Transcript PPT 1
Biomedical Therapies Antipsychotic Drugs • Antipsychotic drugs (like Thorazine, Mellaril, and Haldol) are used to gradually reduce psychotic symptoms, including hyperactivity, mental confusion, hallucinations, and delusions. • Antipsychotic drugs appear to decrease activity at dopamine synapses, sometimes producing unfortunate side-effects such as symptoms of Parkinson’s disease and tardive dyskinesia, an incurable neurological disorder marked by involuntary writhing and tick-like movements of the mouth, tongue, face, hands, or feet. • • But: not risk-free; may cause seizures or blood disorders in some, diabetes or weight-gain in other s Classical vs. Atypical Antipsychotics • Classical antipsychotics [chlorpromazine (sold as Thorazine)]: Remove a number of positive symptoms associated with schizophrenia such as agitation, delusions, and hallucinations. • Atypical antipsychotics [clozapine (sold as Clozaril)]: Blocks receptors for dopamine and serotonin to remove the negative symptoms associated with schizophrenia such as apathy, jumbled thoughts, concentration difficulties, and difficulties in interacting with others. They enable “awakenings.” – These newer drugs, which have a different mechanism of action, have fewer motor side effects but are not risk free. They may increase the risk of obesity and diabetes. Anti-Anxiety Drugs • Antianxiety drugs depress the central nervous system and reduce anxiety, apprehension, nervousness, and tension by elevating neurotransmitter levels. • Most widely abused drugs. Anti-Anxiety Drugs • Traditional Antianxiety Drugs Best known = benzodiazepine tranquilizers • • Examples: Librium, Valium (diazepam), Xanax (alprazolam) and Ativan • These depressant drugs decrease anxiety disorder symptoms and treat insomnia. • But: can impair memory; interact with alcohol; can cause dependency at higher doses or with longer use Usually takes a week to fully work but can work for acute situations, like a panic attack Antidepressant Drugs • Antidepressants gradually elevate mood and help bring people out of a depression. They improve the mood by elevating levels of serotonin by inhibiting reuptake. • The 3 major classes of antidepressant drugs include: – Tricyclics – Elavil, Tofranil – Mao inhibitors (MAOIs) – Nardil – Selective serotonin reuptake inhibitors (SSRIs) – Prozac, Paxil, Zoloft • Today, the SSRIs are the most frequently prescribed. Figure 15.12: Antidepressant drugs’ mechanisms of action. The three types of antidepressant drugs all increase activity at serotonin synapses, which is probably the principal basis for their therapeutic effects. However, they increase serotonin activity in different ways, with different spillover effects (Marangell et al. 1999). Tricyclics and MAO inhibitors have effects at a much greater variety of synapses, which presumably explains why they have more side effects. The more recently developed SSRIs are more specific in targeting serotonin synapses. SSRIs – Prozac, Paxil, Zoloft • SSRI’s are equally effective, less annoying side effects, & almost suicide -proof • Antidepressants take ~4-6 weeks to produce their effects • 65-70% show significant improvement • These drugs can also improve anxiety disorders Best when used with severely depressed patients • Antidepressants are now also used to treat anxiety, OCD, and PTSD Mood-Stabilizing Medications • Lithium Carbonate, a common salt, has been used to stabilize manic episodes in bipolar disorders. • It moderates the levels of norepinephrine and glutamate neurotransmitters. • is used to treat patients with bipolar mood disorders to control mood swings. The drug may have dangerous side effects, however, such as kidney and thyroid damage. • Best known treatment for bipolar disorder: Lithium Surprisingly anticonvulsants are an effective alternative. • Sometimes a combination of meds is necessary. Powerful side effects that vary but can be toxic if over ingested. Electroconvulsive Therapy (ECT) • • ECT is used for severely depressed patients who do not respond to drugs. • The patient is anesthetized & given a muscle relaxant. • Patients usually get 30-60 seconds of electrical current that relieves them of depression. • Side Effects: using today's methods of ECT, very small/limited effect on memory – YET…much of the public still worries about the safety of ECT • About 4 in 10 ECT-treated patients relapse into depression within 6 months Repetitive Transcranial Magnetic Stimulation (rTMS) • In rTMS, a pulsating magnetic coil is placed over prefrontal regions of the brain to treat depression with minimal side effects. • How does it work? One possible explanation is that the stimulation energizes depressed patients’ relatively inactive left frontal lobe Lobotomy Lobotomy is a procedure that cuts the nerves connecting the frontal lobes to the thalamus • Portuguese neurologist Egas Moniz developed it in 1935 to help uncontrollably emotional and violent patients • • In 1945, American neurologist Walter Freeman developed the transorbital lobotomy, which used an ice pick through the eye socket to damage the neural connections.