Though alcohol craving is a long recognized phenomenon, there has been growing recognition of the clinical salience and utility over the past generation, particularly in the domains of diagnosis and intervention. Broadly defined, craving is a strong desire or urge to use a substance. However, much remains to be explored in this critical phenotype as theories regarding development and methodologies regarding assessment are highly variable.
Assessment of alcohol craving has long been an area of debate, which is investigated in Study 1. A number of measures have been developed to assess alcohol craving, which are frequently used interchangeably. Measures of craving are designed to either assess longer-term, unprovoked tonic or in the moment, provoked phasic craving. Little is known about the relationship between these types of craving. Thus, this study fills a gap in the existing literature to examine the association of tonic and phasic craving when alcohol craving is provoked by alcohol administration in a sample of individuals with an alcohol use disorder. Results indicated that tonic craving is predictive of phasic craving in the laboratory, particularly when alcohol is ingested, and that different measures of tonic craving may be capturing unique aspects of the craving experience.
In Study 2, the factor structure and diagnostic conversion of alcohol use disorders (AUD) to the Diagnostic and Statistical Manual-5 (DSM-5) from DSM-IV is examined. The DSM-5 included two major modifications: the legal criterion was dropped in favor of the addition of craving and the distinct syndromes of abuse and dependence were replaced with a single dimensional syndrome with severity specifiers. Non-treatment seeking alcohol users completed a structured clinical interview and the Penn Alcohol Craving Scale (PACS). PACS scores were used as a stand-in for the craving criterion with scores greater than 20 were considered to meet diagnostic criteria for craving. Overall, few participants (16.2%) were met the criterion using this cut-off score. Despite the low endorsement, craving loaded well onto the existing symptoms and supported the structural change of creating a unidimensional syndrome for AUD. Though prevalence did slightly increase in the sample when converted to DSM-5, this was due to the structural change as opposed to the addition of craving. Implications for a non-treatment seeking sample are discussed.
Study 3 is an exploratory examination of the role the alpha-synuclein (SNCA) gene plays in predicting alcohol craving. Using previous literature, two single nucleotide polymorphisms (SNP) rs356219 and rs356221 and their haplotype were identified to investigate as predictive of alcohol craving. The sample was Caucasian and Hispanic problem alcohol users from the community. Despite the theory driven approach to identify the genotype of interest, hypotheses were not supported. Neither the haplotype nor either SNP predicted alcohol craving as assessed by the PACS, OCDS, or either subscale, save for a trend level effect of one SNP predicting the Obsessive subscale of the OCDS. Additionally, the haplotype did not predict DSM-IV alcohol dependence. It is possible this study did not replicate prior work due to the heterogeneity of alcohol users and general low levels of craving endorsed.
Together, these studies met the aim of this dissertation to better characterize and explore the phenotype of alcohol craving. These studies inform the literature by examining clinical, diagnostic, assessment and genetic components. Ultimately, improving characterization and assessment of this phenotype is critical to advance understanding of craving in order to improve diagnosis and intervention.