Adjunctive Behavior Research Articles

STAT: schema therapy for addiction treatment, a proposal for the integrative treatment of addictive disorders.

The nature and origins of addictions and of their adjunctive behaviors, as well as their chronicity, call for treatments that conceptualize and treat them as the long-term and complex processes that they are. Addictions are often comorbid with personality problems and with trauma histories. Patients suffering from these disorders often show poor engagement with treatment and high rates of relapse, possibly because available treatments have yet to address the patient suffering from addiction in a more integrated or holistic manner. In particular, comprehensive treatment models for addictive disorders - like treatments for personality disorders or trauma - are likely to require the integration of behavioral, cognitive, and emotion-focused interventions within a facilitative therapeutic relationship. However, most current treatment models, including ones which are highly effective in stabilization or behavioral change, lack one or more components of treatment that could sustain longer term recovery, wellness, and health for a higher percentage of patients. In this article, I propose approaching addictions and their treatment from the perspective of schema therapy, an integrative, developmental model with a strong track record of positive outcomes in addressing personality disorder symptoms and long-standing trauma histories, commonly comorbid with addictive disorders. In advancing this proposal, I begin by providing some background tying together addictions, attachment, and personality, suggesting they be treated simultaneously to achieve improved outcomes. Then, after briefly reviewing the leading approaches to the treatment of addictions, I introduce the idea that schema therapy is well-situated - both theoretically and practically - to address many of the shortcomings of existing treatment options. In particular, I note how addictive and co-occurring colluding behaviors are deeply intertwined with both early and continued frustration of core developmental needs. I illustrate how the addictive cycle is perpetuated through the process of schema reinforcement and through the operation of schema modes. I then demonstrate how these key terms (i.e., needs, schemas, and modes) inform the patient's assessment and case formulation, guiding treatment interventions from a strong therapeutic relationship that focuses on integrating recovery behavior change, healing dysfunctional schemas and modes, and preventing relapse.

Sustained-release drug delivery systems.

The design and development of a sustained-release drug delivery system targeting the administration of active pharmaceutical ingredients (APIs) to the eye could overcome the limitations of topically administered eye drops. Understanding how to modify or design new materials with specific functional properties that promote the attachment and release of specific drugs over longer time periods, alongside understanding clinical needs, can lead to new strategic opportunities to improve treatment options. In this paper we discuss two approaches to the design or modification of materials to produce a sustained therapeutic effect. Firstly, we discuss how the synthesis of a peptide hydrogel from a naturally-derived antimicrobial material led to the design of a bandage contact lens which may be able to be used prophylactically to reduce post-surgery infection. Secondly, we discuss how silicone oil tamponade agents used to treat retinal detachments can have adjunctive behaviour to enhance the solubility of the anti-proliferative drug retinoic acid and produce a sustained release over several weeks. These studies are the result of close partnerships between clinical ophthalmologists, materials scientists, and chemists, and illustrate how these partnerships can lead to comprehensive understandings that have the potential to change patient outcomes.

Addictive Behavior and Evolutionary Adaptation: Mitigated through Genetic Addiction Risk Severity Early Identification and Awareness Integration Theory

Objectives: Humans, with their unique genetic profile, exhibit a greater propensity to develop and maintain addiction compared to other animals. This paper offers a detailed examination of addiction, co-occurring traits, and psychologic disorders, focusing on neurobiological and molecular aspects. Furthermore, the authors investigate the potential of the Awareness Integration Theoretical model as an effective therapeutic addiction treatment. Methods: Using PsychINFO, PubMed, and Google Scholar, a comprehensive literature review was conducted on the evolutionary and adaptation pathways to addiction, epigenetic factors, and the potentiality of Awareness Integration Theory in treating addiction. Results: Epigenetics allows environmental factors to create lasting and heritable phenotypic changes, enabling rapid adaptation to these stimuli. Addiction “high-jacks” this system and the neurochemical mechanisms that control flexibility and innovation and is, thus, the price we pay for adaptability. Drug addiction is thought of as an adjunctive behavior or a subordinate behavior catalyzed by more profound, more significant psychological and biological stimuli. Conclusions: The neurochemical mechanisms underlying addiction, a complex interplay of genetic and environmental factors, are intertwined with the hallmark features of the human species, such as behavioral flexibility and pre-addictive propensity. The dopaminergic system, a key player in addiction, serves as a crucial link between addiction and the shared genetic profile evident in co-occurring traits and psychiatric and psychological disorders. Furthermore, a hypofunctioning dopaminergic system is a common characteristic of addiction and co-occurring psychiatric and psychological disorders. Early childhood preventative measures are vital in re-directing the existing predictive and poor adaptability functioning, which refers to the individual's inability to adapt to changing circumstances and reliance on maladaptive coping strategies. Awareness Integration Theory’s approach encompasses a therapeutical model addressing individuals' physical, cognitive, and psychosocial domains, allowing the individual to address intergenerational and ancestral ineffective and harmful adaptability. This, in turn, AIT will allow the human genome to be on a healthier path to recovery from obstacles such as addiction. When a tendency or a characteristic improves your ability to function and survive, and especially your ability to produce and raise children, that will most likely break the cycle of addiction and addictive behavior.

The development of compulsive coping behavior depends on dorsolateral striatum dopamine-dependent mechanisms

Humans greatly differ in how they cope with stress, a natural behavior learnt through negative reinforcement. Some individuals engage in displacement activities, others in exercise or comfort eating, and others still in alcohol use. Across species, adjunctive behaviors, such as polydipsic drinking, are used as a form of displacement activity that reduces stress. Some individuals, in particular those that use alcohol to self-medicate, tend to lose control over such coping behaviors, which become excessive and compulsive. However, the psychological and neural mechanisms underlying this individual vulnerability have not been elucidated. Here we tested the hypothesis that the development of compulsive adjunctive behaviors stems from the functional engagement of the dorsolateral striatum (DLS) dopamine-dependent habit system after a prolonged history of adjunctive responding. We measured in longitudinal studies in male Sprague Dawley rats the sensitivity of early established vs compulsive polydipsic water or alcohol drinking to a bilateral infusion into the anterior DLS (aDLS) of the dopamine receptor antagonist α-flupentixol. While most rats acquired a polydipsic drinking response with water, others only did so with alcohol. Whether drinking water or alcohol, the acquisition of this coping response was insensitive to aDLS dopamine receptor blockade. In contrast, after prolonged experience, adjunctive drinking became dependent on aDLS dopamine at a time when it was compulsive in vulnerable individuals. These data suggest that habits may develop out of negative reinforcement and that the engagement of their underlying striatal system is necessary for the manifestation of compulsive adjunctive behaviors.

The development of compulsive coping behaviour is associated with a downregulation of Arc in a Locus Coeruleus neuronal ensemble

Some compulsive disorders have been considered to stem from the loss of control over coping strategies, such as displacement. However, the cellular mechanisms involved in the acquisition of coping behaviours and their subsequent compulsive manifestation in vulnerable individuals have not been elucidated. Considering the role of the locus coeruleus (LC) noradrenaline-dependent system in stress and related excessive behaviours, we hypothesised that neuroplastic changes in the LC may be associated with the acquisition of an adjunctive polydipsic water drinking, a prototypical displacement behaviour, and the ensuing development of compulsion in vulnerable individuals. Thus, male Sprague Dawley rats were characterised for their tendency, or not, to develop compulsive polydipsic drinking in a schedule-induced polydipsia (SIP) procedure before their fresh brains were harvested. A new quantification tool for RNAscope assays revealed that the development of compulsive adjunctive behaviour was associated with a low mRNA copy number of the plasticity marker Arc in the LC which appeared to be driven by specific adaptations in an ensemble of tyrosine hydroxylase (TH)+, zif268− neurons. This ensemble was specifically engaged by the expression of compulsive adjunctive behaviour, not by stress, because its functional recruitment was not observed in individuals that no longer had access to the water bottle before sacrifice, while it consistently correlated with the levels of polydipsic water drinking only when it had become compulsive. Together these findings suggest that downregulation of Arc mRNA levels in a population of a TH+/zif268− LC neurons represents a signature of the tendency to develop compulsive coping behaviours.

Is increased operant wheel running on a fixed-ratio schedule due to adjunctive or reinforced behavior?

Do operant wheel running rates that produce the delivery of sucrose on a schedule of reinforcement increase due to adjunctive or reinforced behavior? The current study addressed this question by exposing seven female Long Evans rats in running wheels to a fixed ratio (FR) 40 schedule. Across three conditions, the 40th revolution on this schedule produced the delivery of a drop of 0% (water), 25%, and 0% sucrose solution. Operant wheel-running rates, at a session level, were significantly higher when 25% sucrose was delivered. Median PRPs increased systematically with the consumption of sucrose. Wheel-running rates increased equivalently over all revolutions on the FR 40 for most rats, with only one rat showing an adjunctive pattern of increased running over earlier revolutions. Consequently, it was concluded that the increase in operant wheel-running rates, in the current, as well as prior studies using FR schedules, was due to reinforced rather adjunctive behavior.

The Appalachia Mind Health Initiative (AMHI): a pragmatic randomized clinical trial of adjunctive internet-based cognitive behavior therapy for treating major depressive disorder among primary care patients

BackgroundMajor depressive disorder (MDD) is a leading cause of disease morbidity. Combined treatment with antidepressant medication (ADM) plus psychotherapy yields a much higher MDD remission rate than ADM only. But 77% of US MDD patients are nonetheless treated with ADM only despite strong patient preferences for psychotherapy. This mismatch is due at least in part to a combination of cost considerations and limited availability of psychotherapists, although stigma and reluctance of PCPs to refer patients for psychotherapy are also involved. Internet-based cognitive behaviorial therapy (i-CBT) addresses all of these problems.MethodsEnrolled patients (n = 3360) will be those who are beginning ADM-only treatment of MDD in primary care facilities throughout West Virginia, one of the poorest and most rural states in the country. Participating treatment providers and study staff at West Virginia University School of Medicine (WVU) will recruit patients and, after obtaining informed consent, administer a baseline self-report questionnaire (SRQ) and then randomize patients to 1 of 3 treatment arms with equal allocation: ADM only, ADM + self-guided i-CBT, and ADM + guided i-CBT. Follow-up SRQs will be administered 2, 4, 8, 13, 16, 26, 39, and 52 weeks after randomization. The trial has two primary objectives: to evaluate aggregate comparative treatment effects across the 3 arms and to estimate heterogeneity of treatment effects (HTE). The primary outcome will be episode remission based on a modified version of the patient-centered Remission from Depression Questionnaire (RDQ). The sample was powered to detect predictors of HTE that would increase the proportional remission rate by 20% by optimally assigning individuals as opposed to randomly assigning them into three treatment groups of equal size.Aggregate comparative treatment effects will be estimated using intent-to-treat analysis methods. Cumulative inverse probability weights will be used to deal with loss to follow-up. A wide range of self-report predictors of MDD heterogeneity of treatment effects based on previous studies will be included in the baseline SRQ. A state-of-the-art ensemble machine learning method will be used to estimate HTE.DiscussionThe study is innovative in using a rich baseline assessment and in having a sample large enough to carry out a well-powered analysis of heterogeneity of treatment effects. We anticipate finding that self-guided and guided i-CBT will both improve outcomes compared to ADM only. We also anticipate finding that the comparative advantages of adding i-CBT to ADM will vary significantly across patients. We hope to develop a stable individualized treatment rule that will allow patients and treatment providers to improve aggregate treatment outcomes by deciding collaboratively when ADM treatment should be augmented with i-CBT.Trial registrationClinicalTrials.gov NCT04120285. Registered on October 19, 2019.

Pulpectomy versus Extraction for the Treatment of Nonvital Primary Second Molars: A Retrospective Chart Review.

The current investigation evaluated parameters leading to the utilization of pulpectomy versus extraction for treatment of nonvital primary second molars. This retrospective chart review identified patients up to 8-years of age with primary second molars treated by pulpectomy or extraction. Patients in the extraction group were age and gender-matched to the pulpectomy group. Demographic, clinical, radiographic and behavioral data were extracted for comparison. Chi-square, Fisher and T-test were performed for statistical analysis. There were 23 patients in each group, with a mean age of 5 years (ranging 3-8 years, ±1.5 for pulpectomy and ±1.3 for extraction). Significantly more pulpectomies were performed in the mandible (p=0.002), specifically on the left side (p=0.0035). Internal and external root resorption were significantly higher in the extraction group (p=0.033 and p=0.007 respectively). Restorability was significantly lower in the extraction group (p<0.0001). Pre-procedural pain was reported by 76.5 percent of all patients, but pharmacologically treated in 15.2 percent. Nitrous oxide was administered to 73.9 percent of patients for behavior guidance. Pathologic root resorption and non-restorability were significantly higher in the extraction group. Behavior and pathologic bone resorption did not influence treatment choice. A higher proportion of children reported pre-treatment pain and needed adjunctive behavior guidance than children who did not have pre-treatment pain or did not need adjunctive behavior guidance.

William D. Timberlake (1942-2019).

Presents the obituary of William D. Timberlake (1942-2019). William David Timberlake contributed to psychology in many ways. He is best known for his behavior systems approach to learning and for his disequilibrium theory of reinforcement. He also made important contributions to behavioral economics, circadian rhythms, time horizons, adjunctive behavior, and contrast effects. In these pursuits and others, Timberlake brought clarity to vexing theoretical problems through careful attention to the species-typical characters of the subjects and how these interact with the specifics of apparatus and procedures. He focused on understanding the animals as animals (what he called a theromorphic approach). Timberlake embraced the complexity of behavior, its organization, and its relation to the body as part of a whole, functioning organism (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Translational research: The ontological relation between adjunctive and stereotyped behavior case

Translational research has reported several benefits as a heuristic strategy of knowledge expansion. Given that some authors have found similarities between adjunctive behavior and stereotyped behavior, the present paper analyze if these two kinds of behavior could be raw material for translational research. As elements of the analytical work adjunctive andstereotyped behaviors were described in their relationship with timing and Autism Spectrum Disorder, respectively. Then, a morphological and a functional assessment between both types of behavior were carried out. Main results showed morphological similarities and functional differences between types of behavior which were discussed in terms of suitability for translational research and in terms of the analytical tools utilized.

Wheel running induced by intermittent food schedules

Abstract Sixteen naïve male Wistar rats were exposed to intermittent food delivery to measure the development of schedule-induced wheel running, using fixed time (FT) 30, 60, 120, 240 and 480 s schedules, counterbalanced across animals according to a Latin square design (except under the FT 480 s, which was always presented last to complete the data set). Rats were also exposed to a massed-food control condition. Wheel running was induced in the range of 30-240 s with a gradation as a function of inter-food interval (IFI) length. The temporal distribution of wheel turns was generally presented in the form of an inverted U-shaped as IFIs progressed, showing maximum responding during the first portion of the interval. The introduction of massed-food resulted in an immediate reduction in wheel running. These results support the notion that wheel running can be schedule-induced and categorized into the so-called adjunctive behaviors. These data indicate that IFI length affects the development of schedule-induced wheel running and that the rate of wheel running is maintained by intermittent reinforcement, which are common characteristics of schedule-induced behaviors. Likewise, this idea is supported by the occurrence of a similar temporal pattern to that found with other adjunctive behaviors, such as schedule-induced polydipsia, with its maximum manifestation occurring between the beginning and middle of IFIs.

Activation of trace amine-associated receptor 1 attenuates schedule-induced polydipsia in rats

Trace Amine Associated Receptor 1 (TAAR1) is a novel pharmacological target. TAAR1 are well-documented to play a modulatory role in the dopaminergic system. In spite of a growing number of studies of TAAR1 effects, little is still known about the behavioral pharmacology of TAAR1 ligands, including effects of repeated TAAR1 agonist administration. The present study appears to be the first that estimated the action of TAAR1 agonists on schedule-induced polydipsia, a type of adjunctive behavior, which is considered to be useful for evaluating certain aspects of obsessive-compulsive and related disorders (OCD) and schizophrenia.Our results have demonstrated that the wide range of RO5263397, the highly selective partial TAAR1 agonist, doses (1–10 mg/kg) attenuated the polydipsia induced by two different schedules of food delivery in rats. The effect remained unchanged for the 7 days of repeated treatment. However, the highest tested doses of RO5263397 (6 and 10 mg/kg) decreased the vertical locomotor activity of the animals and the volume of water intake of thirsty rats following the acute treatment. Also, though, the repeated RO5263397 administration is exhibited to diminish the volume of consumed water and weight of rats without SIP, on the other hand, the tolerance was observed to these drug effects.In general, the RO5263397 decreases specifically the adjunctive drinking and this effect is maintained with repeated drug administration without the development of tolerance. The interpretation of these results as an evidence for the RO5263397 anticompulsive-like action, however, should be taken with caution because the drug also influenced the drinking behavior and only weakly affected the other parameters of SIP used to reveal the potential anticompulsive-like effects of drugs.

Can surprising nonreward and adjunctive behavior influence each other?

Can surprising nonreward and adjunctive behavior influence each other?

Selection as a domain-general evolutionary process

The behavioral phenotype of an organism results from selective processes acting on variation in behavioral traits during ontogeny (during life span) and phylogeny (across generations). Different adaptive processes can be categorized as environment-phenotype feedback loops. In this cross-disciplinary approach, we discuss the interaction of ontogenetic selective processes, traditionally studied by behavior analysts, and phylogenetic selection processes, traditionally studied by biologists. We elaborate upon the Extended Evolutionary Synthesis by addressing the connection between selection as a domain-general process and phenomena such as classical and operant conditioning, imprinting, adjunctive behavior, and gene-culture coevolution. Selection is in this context understood as a dynamic iterative feedback loop producing a phenotype beyond the strict morphotype. The extended phenotype is related to the concept of niche construction in which the behavior of organisms shapes their environment, which again selects the behavior of the organisms in an iterative process. A discussion of interacting environmental factors selecting human food choice both during phylogeny and ontogeny exemplifies the generality of selection processes acting on behavior.

Reinforcement of schedule-induced drinking in rats by lick-contingent shortening of food delivery.

Schedule-induced drinking has been a theoretical question of concern ever since it was first described more than 50years ago. It has been classified as adjunctive behavior; that is, behavior that is induced by an incentive but not reinforced by it. Nevertheless, some authors have argued against this view, claiming that adjunctive drinking is actually a type of operant behavior. If this were true, schedule-induced drinking should be controlled by its consequences, which is the major definition of an operant. The present study tested this hypothesis. In a first experimental phase, a single pellet of food was delivered at regular 90-s intervals, but the interfood interval could be shortened depending on the rat's licking. The degree of contingency between licking the bottle spout and hastening the delivery of the food pellet was 100%, 50%, and 0% for 3 separate groups of animals. Rats that could shorten the interval (100% and 50% contingency) drank at a higher rate than those that could not (0%), and the level of acquisition was positively related to the degree of contingency. In a second phase of the experiment, all groups were exposed to a 100% contingency, which resulted in all rats developing high levels of schedule-induced drinking. Licking is enhanced if it hastens reinforcement, and can do so at delay characteristics of those present in studies of schedule-induced drinking, thus supporting the view that adjunctive behavior is an operant.

Schedule-induced polydipsia is associated with increased spine density in dorsolateral striatum neurons

Schedule-induced polydipsia (SIP) is an adjunctive behavior in which rats exhibit excessive drinking as a consequence of intermittent feeding, and it has been proposed as a candidate model to study the development of compulsive and repetitive behavior. Although several brain structures are involved in compulsive behavior, it has been suggested that alterations in fronto-striatal circuits may underlie compulsive spectrum disorders. In the present work, we examined whether SIP would induce modifications in dorsolateral striatum (DLS) and anterior prefrontal cortex (aPFC) neurons. Specifically, the effects of 20 sessions of SIP were determined in the dendrites of DLS medium spiny neurons and in the basal dendritic arbors of layer V pyramidal cells in the aPFC. The structure, size and branching complexity in aPFC neurons were also studied. Results showed that SIP resulted in an increase in dendritic spine density in DLS neurons. Moreover, dendritic spine density was highly correlated with the level of drinking in animals subjected to SIP. By contrast, we observed no differences either in dendritic spine density or in the morphological structure of the dendrites of the aPFC in SIP rats compared to their control counterparts. We hypothesize that SIP-induced structural plasticity in DLS neurons could be related to inflexible response in compulsive behavior. The findings of this study could provide new insights into the involvement of particular cell populations of the dorsolateral striatum and anterior prefrontal cortex regions in compulsive spectrum disorders.

Different relations between schedule-induced polydipsia and impulsive behaviour in the Spontaneously Hypertensive Rat and in high impulsive Wistar rats: Questioning the role of impulsivity in adjunctive behaviour

Rats belonging to three different strains (15 Wistar, 8 Spontaneously Hypertensive – SHR- and 8 Wistar Kyoto – WKY-) were used to evaluate the possible relationship between different levels of impulsivity and development of schedule-induced polydipsia (SIP). We first measured the rats’ levels of impulsivity by means of delay-discounting and indifference-point procedures. Secondly, development of SIP was studied under a series of fixed time 15, 30, 60 and 120s food schedules, which were counterbalanced by means of a Latin-square design. Finally, we re-assessed the rats’ levels of impulsivity by replicating the delay-discounting test. The findings showed that, starting from equivalent levels of impulsivity, development of SIP differed among the groups of rats. In comparison with the rest of the animals, the SHRs were observed to attain elevated drinking rates under SIP. On the other hand, the Wistar rats which had initial high impulsivity levels similar to those of the SHRs, displayed the lowest rates of induced drinking. Moreover, low levels of impulsivity in Wistar rats prior to SIP acquisition were reflected into high drinking rates. Relation of SIP and impulsivity is questioned by present results, which gives ground to the understanding of the behavioural mechanisms involved in adjunctive behaviour and its usefulness as an animal model of excessive behaviour.

Generalized Anxiety Disorder and Depression: A Learning Theory Connection

This paper offers a new learning theory-based conceptualization of worry in Generalized Anxiety Disorder (GAD). The authors suggest that the processes that produce GAD symptoms may vary across GAD sufferers and that treatment effectiveness may be enhanced if the process that likely produced symptoms in a given individual is understood. Specifically, they suggest that a “worry as adjunctive behavior” hypothesis be added to the “worry as anxiety” and “worry as avoidance behavior” hypotheses currently considered. This new hypothesis suggests that for some worriers, worry may function as an adjunctive behavior; that is, a way of accessing quick satisfaction when daily living produces too little response contingent reinforcement. The authors explain that life events that give rise to adjunctive behavior are the same as those that contribute to depression and that this might help explain the high comorbidity between GAD and depression. In cases in which worry appears to serve an adjunctive function, treating GAD symptoms as depression would be treated (e.g., with behavioral activation) may be the most successful course of action.

Combined effects of food deprivation and food frequency on the amount and temporal distribution of schedule‐induced drinking

Under intermittent food schedules animals develop temporally organized behaviors throughout interfood intervals, with behaviors early in the intervals (interim) normally occurring in excess. Schedule-induced drinking (a prototype of interim, adjunctive behavior) is related to food deprivation and food frequency. This study investigated the interactions that resulted from combining different food-deprivation levels (70%, 80% or 90% free-feeding weights) with different food-occurrence frequencies (15-, 30- or 60-s interfood intervals) in a within-subjects design. Increases in food deprivation and food frequency generally led to increased licking, with greater differences due to food deprivation as interfood intervals became shorter. Distributions of licking were modestly shifted to later in the interfood interval as interfood intervals lengthened, a result that was most marked under 90% food deprivation, which also resulted in flatter distributions. It would therefore appear that food deprivation modulates the licking rate and the distribution of licking in different ways. Effects of food deprivation and food frequency are adequately explained by a theory of adjunctive behavior based on delayed food reinforcement, in contrast to alternative hypotheses.

The relationship between adjunctive drinking, blood ethanol concentration and plasma corticosterone across fixed-time intervals of food delivery in two inbred mouse strains

Schedules of intermittent food delivery induce excessive fluid intake, termed schedule-induced polydipsia (SIP), and hypothalamic-pituitary-adrenal (HPA) axis activation is important for the expression and maintenance of this adjunctive behavior. Previous work has focused on examining the relationship between water intake and plasma corticosterone (CORT) in rats at a single or a limited range of fixed time (FT) intervals. However, little remains known regarding SIP and the corresponding stress response (1) across the bitonic function that epitomizes adjunctive behavior, (2) when ethanol is the available fluid, and (3) when a species other than rat or multiple strains are studied. Here we report the findings from ethanol-preferring C57BL/6J (B6) and non-preferring DBA/2J (D2) mice serially exposed to progressively larger FT intervals (0 → 60 min) and given access to either water or a 5% (v/v) ethanol solution. Following 2 weeks of experience with each schedule, blood samples were collected at the conclusion of the last 60-min session to evaluate CORT and the blood ethanol concentration (BEC) achieved. While both strains exhibited a bitonic function of ethanol intake and BEC that peaked at or near a 5-min interval, only D2 mice showed a similar response with water. In contrast, CORT levels rose monotonically with incremental increases in the FT interval regardless of the strain examined or fluid type offered, indicating that glucocorticoid release likely reflects the aversive aspects of increasing intervals between reinforcement rather than engagement in adjunctive behavior. These findings also caution against the use of a single intensity stressor to evaluate the relationship between stress and ethanol intake, as the magnitude of stress appears to affect ethanol consumption in a non-linear fashion.