Depression

Depression

1. Types:

   • Major depressive disorder:
     • Affects 5-10% of adults.
       • Majority of patients found in mainstream society.
         • Recognition is a collaborative effort
   • Situational depression
     • Result of circumstances in person's life.
   • Dysthymic disorder
     • Severe depression that may last several years.
       • Person does not "feel well".
         • May not function normally
   • Postpartum depression
     • Up to 80% of women experience it.
       • Caused by hormonal changes.
       • Prevalent enough that some state agencies mandate all new mothers receive info about mood shifts
   • Seasonal effective disorder
     • Enhanced release of melatonin r/t lower lvls of natural light.
       • May be relieved w/light therapy
   • Psychotic depression
     • Expression of intense mood shifts and unusual behaviors.
       • Depressive signs, loss of contact with reality, hallucinations, delusions, and disorganized speech.

2. Assessment & treatment

   • Corticosteroids, levodopa, and oral contraceptives can cause similar symptoms to depression
     • Rule out this possibility in health exam
   • Medical and neurologic disorders can also cause depressive symptoms.
     • This too
   • Ask about alcohol & drug use, family history.
   • Therapy:
     • Interpersonal:
       • Focuses on pt/ disturbed relationships
     • Cognitive-behavioral therapy:
       • Help pt, change negative styles of thought & behavior.
     • Psychodynamic:
       • Focus on resolving pt. internal conflict.
         • Postponed until symptoms are significantly improved
   • Electroconvulsive therapy is useful when therapy fails.
     • Over 70% show improvement
   • Transcranial magnetic stimulation may be an effective somatic treatment.
     • Surgical implant that does not effect memory, require general anesthetic, and is helpful w/o overt risk of generalized seizures

3. Antidepressants

   • Depression & anxiety are caused by similar neurotransmitter dysfunction.
     • Can also treat some pain
       • Closely monitor for warning signs of suicide, especially at beginning of treatment.
         • Children to young adults are at greater risk.
         • Also monitor for anxiety, panic attacks, agitation, irritability, insomnia, impulsivity, hostility, and mania.
   • Exerts effects through action on norepinephrine, serotonin, and dopamine.
     • Will either block breakdown of norepinephrine or slow reuptake of serotonin and norepinephrine
   • Selective serotonin repuptake inhibitors (SSRIs)
     • Same efficacy as MAOIs and TCAs
       • Advantage: greater safety profile, less sympathomimetic and anticholinergic effects, no cardiotoxicity.
         • Makes presynaptic neurons less sensitive to serotonin, but postsynaptic more sensitive
           • All drugs have equal efficacy and similar side effects.
             • Most common side effect is impotence.
               • Serotonin syndrome can result when combining an SSRi w/ an MAOI, a TCA, lithium, or any number of drugs
                 • Signs include confusion, anxiety, restlesness, hypertension, tremors, sweating, hyperpyrexia, or ataxia.
     • Serotonin is found in high concentrations in hypothalamus, limbic system , medulla, and spinal cord
       • Functions in cycling btwn REM and NREM sleep, pain perception & emotion
         • Inadequate amounts cause depression
     • Atypical antidepressants
       • Serotonin-norepinephrine reuptake inhibitors:
         • Includes duloxetine (Cymbalta) and venlafaxine (Effexor)
           • In many cases dopamine is also affected.
             • Duloxetine is also approved for GAD and neuropathic pain
               • Venlafaxine is also approved for GAD.
       • Bupropion (Wellbutrin)
         • Reuptakes serotonin and affects activity of norepinephrine and dopamine
           • Contraindicated in pt. w/seizure disorder
       • Mirtazapine (Remeron)
         • Blocks presynaptic serotonin and norepinephrine receptors
       • Nefazodone
         • Similar to mirtazapine
           • Causes minimal CV effects, fewer anticholinergic effects, less sedation, and less sexual dysfunction, but does cause hepatotoxicity
       • Trazodone (Oleptro)
         • Used to treat insomnia b/c high levels are needed for depression, and that causes sedation
       • Tricyclic antidepressnats
         • Inhibits presynaptic reuptake of norepinephrine and serotonin
           • Safer than MAOIs, but side effects still include orthostatic hypotension, cardiac dysrhythmia, dry mouth, constipation, blurred vision, and tachycardia.
             • Most have a long half life, increasing side effect risk.
               • Significant interactions w/ CNS depressants, sympathomimetics, anticolinergics, and MAOIs.
                 • Clomipramine (Anafranil) is used for OCD
                   • Doexpin (Sinequan) is for GAD, neuropathic pain, and fibromyalgia
                     • Some are used off label for panic disorder and social anxiety. Can be used for childhood bed wetting too.
         • Monoamine oxidase inhibitors
           • Decreases effectiveness of MAO, thus limiting breakdown of norepinephrine, epinephrine, dopamine, and serotonin
             • B/c of interactions , hepatotoxicity, and safer meds, these are reserved for pt. unresponsive to conventional treatment.
               • Common side effects are orthostatic hypotension, headache, insomnia, and diarrhea.
                 • Hypertensive crisis can occur w/antidepressants and sympathomimetic drugs.
                   • Serotonin syndrome can occur when combined w/SSRIs
                     • Severe hypotension when combined w/antihypertensives
                       • Potentiates hypoglycemic effects of insulin &oral antidiabetic drugs
               • When taken w/meperidine, dextromethorphan, or TCAs, hyperpyrexia can occur
                 • Hypertensive crisis can occur when combined w/foods containing tyramine.
                   • Tyramine is degraded by MAO in intestines, but if MAO is inhibited, it enters the bloodstream in high concentrations and displaces norepinephrine within presynaptic nerve terminals.
                     • Results in sudden release of norepinephrine.
                       • Occipital headache, stiff neck, flushing, palpations, diaphoresis, and nausea are symptoms.
                         • Mi and stroke can happen.
                           • Calcium channel blockers can be given as an antidote.