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Dive into the research topics where Theodore Kolivakis is active.

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Featured researches published by Theodore Kolivakis.


The Canadian Journal of Psychiatry | 2005

Tardive Dyskinesia in the Era of Typical and Atypical Antipsychotics. Part 2: Incidence and Management Strategies in Patients with Schizophrenia:

Howard C. Margolese; Guy Chouinard; Theodore Kolivakis; Linda Beauclair; Robert Miller; Lawrence Annable

Objective: Tardive dyskinesia (TD), the principal adverse effect of long-term conventional antipsychotic treatment, can be debilitating and, in many cases, persistent. We sought to explore the incidence and management of TD in the era of atypical antipsychotics because it remains an important iatrogenic adverse effect. Methods: We conducted a review of TD incidence and management literature from January 1, 1965, to January 31, 2004, using the terms tardive dyskinesia, management, therapy, neuroleptics, antipsychotics, clozapine, olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole. Additional articles were obtained by searching the bibliographies of relevant references. We considered articles that contributed to the current understanding of both the incidence of TD with atypical antipsychotics and management strategies for TD. Results: The incidence of TD is significantly lower with atypical, compared with typical, antipsychotics, but cases of de novo TD have been identified. Evidence suggests that atypical antipsychotic therapy ameliorates long-standing TD. This paper outlines management strategies for TD in patients with schizophrenia. Conclusion: The literature supports the recommendation that atypical antipsychotics should be the first antipsychotics used in patients who have experienced TD as a result of treatment with conventional antipsychotic agents. The other management strategies discussed may prove useful in certain patients.


The Canadian Journal of Psychiatry | 2005

Tardive Dyskinesia in the Era of Typical and Atypical Antipsychotics. Part 1: Pathophysiology and Mechanisms of Induction

Howard C. Margolese; Guy Chouinard; Theodore Kolivakis; Linda Beauclair; Robert Miller

Objective: Tardive dyskinesia (TD) is the principal adverse effect of long-term treatment with conventional antipsychotic agents. Several mechanisms may exist for this phenomenon. Mechanisms for the lower incidence of TD with atypical antipsychotics also remain to be fully understood. We undertook to explore and better understand these mechanisms. Methods: We conducted a comprehensive review of TD pathophysiology literature from January 1, 1965, to January 31, 2004, using the terms tardive dyskinesia, neuroleptics, antipsychotics, pathophysiology, and mechanisms. Additional articles were obtained by searching the bibliographies of relevant references. Articles were considered if they contributed to the current understanding of the pathophysiology of TD. Results: Current TD vulnerability models include genetic vulnerability, disease-related vulnerability, and decreased functional reserve. Mechanisms of TD induction include prolonged blockade of postsynaptic dopamine receptors, postsynaptic dopamine hypersensitivity, damage to striatal GABA interneurons, and damage of striatal cholinergic interneurons. Atypical antipsychotics may cause less TD because they have less impact on the basal ganglia and are less likely to cause postsynaptic dopamine hypersensitivity. Conclusion: Although the ultimate model for TD is not yet understood, it is plausible that several of these vulnerabilities and mechanisms act together to produce TD. The lower incidence of TD with atypical antipsychotics has helped to elucidate the mechanisms of TD.


Behavioral Neuroscience | 2005

Cocaine craving, euphoria, and self-administration: a preliminary study of the effect of catecholamine precursor depletion.

Marco Leyton; Kevin F. Casey; J. Scott Delaney; Theodore Kolivakis; Chawki Benkelfat

The authors used the acute phenylalanine-tyrosine depletion (APTD) method to test the effect of transient catecholamine precursor depletion on cocaine craving, euphoria, and self-administration. Eight nondependent, nontreatment-seeking cocaine users self-administered 3 doses of cocaine (0.6, 1.5, 3.0 mg/kg, taken intranasally) following ingestion of (a) a nutritionally balanced amino acid mixture, (b) APTD, and (c) APTD followed by L-dopa/carbidopa (2x100 mg/25 mg). APTD decreased both cue and cocaine-induced drug craving but not euphoria or self-administration. APTD+L-dopa also decreased drug craving, possibly reflecting the ability of L-dopa to transiently decrease dopamine cell firing. Together, these preliminary results suggest that the craving elicited by cocaine and cocaine cues is related to changes in catecholamine neurotransmission. Euphoria and the self-administration of freely available drugs by regular users, in comparison, might be better accounted for by other mechanisms.


Biological Psychiatry | 2009

Striatal dopamine responses to intranasal cocaine self-administration in humans.

Sylvia M.L. Cox; Chawki Benkelfat; Alain Dagher; J. Scott Delaney; Samuel A. McKenzie; Theodore Kolivakis; Kevin F. Casey; Marco Leyton

BACKGROUND The effect of self-administered cocaine on extracellular dopamine (DA) levels has not been measured in humans. METHODS Ten nondependent cocaine users underwent positron emission tomography [11C]raclopride scans following intranasal self-administration of cocaine hydrochloride (1.0 mg/kg) and placebo powder. RESULTS Compared with placebo, intranasal cocaine self-administration decreased [11C]raclopride binding values in the ventral limbic striatum and putamen. Individual differences in the magnitude of the [11C]raclopride response in the ventral striatum were predicted by lifetime histories of stimulant drug use. CONCLUSIONS The results suggest that 1) intranasal cocaine self-administration increases synaptic DA levels in human striatum and 2) prior use of stimulant drugs on the street is associated with progressively greater cocaine-induced DA responses. These dopaminergic effects might influence susceptibility to drug-seeking behavior and the progression to substance abuse.


British Journal of Psychiatry | 2011

Effects of lowered serotonin transmission on cocaine-induced striatal dopamine response: PET [11C]raclopride study in humans

Sylvia M.L. Cox; Chawki Benkelfat; Alain Dagher; J. Scott Delaney; Theodore Kolivakis; Kevin F. Casey; Marco Leyton

BACKGROUND Low serotonin transmission is thought to increase susceptibility to a wide range of substance use disorders and impulsive traits. AIMS To investigate the effects of lowered serotonin on cocaine-induced (1.0 mg/kg cocaine, self-administered intranasally) dopamine responses and drug craving. METHOD In non-dependent cocaine users, serotonin transmission was reduced using the acute tryptophan depletion method. Striatal dopamine responses were measured using positron emission tomography with [(11)C]raclopride. RESULTS Acute tryptophan depletion increased drug craving and striatal dopamine responses to cocaine. These acute tryptophan depletion-induced increases did not occur in the absence of cocaine. CONCLUSIONS The results suggest that low serotonin transmission can increase dopaminergic and appetitive responses to cocaine. These findings might identify a mechanism by which individuals with low serotonin are at elevated risk for both substance use disorders and comorbid conditions.


The Canadian Journal of Psychiatry | 2004

Long-term lamotrigine adjunctive to antipsychotic monotherapy in schizophrenia: further evidence.

Theodore Kolivakis; Linda Beauclair; Howard C. Margolese; Guy Chouinard

Endicott J, Maser JD, and others. A prospective investigation of the natural history of the long-term weekly symptomatic status of bipolar II disorder. Arch Gen Psychiatry 2003;60:261–9. 12. First MB, Spitzer RL, Gibbon M, Williams JBW. Structured Clinical Interview for DSM-IV Axis I Disorders–Clinician Version (SCID-CV). Washington (DC): American Psychiatric Press; 1997. 13. Benazzi F, Akiskal HS. Refining the evaluation of bipolar II: beyond the strict SCID-CV guidelines for hypomania. J Affect Disord 2003;73:33–8. 14. Benazzi F. Borderline personality disorder and bipolar II disorder in private practice depressed outpatients. Compr Psychiatry 2000;41:106–10. 15. Weissman MM, Wickramaratne P, Adams P, Wolk S, Verdeli H, Olfson M. Brief screening for family psychiatric history. The family history screen. Arch Gen Psychiatry 2000;57:675–82.


Scientific Reports | 2017

Cocaine Cue-Induced Dopamine Release in Recreational Cocaine Users

Sylvia M.L. Cox; Yvonne Yau; Kevin Larcher; Theodore Kolivakis; J. Scott Delaney; Alain Dagher; Chawki Benkelfat; Marco Leyton

It has been proposed that the acquisition of drug seeking is related to the development of conditioned dopamine responses in the ventral striatum. As drug use continues and becomes habit-like, conditioned responses have been shown to shift to the dorsal striatum. Here, using the PET [11C]raclopride method and highly personalized cocaine cues, we report the first evidence in humans of the dorsal dopamine response prior to the onset of addiction.


The Canadian Journal of Psychiatry | 1983

Stability of Intellect and Personality in Schizophrenia

Dudek Sz; Theodore Kolivakis

A group of 52 chronic schizophrenic patients (mean age 41) currently maintained on follow-up treatment at an outpatient clinic were re-evaluated 8.5 years after initial treatment at the Allan Memorial Institute. The instruments used were the Spitzer Mental Status Schedule (MSS), the verbal WAIS, Rorschach and several thinking disorder tests. A verbal IQ finding of 1.4 points of increase (n.s.) indicates that no intellectual deterioration has occurred as measured by the WAIS. The thinking disorder tests, however, reveal considerable deficit. The Rorschach shows no evidence of personality change although there is evidence of increasing personality impoverishment, as evident in a progressive flattening of affect, and an increasing withdrawal and isolation. These inferences are supported by case history data and by the MSS psychiatric rating scale.


International Clinical Psychopharmacology | 2018

Antidepressant combination versus antidepressants plus second-generation antipsychotic augmentation in treatment-resistant unipolar depression

Gabriella Gobbi; Maykel F. Ghabrash; Nicolas Nuñez; John Tabaka; Jessica Di Sante; Marie Saint-Laurent; Stephen Vida; Theodore Kolivakis; Nancy Low; Pablo Cervantes; Linda Booij; Stefano Comai

Patients with treatment-resistant unipolar depression (TRD) are treated with antidepressant combinations (ADs) or with second-generation antipsychotics plus AD (SGA+AD) augmentation; however, the clinical characteristics, the factors associated independently with response to SGA+AD, and the outcome trajectories have not yet been characterized. We performed a naturalistic study on the latest stable trial (medication unchanged for about 3 months) in 86 TRD patients with resistance to at least two ADs trials, who received ADs (n=36) or SGA+AD (n=50) treatments. Montgomery–Asberg Depression Rating Scale (MADRS), Hamilton-Depression Rating Scale (HAM-D17), and other scales were administered before (T0) and after the latest 3-month stable trial (T3). Compared to ADs, the SGA+AD group showed increased percentage of depression with psychotic features, comorbidity for personality disorders and substance use disorders (SUD), higher number of failed ADs pharmacotherapies and depressive symptoms at T0 on all scales (P<0.001). Compared to T0, both treatments significantly decreased depressive symptoms on MADRS and HAM-D17 at T3 (P<0.001); however, the SGA+AD augmentation produced a greater decline in mean score. Logistic regression analysis indicated that psychotic features, personality disorders, and SUD were independently associated with SGA+AD treatment. Given the greater improvement in depression following SGA+AD augmentation, SGA augmentation should be indicated as a first-line treatment in severe TRD with psychotic features, SUD, and personality disorders.


American Journal of Psychiatry | 2001

Olanzapine-Induced Somnambulism

Theodore Kolivakis; Howard C. Margolese; Linda Beauclair; Guy Chouinard

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Linda Beauclair

McGill University Health Centre

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J. Scott Delaney

McGill University Health Centre

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Alain Dagher

Montreal Neurological Institute and Hospital

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