Understanding Depression Diagnosis, Neurobiology, and Treatment with Antidepressants, Slides of Psychology

Download Understanding Depression Diagnosis, Neurobiology, and Treatment with Antidepressants and more Slides Psychology in PDF only on Docsity! Antidepressants and Treatment of Mood Disorders Docsity.com Outline • Definitions • DSM-IV diagnoses and criteria • Epidemiology • Neurobiology • Psychosocial theories • Treatments Docsity.com Epidemiology • Depression is the most common cause of disability in the world • U.S. costs approximate 43$ billion per year for mood disorders • Lifetime prevalence rates: (according to NCS), 21-24% for women and 12-15% for men Docsity.com Major Depressive Disorder (MDD) • >2 week period of change in behavior with 5 of the following: – *depressed mood – *anhedonia – appetite disturbance – sleep disturbance – psychomotor disturbance – fatigue or loss of energy – worthlessness or guilt – impaired concentration – suicidal thoughts • * 1/5 symptoms must be these • Rule out physical cause Docsity.com Time Course of MDD • Often lasts for a year without treatment • Chances increase by 50% for another episode after current episode (i.e. high relapse and recurrence rates) • Many go on to experience chronic depression (but may be a result of inadequate treatment) Docsity.com Theories of Depression • NE and DA broken down to variety of products through MAO and COMT • 5HT is broken down by MAO to 5-HIAA • Major mechanism for terminating signal is neuronal reuptake • Monoaminergic Theories – Reserpine (early antihypertensive) – Iproniazid (used to treat TB) – Imipramine (originally studied as an antipsychotic) – Drugs enhancing noradrenergic functioning were antidepressants (eg. stimulants) Docsity.com Indoleamine Hypothesis of Depression • Serotonin is functionally deficient in depression – Decreased brain 5-HT and CSF 5-HIAA in many depressed patients – Antidepressants tend to increase central serotonin transmission – Depressed patients show reduction in 5-HT reuptake sites – Blunted neuroendocrine challenges Docsity.com Neurotransmitter Hypothesis of Mood Disorders • Led to catecholamine hypothesis – NE ↓ in depression and  in mania – 5-HT ↓ production or reuptake in depression • Flaws: depression or mania not reliably produced and clinical response exceeds mechanism of action of drug Docsity.com Neurobiology of Mood Disorders • Sleep abnormalities: usually found in endogenous depression – prolonged sleep latency – shortened REM latency and change in timing – increased wakefulness – decreased arousal threshold – early morning awakening – reduced stage 3 and 4 sleep Docsity.com Kindling-Sensitization Hypothesis of Mood Disorders • Suggests that repeated exposure to stress and/or neurochemical changes during depressed episode sensitize brain regions responsible for affect • Repeated episodes may permanently alter systems within the CNS • Leads to shorter well periods, increased frequency and severity of illness Docsity.com Treatments • Pharmacotherapy • Psychotherapy • Social interventions • ECT • TMS • VNS Docsity.com General Treatment Rules • Often takes 4-6 weeks for response • Monitor for response versus remission • Vegetative symptoms tend to improve first, cognitive symptoms take longer • SSRI’s are the first line of treatment for most MDD’s • Address biopsychosocial needs and maintain meds for 6-12 months Docsity.com Tricyclic Antidepressants • Available for more than 30 years • Cheap but not clean • Act by NE and/or 5 HT presynaptic reuptake inhibition • Side effects include anticholinergic effects, orthostasis, slowing of cardiac conduction • Secondary better than tertiary compounds Docsity.com Selective Serotonin Reuptake Inhibitors • Produce response rates close to 70% • Safer and better tolerated than TCA’s • Given once daily • Starting and therapeutic doses often similar • Most common side effects include GI symptoms, HA, insomnia, anxiety, and sexual dysfunction • Five available in the U.S. Docsity.com