Substance use disorder comorbidity with schizophrenia in families of Mexican and Central American Ancestry
Received 14 October 2009; received in revised form 8 February 2010; accepted 15 February 2010. published online 22 March 2010.
Abstract
Objectives
The aims of this study were to estimate the frequency and course of substances use disorders in Latino patients with schizophrenia and to ascertain risk factors associated with substance use disorders in this population.
Method
We studied 518 subjects with schizophrenia recruited for a genetic study from the Southwest United States, Mexico, and Central America (Costa Rica and Guatemala). Subjects were assessed using structured interviews and a best estimate consensus process. Logistic regression, χ2, t test, Fisher's exact test, and Yates' correction, as appropriate, were performed to assess the sociodemographic variables associated with dual diagnosis. We defined substance use disorder as either alcohol or substance abuse or dependence.
Results
Out of 518 patients with schizophrenia, 121 (23.4%) had substance use disorders. Comorbid substance use disorders were associated with male gender, residence in the United States, immigration of Mexican men to the United States, history of depressive syndrome or episode, and being unemployed. The most frequent substance use disorder was alcohol abuse/dependence, followed by marijuana abuse/dependence, and solvent abuse/dependence.
Conclusion
This study provides data suggesting that depressive episode or syndrome, unemployment, male gender, and immigration of Mexican men to the United States were factors associated with substance use disorder comorbidity in schizophrenia. Binary logistic regression showed that country of residence was associated with substance use disorder in schizophrenic patients. The percentage of subjects with comorbid substance use disorders was higher in the Latinos living in the United States compared with subjects living in Central America and Mexico.
aSouth Texas Psychiatric Genetics Research Center, Paul L. Foster School of Medicine, Texas Tech University Health Science Center, San Antonio, TX, United States
bCentro Investigación en Biología Molecular y Celular, University of Costa Rica, San José, Costa Rica
cDepartment of Psychiatry, South Texas Veterans Health System, San Antonio, San Antonio, TX, United States
dGrupo de Estudios Médicos y Familiares Carraci S.C., México DF., Mexico
eDepartment of Psychiatry and Biobehavioral Science, University of California, Los Angeles Medical Center, United States
fInstituto de Información e Investigación en Salud Mental, Monterrey, Mexico
gCentro de Investigaciones Biomédicas, Guatemala City, Guatemala
hDepartment of Psychiatry, University of California, San Diego, CA, United States
iDepartment of Psychiatry, Paul L. Foster School of Medicine, Texas Tech University Health Science Center, El Paso, TX, United States
jNeuroscience Center of Excellence, Paul L. Foster School of Medicine, Texas Tech University Health Science Center, El Paso, TX, United States
Corresponding author. Neuroscience Center of Excellence, Paul L. Foster School of Medicine, Texas Tech University Health Science Center, 5001 El Paso Drive, El Paso, TX 79905, United States. Tel.: +1 915 545 6831; fax: +1 210 562 5114.
ABSTRACT