithymia; dopamine; emotion processing.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Affective Symptoms / metabolism*
Affective Symptoms / physiopathology
Affective Symptoms / psychology
Amphetamine-Related Disorders / metabolism*
Amphetamine-Related Disorders / physiopathology
Amphetamine-Related Disorders / psychology
Benzamides / administration & dosage
Case-Control Studies
Central Nervous System Stimulants / adverse effects*
Cerebral Cortex / chemistry
Cerebral Cortex / drug effects*
Cerebral Cortex / physiopathology
Emotions / drug effects*
Female
Gyrus Cinguli / chemistry
Gyrus Cinguli / drug effects*
Gyrus Cinguli / physiopathology
Humans
Magnetic Resonance Imaging
Male
Methamphetamine / adverse effects*
Middle Aged
Positron-Emission Tomography
Pyrrolidines / administration & dosage
Radiopharmaceuticals / administration & dosage
Receptors, Dopamine D2 / analysis*
Synaptic Transmission
Young Adult

Substances

Benzamides
Central Nervous System Stimulants
DRD2 protein, human
N-((1-allyl-2-pyrrolidinyl)methyl)-5-(3-fluoropropyl)-2,3-dimethoxybenzamide
Pyrrolidines
Radiopharmaceuticals
Receptors, Dopamine D2
Methamphetamine

Abstract

Publication types

MeSH terms

Substances

Grants and funding