Treating depression in patients with borderline personality disorder: clinical clues on the use of antidepressants.

Personality disorders (PD) are described as enduring patterns of markedly deviant and pervasive inner experiences and behaviors, with onset in adolescence, which lead to severe distress or impairment. Patients suffering from major depressive disorder (MDD) display higher rates of comorbidity with personality disorders, often complicating the treatment, and worsening the outcomes. Borderline personality disorder (BPD) is the most common of PD and is frequently associated with MDD, with which shares several features. The most part of research agrees on the fact that comorbid BPD in MDD patients quite doubles the poor response to treatments. Moreover, no treatment strategy stands out currently to emerge as more effective in these cases, thus urging the call for the need of new approaches. Herein, we revise the current literature on BPD, its neurobiology and comorbidity with MDD, as well as the more recent treatment strategies used. Then, based on its pharmacology, we propose a possible role of trazodone as a valuable tool to approach comorbid BPD-MDD.

Treating depression in clinical practice: new insights on the multidisciplinary use of trazodone.

Depression is estimated to be a leading contributor to the global mental health-related burden. The determinants of this huge prevalence lie in the fact that depressive symptoms may be comorbid in a wide variety of disorders, thus complicating and exacerbating their clinical framework. This makes the treatment of depressive symptoms difficult, since many pharmacological interactions should be considered by physicians planning therapy. Hence, depression still represents a challenge for both psychiatrists and other clinicians, in terms of its high rates of relapse and resistance despite well-established protocols. It is also complicated by the well-known latency in its complete response to current antidepressant treatments. In this context, the search for new strategies regarding antidepressant treatment is mandatory. Revising the use of "old" pharmacotherapies by considering their specific features may help to perfecting the treatment of depression, both in its standalone psychiatric manifestation and in the framework of other clinical conditions. Using a nominal group technique approach, the results of a consensus of expert physicians regarding the possible use of trazodone as a valuable strategy for addressing the "real world" unmet needs of depression treatment in different fields (psychiatry, primary care, neurology and geriatrics) is herein provided. This idea is based on the unique characteristics of this drug which delivers a more rapid antidepressant action as compared to other selective serotonin reuptake inhibitors. It also has pharmacodynamic malleability (i.e., the possibility of exerting different effects on depressive symptoms at different dosages) and pharmacokinetic tolerability (i.e., the possibility of being used as an add-on to other antidepressants with scarce interaction and achieving complimentary effects) when used in the milieu of other drugs in treating comorbid depressive symptoms. Moreover, the large number of formulations available permits finite dosage adjustments, and the use of trazodone for specific pathologies, such as dysphagia. Therefore, although additional studies exploring the real-world conditions of antidepressant treatment are warranted, experts agree on the idea that depressive disorder, in both its standalone and its comorbid manifestations, may surely take advantage of the particular characteristics of trazodone, thus attempting to reach the greatest effectiveness in different contexts.

A Postsynaptic Density Immediate Early Gene-Based Connectome Analysis of Acute NMDAR Blockade and Reversal Effect of Antipsychotic Administration.

Although antipsychotics' mechanisms of action have been thoroughly investigated, they have not been fully elucidated at the network level. We tested the hypothesis that acute pre-treatment with ketamine (KET) and administration of asenapine (ASE) would modulate the functional connectivity of brain areas relevant to the pathophysiology of schizophrenia, based on transcript levels of Homer1a, an immediate early gene encoding a key molecule of the dendritic spine. Sprague-Dawley rats (n = 20) were assigned to KET (30 mg/kg) or vehicle (VEH). Each pre-treatment group (n = 10) was randomly split into two arms, receiving ASE (0.3 mg/kg), or VEH. Homer1a mRNA levels were evaluated by in situ hybridization in 33 regions of interest (ROIs). We computed all possible pairwise Pearson correlations and generated a network for each treatment group. Acute KET challenge was associated with negative correlations between the medial portion of cingulate cortex/indusium griseum and other ROIs, not detectable in other treatment groups. KET/ASE group showed significantly higher inter-correlations between medial cingulate cortex/indusium griseum and lateral putamen, the upper lip of the primary somatosensory cortex, septal area nuclei, and claustrum, in comparison to the KET/VEH network. ASE exposure was associated with changes in subcortical-cortical connectivity and an increase in centrality measures of the cingulate cortex and lateral septal nuclei. In conclusion, ASE was found to finely regulate brain connectivity by modelling the synaptic architecture and restoring a functional pattern of interregional co-activation.

The Homer1 family of proteins at the crossroad of dopamine-glutamate signaling: An emerging molecular "Lego" in the pathophysiology of psychiatric disorders. A systematic review and translational insight.

Once considered only scaffolding proteins at glutamatergic postsynaptic density (PSD), Homer1 proteins are increasingly emerging as multimodal adaptors that integrate different signal transduction pathways within PSD, involved in motor and cognitive functions, with putative implications in psychiatric disorders. Regulation of type I metabotropic glutamate receptor trafficking, modulation of calcium signaling, tuning of long-term potentiation, organization of dendritic spines' growth, as well as meta- and homeostatic plasticity control are only a few of the multiple endocellular and synaptic functions that have been linked to Homer1. Findings from preclinical studies, as well as genetic studies conducted in humans, suggest that both constitutive (Homer1b/c) and inducible (Homer1a) isoforms of Homer1 play a role in the neurobiology of several psychiatric disorders, including psychosis, mood disorders, neurodevelopmental disorders, and addiction. On this background, Homer1 has been proposed as a putative novel target in psychopharmacological treatments. The aim of this review is to summarize and systematize the growing body of evidence on Homer proteins, highlighting the role of Homer1 in the pathophysiology and therapy of mental diseases.

Gut Microbiota and Bipolar Disorder: An Overview on a Novel Biomarker for Diagnosis and Treatment.

The gut microbiota is the set of microorganisms that colonize the gastrointestinal tract of living creatures, establishing a bidirectional symbiotic relationship that is essential for maintaining homeostasis, for their growth and digestive processes. Growing evidence supports its involvement in the intercommunication system between the gut and the brain, so that it is called the gut-brain-microbiota axis. It is involved in the regulation of the functions of the Central Nervous System (CNS), behavior, mood and anxiety and, therefore, its implication in the pathogenesis of neuropsychiatric disorders. In this paper, we focused on the possible correlations between the gut microbiota and Bipolar Disorder (BD), in order to determine its role in the pathogenesis and in the clinical management of BD. Current literature supports a possible relationship between the compositional alterations of the intestinal microbiota and BD. Moreover, due to its impact on psychopharmacological treatment absorption, by acting on the composition of the microbiota beneficial effects can be obtained on BD symptoms. Finally, we discussed the potential of correcting gut microbiota alteration as a novel augmentation strategy in BD. Future studies are necessary to better clarify the relevance of gut microbiota alterations as state and disease biomarkers of BD.

Modulation of glutamatergic functional connectivity by a prototypical antipsychotic: Translational inference from a postsynaptic density immediate-early gene-based network analysis.

BACKGROUND: Although extensively studied, the effect of antipsychotics is not completely understood at a network level. We tested the hypothesis that acute administration of haloperidol would modulate functional connectivity of brain regions relevant to schizophrenia pathophysiology. To assess putative changes in brain network properties and regional interactivity, we studied the expression of Homer1a, an Immediate Early Gene (IEG) demonstrated to be induced by antipsychotic administration and coding for a protein involved in glutamatergic synapses remodeling. METHODS: Sprague-Dawley rats (n = 26) assigned to vehicle (VEH; NaCl 0.9%) or haloperidol (HAL; 0.8 mg/kg) were included in the network analysis. Homer1a mRNA induction was evaluated by in situ hybridization. Signal intensity analysis was performed in 33 Regions of Interest (ROIs) in the cortex, the caudate putamen, and the nucleus accumbens. A signal correlation analysis was performed, computing all possible pairwise Pearson correlations among ROIs in the two groups. Two networks were generated for HAL and VEH groups, and their properties and topography were explored. RESULTS: VEH and HAL networks showed qualitative differences in global efficiency and clustering coefficient. The HAL network showed enhanced interactivity between cortical and striatal regions, and within caudate putamen subdivisions. On the other hand, it exhibited reduced inter-correlations between cingulate cortex and anterior insula and caudate putamen and nucleus accumbens. Moreover, haloperidol was able to modulate centrality of crucial functional hubs. These preclinical results corroborate and expand the clinical evidence that antipsychotics may modulate specific brain network properties and disease-related circuits' interactivity.

The 'dead man walking' disorder: an update on Cotard's syndrome.

In 1880, Jules Cotard described a peculiar syndrome after observing the case of a 43-year-old woman, which was characterized by melancholic anxiety, delusions of damnation or possession, a higher propensity to suicide ideation and deliberate self-harm, analgesia, hypochondriac thoughts of non-existence or ruin of several organs, of the whole body, of the soul, of divinity, and the idea of immortality or inability to die. Several expansions and reinterpretations have been made of the so-called Cotard's syndrome, which is often encompassed in different neurological and psychiatric disorders, complicating and worsening their symptomatic frameworks and making more difficult their treatments. However, the nosographic characterization of Cotard's syndrome remains elusive and is not now classified as a separate disorder in both ICD and DSM-5. Here, we try to give an update, as well as a putative systematization, of current views and opinions about this nosological entity in the light of the recent progress in the clinic, psychopathology and psycho-neurobiology.

Adjunctive vortioxetine for SSRI-resistant major depressive disorder: a real-world chart review study

Objective: Selective serotonin reuptake inhibitors (SSRIs) are the cornerstone of treatment of major depressive disorder (MDD). However, non-response is common, often necessitating combination strategies. The present study assessed the efficacy of vortioxetine as an add-on therapy in patients with SSRI-resistant MDD. Methods: The charts of 36 adult outpatients with DSM-IV-TR MDD who had not achieved a response after at least 8 weeks of treatment with an SSRI were reviewed retrospectively. Subjects were treated with vortioxetine (5-20 mg/day) for 8 weeks added to the current SSRI. The main outcome measures were change from baseline in total Hamilton Scale for Depression (HAM-D) score and the rate of response (a 50% or greater reduction in HAM-D score and a Clinical Global Impression ‐ Improvement module [CGI-I] score of 1 or 2 at endpoint). HAM-D scores ≤ 7 were considered as remission. Additional outcome measures included the Snaith-Hamilton Pleasure Scale (SHAPS) and the Scale for Suicide Ideation (SSI). Results: 32 patients completed the 8 weeks of treatment. At 8 weeks, a significant reduction in HAM-D score was observed (p ≤ 0.001), with response obtained by 41.7% and remission by 33.3% of patients. Significant reductions in SHAPS and SSI were also observed (p ≤ 0.001 for both scales). Conclusions: Adjunctive vortioxetine may be useful and well-tolerated in stage I treatment-resistant depression. However, the limitations of this study (such as small sample size, absence of randomization and control group, retrospective design, etc.) must be considered.

Understanding the Complex of Suicide in Depression: from Research to Clinics.

OBJECTIVE: Amongst psychiatric disorders, major depressive disorder (MDD) is the most prevalent, by affecting approximately 15-17% of the population and showing a high suicide risk rate equivalent to around 15%. The present comprehensive overview aims at evaluating main research studies in the field of MDD at suicide risk, by proposing as well as a schematic suicide risk stratification and useful flow-chart for planning suicide preventive and therapeutic interventions for clinicians. METHODS: A broad and comprehensive overview has been here conducted by using PubMed/Medline, combining the search strategy of free text terms and exploded MESH headings for the topics of 'Major Depressive Disorder' and 'Suicide' as following: ((suicide [Title/Abstract]) AND (major depressive disorder [Title/Abstract])). All articles published in English through May 31, 2019 were summarized in a comprehensive way. RESULTS: Despite possible pathophysiological factors which may explain the complexity of suicide in MDD, scientific evidence supposed the synergic role of genetics, exogenous and endogenous stressors (i.e., interpersonal, professional, financial, as well as psychiatric disorders), epigenetic, the hypothalamic-pituitary-adrenal stress-response system, the involvement of the monoaminergic neurotransmitter systems, particularly the serotonergic ones, the lipid profile, neuro-immunological biomarkers, the Brain-derived neurotrophic factor and other neuromodulators. CONCLUSION: The present overview reported that suicide is a highly complex and multifaceted phenomenon in which a large plethora of mechanisms could be variable implicated, particularly amongst MDD subjects. Beyond these consideration, modern psychiatry needs a better interpretation of suicide risk with a more careful assessment of suicide risk stratification and planning of clinical and treatment interventions.

Adjunctive vortioxetine for SSRI-resistant major depressive disorder: a "real-world" chart review study.

OBJECTIVE: Selective serotonin reuptake inhibitors (SSRIs) are the cornerstone of treatment of major depressive disorder (MDD). However, non-response is common, often necessitating combination strategies. The present study assessed the efficacy of vortioxetine as an add-on therapy in patients with SSRI-resistant MDD. METHODS: The charts of 36 adult outpatients with DSM-IV-TR MDD who had not achieved a response after at least 8 weeks of treatment with an SSRI were reviewed retrospectively. Subjects were treated with vortioxetine (5-20 mg/day) for 8 weeks added to the current SSRI. The main outcome measures were change from baseline in total Hamilton Scale for Depression (HAM-D) score and the rate of response (a 50% or greater reduction in HAM-D score and a Clinical Global Impression - Improvement module [CGI-I] score of 1 or 2 at endpoint). HAM-D scores ≤ 7 were considered as remission. Additional outcome measures included the Snaith-Hamilton Pleasure Scale (SHAPS) and the Scale for Suicide Ideation (SSI). RESULTS: 32 patients completed the 8 weeks of treatment. At 8 weeks, a significant reduction in HAM-D score was observed (p ≤ 0.001), with response obtained by 41.7% and remission by 33.3% of patients. Significant reductions in SHAPS and SSI were also observed (p ≤ 0.001 for both scales). CONCLUSIONS: Adjunctive vortioxetine may be useful and well-tolerated in stage I treatment-resistant depression. However, the limitations of this study (such as small sample size, absence of randomization and control group, retrospective design, etc.) must be considered.

How does ayahuasca work from a psychiatric perspective? Pros and cons of the entheogenic therapy.

OBJECTIVE: Ayahuasca is a hallucinogenic plant preparation, traditionally consumed in sacred ceremonies by indigenous North-Westerner Amazonian countries like Colombia, Peru, Brazil, and Ecuador. It is fundamental to carefully balance benefits/risks related to the ayahuasca intake, both during ceremonies and experimental settings. The aim is at evaluating and comparing the potential therapeutic benefits versus health risks related to ayahuasca intake (both acutely and chronically), focusing on its application in psychedelic psychiatry. DESIGN: A comprehensive mini overview focusing on psychiatric outcomes following ayahuasca intake both in healthy volunteers and in clinical samples. RESULTS: Preclinical, observational, and experimental studies in healthy volunteers as well as in clinical samples suggest that ayahuasca may be beneficial as an antidepressant, emotional regulator, anxiolytic, and antiaddictive drug, by exerting fast-acting and enduring clinical effects. Ayahuasca appears to be safe and well tolerated, nausea and emesis being the most reported and transient side effects. Some findings suggest not to use ayahuasca in bipolar or psychotic patients because of an increased risk of manic switch and/or psychotic onset. CONCLUSIONS: Further research should be carried out in randomized, double-blind, placebo-controlled trials, by implementing neuroimaging studies, in order to better evaluate therapeutic potential of ayahuasca in mental disorders.

An Update on Glutamatergic System in Suicidal Depression and on the Role of Esketamine.

BACKGROUND: A research on mood disorder pathophysiology has hypothesized abnormalities in glutamatergic neurotransmission, by suggesting further investigation on glutamatergic N-methyl-Daspartate (NMDA) receptor modulators in treating Major Depressive Disorder (MDD). Esketamine (ESK), an NMDA receptor antagonist able to modulate glutamatergic neurotransmission has been recently developed as an intranasal formulation for treatment-resistant depression (TRD) and for rapid reduction of depressive symptomatology, including suicidal ideation in MDD patients at imminent risk for suicide. OBJECTIVE: The present study aims at investigating recent clinical findings on research on the role of the glutamatergic system and ESK in treating suicidal depression in MDD and TRD. METHODS: A systematic review was here carried out on PubMed/Medline, Scopus and the database on U.S. N.I.H. Clinical Trials (https://clinicaltrials.gov) and the European Medical Agency (EMA) (https://clinicaltrialsregister.eu) from inception until October 2019. RESULTS: Intravenous infusion of ESK is reported to elicit rapid-acting and sustained antidepressant activity in refractory patients with MDD and TRD. In phase II studies, intranasal ESK demonstrated a rapid onset and a persistent efficacy in patients with TRD as well as in MDD patients at imminent risk for suicide. However, some data discrepancies have emerged in phase III studies. CONCLUSION: The U.S. Food and Drug Administration (FDA) granted fast track and Breakthrough Therapy Designation to Janssen Pharmaceuticals®, Inc. for intranasal ESK in 2013 for treatment-resistant depression (TRD) and in 2016 for the treatment of MDD with an imminent risk of suicide. However, further studies should be implemented to investigate the long-term efficacy and safety of intranasal ESK.

Alexithymia, resilience, somatic sensations and their relationships with suicide ideation in drug naïve patients with first-episode major depression: An exploratory study in the "real world" everyday clinical practice.

AIM: The present study is aimed at revaluating alexithymia, somatic sensations, resilience and their relationships with suicide ideation in drug naïve adult outpatients suffering from first episode major depression (MD). METHODS: Data of 103 adult outpatients (49 men, 56 women) with a diagnostic and statistical manual of mental disorders, 4th edition, text revision (DSM-IV-TR) diagnosis of MD were analysed. Alexithymia was measured using the 20-item Toronto Alexithymia Scale (TAS-20) and resilience with the 25 items Connor-Davidson Resilience Scale (CD-RISC) whereas depression was evaluated using the 17-item Hamilton Depression Rating Scale, somatic sensations with the Body Sensations Questionnaire and suicide ideation with Scale of Suicide Ideation (SSI). RESULTS: Gender comparisons between all demographic and clinical variables showed no significant differences in all variables. Subjects who were found positive for alexithymia showed higher scores on all clinical variables controlling for age, gender and duration of the current episode. In a linear regression model, lower scores on CD-RISC and Difficulty in Identifying Feelings dimension of TAS-20 were significantly predictive of higher scores on SSI. CONCLUSIONS: Alexithymia and low resilience were significant predictors of increased suicide ideation in a first MD episode. However, study limitations must be considered and future research needs are being discussed.

Alexithymia, suicide ideation, affective temperaments and homocysteine levels in drug naïve patients with post-traumatic stress disorder: an exploratory study in the everyday 'real world' clinical practice.

Objective: The present exploratory study aimed to investigate relationships between alexithymia, suicide ideation, affective temperaments and homocysteine levels among drug-naïve adult outpatients with Post-Traumatic Stress Disorder (PTSD) in an everyday 'real world' clinical setting.Method: Sixty-four adult outpatients with PTSD were evaluated using the Davidson Trauma Scale (DTS), the Toronto Alexithymia Scale (TAS-20), the Scale of Suicide Ideation (SSI), the Temperament Evaluation of the Memphis, Pisa, Paris and San Diego-Autoquestionnaire. As well, homocysteine levels were measured.Results: Alexithymic subjects showed higher values on all scales but not homocysteine levels. Partial correlations showed that almost all studied variables were correlated with each other, except homocysteine levels. Regression analysis showed that higher disorder severity as measured by DTS and TAS-20 'Difficulty in Identifying Feelings' dimension was associated with higher SSI scores.Conclusions: In conclusion, alexithymic PTSD outpatients may be characterised by higher disorder severity and difficulty in identifying feelings that may be linked to increased suicide ideation, regardless of affective temperaments or homocysteine levels. Homocysteine levels were not related to any studied variable. However, study limitations are discussed and must be considered. KeypointsPatients with alexithymia showed increased PTSD severity, a higher score on TEMPS-A subscales, and more severe suicide ideation.The Difficulty in Identifying Feelings (DIF) dimension of TAS-20 was associated with suicide ideation in patients with PTSD.Homocysteine did not correlate with any studied variables.This study was exploratory and cross-sectional: further larger and prospective studies are needed.

Novel Pathways in the Treatment of Major Depression: Focus on the Glutamatergic System.

Depressive disorders represent protean psychiatric illnesses with heterogeneous clinical manifestations and a multitude of comorbidities leading to severe disability. In spite of decades of research on the pathophysiogenesis of these disorders, the wide variety of pharmacotherapies currently used to treat them is based on the modulation of monoamines, whose alteration has been considered the neurobiological foundation of depression, and consequently of its treatment. However, approximately one third to a half of patients respond partially or become refractory to monoamine-based therapies, thereby jeopardizing the therapeutic effectiveness in the real world of clinical practice. Recent scientific evidence has been pointing out the essential role of other biological systems beyond monoamines in the pathophysiology of depressive disorders, in particular, the glutamatergic neurotransmission. In the present review, we will discuss the most advanced knowledge on the involvement of glutamatergic system in the molecular mechanisms at the basis of depression pathophysiology, as well as the glutamate-based therapeutic strategies currently suggested to optimize depression treatment (e.g., ketamine). Finally, we will mention further "neurobiological targeted" approaches, based on glutamate system, with the purpose of promoting new avenues of investigation aiming at developing interventions that overstep the monoaminergic boundaries to improve depressive disorders therapy.

Eradicating Suicide at Its Roots: Preclinical Bases and Clinical Evidence of the Efficacy of Ketamine in the Treatment of Suicidal Behaviors.

Despite the continuous advancement in neurosciences as well as in the knowledge of human behaviors pathophysiology, currently suicide represents a puzzling challenge. The World Health Organization (WHO) has established that one million people die by suicide every year, with the impressive daily rate of a suicide every 40 s. The weightiest concern about suicidal behavior is how difficult it is for healthcare professionals to predict. However, recent evidence in genomic studies has pointed out the essential role that genetics could play in influencing person's suicide risk. Combining genomic and clinical risk assessment approaches, some studies have identified a number of biomarkers for suicidal ideation, which are involved in neural connectivity, neural activity, mood, as well as in immune and inflammatory response, such as the mammalian target of rapamycin (mTOR) signaling. This interesting discovery provides the neurobiological bases for the use of drugs that impact these specific signaling pathways in the treatment of suicidality, such as ketamine. Ketamine, an N-methyl-d-aspartate glutamate (NMDA) antagonist agent, has recently hit the headlines because of its rapid antidepressant and concurrent anti-suicidal action. Here we review the preclinical and clinical evidence that lay the foundations of the efficacy of ketamine in the treatment of suicidal ideation in mood disorders, thereby also approaching the essential question of the understanding of neurobiological processes of suicide and the potential therapeutics.

Safety of antipsychotics for the treatment of schizophrenia: a focus on the adverse effects of clozapine.

Clozapine, a dibenzodiazepine developed in 1961, is a multireceptorial atypical antipsychotic approved for the treatment of resistant schizophrenia. Since its introduction, it has remained the drug of choice in treatment-resistant schizophrenia, despite a wide range of adverse effects, as it is a very effective drug in everyday clinical practice. However, clozapine is not considered as a top-of-the-line treatment because it may often be difficult for some patients to tolerate as some adverse effects can be particularly bothersome (i.e. sedation, weight gain, sialorrhea etc.) and it has some other potentially dangerous and life-threatening side effects (i.e. myocarditis, seizures, agranulocytosis or granulocytopenia, gastrointestinal hypomotility etc.). As poor treatment adherence in patients with resistant schizophrenia may increase the risk of a psychotic relapse, which may further lead to impaired social and cognitive functioning, psychiatric hospitalizations and increased treatment costs, clozapine adverse effects are a common reason for discontinuing this medication. Therefore, every effort should be made to monitor and minimize these adverse effects in order to improve their early detection and management. The aim of this paper is to briefly summarize and provide an update on major clozapine adverse effects, especially focusing on those that are severe and potentially life threatening, even if most of the latter are relatively uncommon.

Nicotine and caffeine modulate haloperidol-induced changes in postsynaptic density transcripts expression: Translational insights in psychosis therapy and treatment resistance.

Caffeine and nicotine are widely used by schizophrenia patients and may worsen psychosis and affect antipsychotic therapies. However, they have also been accounted as augmentation strategies in treatment-resistant schizophrenia. Despite both substances are known to modulate dopamine and glutamate transmission, little is known about the molecular changes induced by these compounds in association to antipsychotics, mostly at the level of the postsynaptic density (PSD), a site of dopamine-glutamate interplay. Here we investigated whether caffeine and nicotine, alone or combined with haloperidol, elicited significant changes in the levels of both transcripts and proteins of the PSD members Homer1 and Arc, which have been implicated in synaptic plasticity, schizophrenia pathophysiology, and antipsychotics molecular action. Homer1a mRNA expression was significantly reduced by caffeine and nicotine, alone or combined with haloperidol, compared to haloperidol. Haloperidol induced significantly higher Arc mRNA levels than both caffeine and caffeine plus haloperidol in the striatum. Arc mRNA expression was significantly higher by nicotine plus haloperidol vs. haloperidol in the cortex, while in striatum gene expression by nicotine was significantly lower than that by both haloperidol and nicotine plus haloperidol. Both Homer1a and Arc protein levels were significantly increased by caffeine, nicotine, and nicotine plus haloperidol. Homer1b mRNA expression was significantly increased by nicotine and nicotine plus haloperidol, while protein levels were unaffected. Locomotor activity was not significantly affected by caffeine, while it was reduced by nicotine. These data indicate that both caffeine and nicotine trigger relevant molecular changes in PSD sites when given in association with haloperidol.