2_Drugs_7.docx

4/7/11: Drugs & Behavior Psych Comments on the Chronis Usage of Benzodiazepines: Benzodiazepines decrease anxiety and stress response acutely. Withdrawal from chronic benzodiazepines results in sever anxiety and panic. Many people are abusers of benzodiazepines. A newer ?atypical? drug buspirone (Buspar) is much more selective for anxiety, with fewer side effects. The basis of action appears to be that Buspar binds to 5-HT1a, and acts as a partial agonist. Behavioral Keys to the Treatment of Anxiety and Depression: Anxiety learn to relax! Depression interact with the environment Drug Treatment of Attention Disorder (ADHD): Symptoms: short attention span, easily distracted, poor impulse control, emotionally labile, aggressiveness, increased motor activity. Used to be called ?hyperactivity? or ?hyperkinetic disorder of childhood?. Now referred to as Attention deficit/ hyperactivity disorder (ADHD). Subtypes; inattentive; hyperactive impulsive, combined. Affects 2-10% of population. Affects adults as well as children. Drug Treatment of ADHD: Bradley 1937: noted the ?paradoxical effect of amphetamine?. Why was this effect viewed as ?paradoxical?? Because amphetamine is a stimulant (increase activity). Disordered was labeled ?hyperactivity?. With the shift in emphasis towards this disorder being an attentional disorder, the effect of stimulants such as amphetamine is no longer viewed as ?paradoxical?. Most common treatments for ADHD: Stimulants: Methylphenidate (Ritalin) D-amphetamine (Dexedrine) D- and l- amphetamine (Adderall) Methamphetamine (Dioxin) ? causes neurotoxicity (death of dopamine) Pemolime (Cylert) There have been more than 100 double-blind placebo-controlled studies showing that stimulants have efficacy in terms of either improved behavioral profile or improved attention performance. Some studies show improved performance in the classroom as measured by academic markers. Several studies suggest stimulants can be effectively combined with behavioral model. Problems with Drug Treatments for ADHD: Side effects: motor stimulant side effects, stereotypy, psychotic reactions, abuse potential, stunted growth. Overdiagnosis and Overprescription?!?! Some researchers maintained that overall the mental health service have gotten better at identifying these things. Long-term concern: What are the long-term consequences of being on stimulants for years? Downregulation of receptors? Downregulation of presynaptic neurotransmission? Neurotoxicity?!?! Brain Areas Implicated in ADHD: The precise neural pathology is unknown. Neuroimaging studies implicate several brain areas, including prefrontal cortex, cirgulate cortex, and basal ganglia. It is interesting to note that the stimulants used treat ADHD all act on DA and NE, the brain areas mentioned above all contain DA and NE terminals, or both. New treatments include DA or NE selective uptake inhibitors, which also are used as antidepressants. NE Uptake Blocker: Atomoxetine (Strattera) is a selective NE uptake blocker. Though it enhances attentional performance, it is not a psychomotor stimulant in the classic sense, and has limited abuse potential. Strattera was approved by the FDA for the treatment of ADHD in 2002. ADHD Booklet for Classroom Teachers ? Larry Silver, M.D. There is a lot of misinformation about ADHD. Drug Treatments for Alzheimer?s Disease and Alzheimer-Type Dementia: Both are neurodegenerative disorders affecting cognitive function. Alzheimer?s disease: affects ?younger? old people, i.e. <65 or <79; relatively rare. Senile Dementia of the Alzheimer?s type: affects older people, i.e., >65 or >79; extremely common. Drug Treatments for Alzheimer?s Disease and Alzheimer-Type Dementia: Symptoms: learning, memory, cognitive impairment; starts more as STM deficit in ?working? and ?episodic? memory, ends up also with reference memory (if you forgot where UConn is, meaning memory for something that doesn?t change, and is the same at all times) and memory for facts impaired; spatial disorientation, attentional dysfunction; problems with language (e.g., word finding). Neuropathology: Plaques: large abnormal structures in brain. Tangles: intracellular protein filaments. Neuronal Death: particularly in association neocortex, long projecting cells that connect neocortical areas. Neurotransmitter Depletions: Large loss of neocortical, hippocampal and amygdala Ach. Also NE, 5-HT loss in some patients. Acetylcholine and Cognition: Involvement of Ach in Alzheimer?s disease is consistent with research on involvement of Ach in learning/memory and attention. Loss of Ach cells in Alzheimer?s patients is correlated with cognitive impairment. Muscarinic antagonists (e.g., scopolamine, atropomine) are well known to impair working memory and attention in humans and other animals. Lesions that damage Ach cells that innervate neocortex and hippocampus in rats lead to cognitive impairments. Drug Treatments for Alzheimer?s Disease and Alzheimer-Type Dementia: In general drugs don?t work very well. Approved Drugs: Anticholinesterases: inhibition of acetylchoinesterase, which elevates extracellular levels of Ach. tacrine (Cognex) donepezil (Aricept) DA antagonists: e.g. Haldol - To block psychotic symptoms