Acoustic Startle Reduction In Cocaine Dependence

Chronic cocaine administration leads to changes in brain function that persist long after the acute withdrawal phase. The acoustic startle response (ASR) is a well characterized reflexive response to a sudden acoustic stimulus. The ASR is mediated by a simple 3-synapse subcortical circuit; it is modulated in part by brain areas and neurotransmitters associated with cocaine administration. Our initial study and subsequent replication reveals a profound diminution of the ASR in cocaine-dependent subjects after a brief period of abstinence. Our preliminary findings indicate that first degree relatives of cocaine-dependent subjects also have reduced startle compared to healthy controls. The findings of low ASR in rats and humans during cocaine washout and low ASR in family members suggests there may be both a trait and state component of the startle reductions we have reported.

The central objectives of this proposal are to dissect this finding with regard to its development and persistence in early and later phases of cocaine abstinence in humans; to ascertain whether startle reduction and its potential normalization during later abstinence is a predictor of clinical course in human subjects with cocaine dependence; and to examine whether startle reduction is, at least in part, a vulnerability trait for the development of cocaine dependence. This latter Aim will be carried out in humans by testing siblings of cocaine-dependent subjects.

Cocaine dependence is an enormous public health problem. The significance of this work lies in the potential for the ASR reduction to serve as a reliable, easily repeatable biological measure of cocaine-induced brain changes that may enhance outcome prediction so that tailored treatments may be directed at those patients most vulnerable to relapse, given the restriction of resources for available for substance abuse treatment.

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Key information

Conditions

Cocaine-Related Disorders Chemically-Induced Disorders Mental Disorders Substance-Related Disorders

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Atlanta Veterans Adminstration Medical Center

Decatur, Georgia, 30033, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Cocaine dependent subjects:

males or females,
age 18-80,
with a DSM-IV diagnosis of cocaine dependence,
a usage history characterized by a minimum of 1 year of at least $50 per day or weekly binges of at least $200 of cocaine use.

Exclusion criteria

current clinically significant medical illness (including HIV, because of possible confound of neurological involvement),
current or past neurological illness, and no history of head trauma with loss of consciousness ≥ 5 minutes because of the possible confound of neurological damage to startle-modulating brain areas,
other Axis I psychiatric disorder currently or in the previous three months with the exception of substance induced disorders as determined by SCID,
history of schizophrenia, schizoaffective disorder, posttraumatic stress disorder, or bipolar disorder,
known hearing impairments (intact hearing will be insured by brief audiology screening),
dependence on other drugs or alcohol within the previous 6 months, as confirmed by ASI.

Healthy controls:

males or females,
age 18-80.

Exclusion criteria

history of any Axis I psychiatric illness or history of treatment as determined by SCID Axis I,
substance dependence or abuse history by ASI and SCID,
no current clinically significant medical illness (including HIV),
current or past neurological illness, or history of head trauma with loss of consciousness ≥ 5 minutes because of the possible confound of neurological damage to startle-modulating brain areas,
known hearing impairments (intact hearing will be insured by brief audiology screening),
Axis I disorder, including substance dependence, in first degree family member.

Family members of cocaine subjects:

males or females,
age 18-80,
family member of cocaine-dependent subject enrolled in study.

Exclusion criteria

history of any Axis I psychiatric illness or history of treatment as determined by SCID Axis I,
substance dependence history by ASI and SCID, or substance abuse within the prior 5 years,
no current clinically significant medical illness (including HIV),
current or past neurological illness, or history of head trauma with loss of consciousness,
known hearing impairments

Treatment and study plan

acoustic startle testing

Procedure

acoustic startle testing: listening to sounds through headphones while the eyeblink component of the acoustic startle reflex is recorded with small surface electrodes

Primary outcomes

Acoustic startle magnitude

Time frame: at baseline

Magnitude of acoustic startle response as measured by electromyography of eyeblink.

Sponsors and collaborators

Lead sponsor

Emory University

Other

Collaborators

National Institute on Drug Abuse (NIDA)

Registry information

Important dates

Study start: 2006
Primary completion: 2011
Study completion: 2011
First posted: Feb 2, 2007
Registry last updated: Aug 7, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

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