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Evidence of Dysregulated Peripheral Oxytocin Release Among Depressed Women Jill M. Cyranowski, Ph.D. Western Psychiatric Institute and Clinic University of Pittsburgh Medical School. Oxytocin: Females, Affiliation and Stress. Mammalian neuropeptide
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Evidence of Dysregulated Peripheral Oxytocin Release Among Depressed Women Jill M. Cyranowski, Ph.D. Western Psychiatric Institute and Clinic University of Pittsburgh Medical School
Oxytocin: Females, Affiliation and Stress Mammalian neuropeptide Synthesized in hypothalamus, released both centrally and peripherally Associated with female reproductive function Uterine contractions, milk let-down Regulated by female reproductive hormones Facilitates affiliative behaviors Animal models of maternal caregiving and pair-bonding Released centrally and peripherally with stress Anxiolytic effects within animal models
Women’s Biobehavioral Responses to Stress Fight-or-Flight response Majority of supportive animal (and human) research conducted with males Tend-and-Befriend response (Taylor et al., 2000) Evolutionarily adaptive for females? Females more likely to affiliate with others when under stress Based on oxytocin-mediated attachment / caregiving system
Hormonal changes at puberty (role of oxytocin) Stress: Negative Life Events (esp. life events with interpersonal consequences) Female gender socialization Pubertal intensification in affiliative need Depressogenic Diathesis Anxiety Insecure parental attachments • high affiliative focus • low attachment security • high anxiety • low instrumentality Difficult adolescent transition Anxious/inhibited temperament Depression Low instrumental coping skills From Cyranowski et al. (2000), Archives of General Psychiatry
What we know about depression in women Timing of the Gender Gap in Depression Gender gap in MDD emerges at puberty OT role in female reproduction Anxious Depression in Women Gender gap in MDD appears to be differentially associated with anxious depression OT modulates anxiety and stress responses Interpersonal Stress Sensitivity Post-pubertal women display increased risk of depression with interpersonal life stress OT women’s “tend and befriend” stress response Increase threat of relationship gaps or loss? Elevated OT as indicator of social distress?
Oxytocin, Stress and Depression Postmortum human brain tissue Increased OT expressing neurons in PVN of depressed patients (Purba et al., 1996) Plasma levels in Depression Mixed findings: though high levels of patient heterogeneity in terms of gender, age, reproductive status, medication status, and methods of plasma sampling Short half-life of OT in plasma
Oxytocin Dysregulation and Depression in Women
Study Sample Inclusion Criteria Females, aged 20-40 Normal menstrual cycling; intact uterus Exclusion Criteria Pregnant, lactating, < than 6 mo post-partum Significant or unstable medical illness Taking hormone replacement Taking antidepressant medications Currently-Depressed Women SCID-IV criteria for current MDD episode HRSD > 14 at initial assessment Never-Depressed Women No current or lifetime history of mood disorder
Lab Procedures Lab protocol run at WPIC CNRC Sessions scheduled during follicular phase of menstrual cycle Testing sessions began at 2 pm Participants asked to abstain from eating, caffeine, smoking after 12:30 pm of test day Lab set-up Catheterization, BP monitor, EKG leds 25 minute habituation period
Study Design: Biobehavioral Mechanisms Of Depression in Women 20 min Rest Period Catheter Placed Blood draws q5 minutes 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 30 minute Resting Recovery 30 minute Resting Recovery 25 m Habituation 20 minute Resting Baseline 20 minute Resting Baseline 10 min TASK # 2 10 min TASK # 1
Assessments • Plasma Oxytocin • RIA of OT in plasma using previously published • methods (Amico et al., 1985) • Minimum detectable concentration = .5 pg/mL, • inter- and intra-assay coefficients of • variation < 10% • Sensitive, specific to 9-amino acid chain peptide • Depression and Anxiety • Clinician rated: HRSD-17 • Self-report: BDI, BAI • Interpersonal Function • Short-form of Inventory of Interpersonal • Problems (IIP; Horowitz et al., 1988, 1989)
Analysis Plan Total Oxytocin Concentrations Integrated Area Under the Curve (AUC), using trapezoidal approximation Utilized 2 (group) x 2 (task order) ANCOVA, controlling for age, current OC use Oxytocin Concentration and Interpersonal Function Partial correlations, controlling for task order, age, OC use Oxytocin Variability Evaluated within-task standard deviation (SD) of oxytocin levels obtained each subject Logistic regression models comparing subjects displaying high (SD > 1.5) versus low oxytocin SD
Individual OT Data: Affiliative Imagery Task Cyranowski et al., 2008
Individual OT Data: Stress Task Cyranowski et al., 2008
Results: OT Concentrations • For imagery task, group effect for OT concentration Depressed women displayed greater OT concentration [F(1,26)=7.9, p=.01] Effect persisted after controlling for age & OC use Cyranowski et al., 2008
Oxytocin Concentrations During Imagery * Non-transformed oxytocin levels, adjusted for age and oral contraceptive use
Results: OT Variability • Depressed women more likely to display elevated OT variability For each task, approximately one quarter of sample displayed elevated OT variability (SD > 1.5) % Displaying high OT variability, by Group Imagery Task: Wald statistic = 3.51, df=1, p=.06 Stress Task: Wald statistic = 4.46, df=1, p=.03
Associations between OT Concentration And Psychiatric and Interpersonal Factors
Depression and Peripheral OT: Conclusions • Depressed women more likely to display “dysregulated” pattern of peripheral OT release characterized by highly variable OT release Not all depressed women showed this pattern (only about 40%) Pattern characterized by pulsatile release and extremely brief half-life • Greater levels of dysregulation associated with greater symptoms of depression, anxiety, and interpersonal difficulties • No evidence of task-induced OT release • Cannot address central OT levels
Oxytocin, Depression And the Social Modulation Of Stress in Women
The Social Modulation of Stress • Do depressed and non-depressed women show differences in the social modulation of stress? If so, could this related to OT dysregulation?
The Social Modulation of Stress: Blood Pressure Response to Stress Task ▪ Group X Task Order interaction effect, F(1,32)=7.31, p=.01 Cyranowski et al., under review
The Social Modulation of Stress: Cortisol Response to Stress Task
Comparing Depressed Women With vs Without Evidence of OT Dysregulation: Cortisol Response to Stress Task
Depression and Social Modulation of Stress • Depression has long been associated with elevated levels of social or interpersonal dysfunction, social isolation, and reduced social support • In some contexts, elevations in peripheral oxytocin levels or dysregulated patterns of oxytocin release may represent a biomarker of social distress or unmet affiliative need Other data to support this interpretation?
Depression and Oxytocin: Recent Data • Taylor et al (2006, in press) • Elevated basal OT associated with relationship • gaps and difficulties, and elevated cortisol levels • In press, Psychological Science findings • Grippo et al (2007 cites, 2009) Female praire voles exposed to chronic • social isolation display: • Higher plasma OT • OT related brain differences • Depressed and anxious behavioral profiles
Grippo et al (2007): Higher Peripheral OT Levels Following Isolation
Grippo et al: OT-Related Brain and Behavioral Changes • Behavioral changes following social isolation Decreased sucrose intake (anhedonia?) Immobility in forced swim test (helplessness?) • Brain changes following social isolation • Significant increases in OT-immunoreactive • cell density in the hypothalamic PVN of socially • isolated female praire voles • Neuroendocrine responses in females may be especially sensitive to social isolation
Grippo et al: Depression Treatment Implications? Mean (+SEM) immobility time during a 5-min FST in paired or isolated prairie voles administered daily oxytocin (OT; 20 μg/50 μl/vole, SC) or vehicle (V; 50 μl/vole, SC)
Collaborators and Support Janet Amico, MD Ellen Frank, PhD Howard Seltman, MD, PhD Hou-Ming Cai, MD Tara Hofkens, BA Heather Spielvogle, MSW, John Scott, AM, Deb Stapf, BS, and Lynda Rose, BS Grant Support MH64144, MH30915 Clinical Neuroscience Research Center (RR0000056) Pittsburgh Mind-Body Center (HL076852/076858)