Anxiety disorders Anxiety disorders are very common:they are characterized by persistent generalized anxiety not related to any particular circumstance (once called'free floating anxiety').They occur in up to 4%of the general population at some time in their lives. Anxiety is more common in females than in males and the average age of onset is in the 20s and 30s.The state of anxiety can be well understood by considering its roots in Latin,anxietos -a painful mind,and Greek,anxo -to squeeze. The physiology of anxiety Anxiety is a normal phenomenon in the presence of danger and has evolved as a strategy to alert the organism to threats to its well-being.In physiological terms it was first described by Cannon (the originator of the term homeostasis)as the 'fight or flight reaction'.During this state the sympathetic nervous system is provoked into sustained and enhanced activity which readies the organism for life-preserving activity. Mass discharge of the sympathetic system causes a number of physiological and metabolic changes.An increased cardiac output is seletively directed to the muscles,whose increased metabolism is sustained by increased levels of blood glucose brought about by muscle glycolysis.Subjects report increased mental activity and a sense of being able to sustain increased physical activity. Emotional states can activate the sympathetic system physical stress For example,extreme anger or fear,emotions which like others arise in the hypothalamus,activates the reticular formation and hence the sympathetic system to a state ready for'fight or flight'.For animals,which is chosen depends on the particular situation,and the same was true of our primitive ancestors. Present-day humans encounter situations that call for an actual fight or flight less frequently than situations which provoke anxiety.In these situations, abnormally high levels of sympathetic activity,more suited to the primitive condition,are associated with anxiety disorders
Anxiety disorders Anxiety disorders are very common; they are characterized by persistent generalized anxiety not related to any particular circumstance (once called 'free floating anxiety'). They occur in up to 4% of the general population at some time in their lives. Anxiety is more common in females than in males and the average age of onset is in the 20s and 30s. The state of anxiety can be well understood by considering its roots in Latin, anxietos - a painful mind, and Greek, anxo - to squeeze. The physiology of anxiety Anxiety is a normal phenomenon in the presence of danger and has evolved as a strategy to alert the organism to threats to its well-being. In physiological terms it was first described by Cannon (the originator of the term homeostasis) as the 'fight or flight reaction'. During this state the sympathetic nervous system is provoked into sustained and enhanced activity which readies the organism for life-preserving activity. Mass discharge of the sympathetic system causes a number of physiological and metabolic changes. An increased cardiac output is selectively directed to the muscles, whose increased metabolism is sustained by increased levels of blood glucose brought about by muscle glycolysis. Subjects report increased mental activity and a sense of being able to sustain increased physical activity. Emotional states can activate the sympathetic system as well as physical stress. For example, extreme anger or fear, emotions which like others arise in the hypothalamus, activates the reticular formation and hence the sympathetic system to a state ready for 'fight or flight'. For animals, which is chosen depends on the particular situation, and the same was true of our primitive ancestors. Present-day humans encounter situations that call for an actual fight or flight less frequently than situations which provoke anxiety. In these situations, abnormally high levels of sympathetic activity, more suited to the primitive condition, are associated with anxiety disorders
Appropriate anxiety is normal:it is abnormal when it is out of proportion to the threat,whem it persists long after the threat has vanished or indeed is triggered by a situation generally thought to be harmless. In animals and man moderate anxiety improves mentation.However,the relationship between performnce and anxiety is described by what is sonetines known as the Yerks-Dodsom law which can be represented graphically. Some anxiety inproves performance but higher levels impair it.A good example of the Yerks-Dodson phenomenon is seen in students preparing for exaninations.Low levels of anxiety 8 weeks before the examination notivate the student to start revision.However,2 days before the examination,high levels of anxiety prevent sone people fron learning. The syaptoms of anxiety There are several psychological and physiological symptoms of anxiety and for clinical anxiety to be diagnosed a number must be present at the sane time. The mood of anxiety is one of apprehension or the expectation that there is some, frequently undefined,impending danger.The patient is in a state of tense alertness scanning the emvironment for signs of danger.The parallel between this picture and one of a prey animal in the vicinity of a predator is irresistible.There is a physiological increase in muscle tome and the patient may become visibly restless. Another common manifestation of anxiety is the symptom of breathlessness.which may provoke hypervemtilation resulting in hypocapnia and hypocalcaemia.This results in feelings of dixziness,paraesthesia and.if serun calcium falls by more than about 336,carpopedal spasm due to the hypocalcaemia causing increased excitability of the peripheral nerves.The hypocapnia of hyperventilation can be most simply relieved by calming the patient,encouraging slow regular breathing and if possible getting the patient to rebreathe air from a paper bag to retain carbon dioxide. Other common symptoms of anxiety include sweating.palpitations,tachycardia, diarrhoea and increased frequency of urination,all of which have their physiological basis in increased discharge of the sympathetic system.In addition to fearfulness,the patient may describe psychological symptons of insomnia
Appropriate anxiety is normal; it is abnormal when it is out of proportion to the threat, when it persists long after the threat has vanished or indeed is triggered by a situation generally thought to be harmless. In animals and man moderate anxiety improves mentation. However, the relationship between performance and anxiety is described by what is sometimes known as the Yerks-Dodson law which can be represented graphically. Some anxiety improves performance but higher levels impair it. A good example of the Yerks-Dodson phenomenon is seen in students preparing for examinations. Low levels of anxiety 8 weeks before the examination motivate the student to start revision. However, 2 days before the examination, high levels of anxiety prevent some people from learning. The symptoms of anxiety There are several psychological and physiological symptoms of anxiety and for clinical anxiety to be diagnosed a number must be present at the same time. The mood of anxiety is one of apprehension or the expectation that there is some, frequently undefined, impending danger. The patient is in a state of tense alertness scanning the environment for signs of danger. The parallel between this picture and one of a prey animal in the vicinity of a predator is irresistible. There is a physiological increase in muscle tone and the patient may become visibly restless. Another common manifestation of anxiety is the symptom of breathlessness, which may provoke hyperventilation resulting in hypocapnia and hypocalcaemia. This results in feelings of dizziness, paraesthesia and, if serum calcium falls by more than about 33%, carpopedal spasm due to the hypocalcaemia causing increased excitability of the peripheral nerves. The hypocapnia of hyperventilation can be most simply relieved by calming the patient, encouraging slow regular breathing and if possible getting the patient to rebreathe air from a paper bag to retain carbon dioxide. Other common symptoms of anxiety include sweating, palpitations, tachycardia, diarrhoea and increased frequency of urination, all of which have their physiological basis in increased discharge of the sympathetic system. In addition to fearfulness, the patient may describe psychological symptoms of insomnia
exaggerated responses to being startled,a sense of unreality and increased irritability. Treatment of anxiety disorders Patients have often suffered for several years hefore they present with syrptoms of anxiety.Treatnent is therefore frequently not straightforward as the patient may have grossly nodified his life to avoid situations that trigger attacks. There may be therapeutic behavioural changes which can be made.for example to reorganize a pressured work schedule.Education to reduce the fear of palpitations and tachycardia often belps.Relaxation and anxiety management training are widely employed to reduce symptoms.If behavioural and cognitive approaches fail. pharnacological treatsent can be used with varying success. Benzodiazepines These are probbly the most commonly used anxiolytics.although fears of dependency developing have limited their use.Benzodiazepines act at y-aminobutyric acid (GABA)receptors to potentiate their action.GABA is found throughout the brain as an inhibitory transnitter.The fact that benzodiaxepines modulate GABA activity suggests that there might be an endogenous ligand which night naturally act at the bemzodiazepine receptor.Benzodiazepines are rapidly absorbed from the gut and eliminated by conjugation in the liver.Reduced hepatic function with age mandates care in their use with the elderly.Bemzodiazepines act as sedatives and anticomrulsants.Their most serious side-effects include dependence and tolerance. Tricyclic antidepressants and S5RIs (selective serotonin reuptake inhibitors) Depression is often seen vith anxiety.These drugs,used in depression,have significant anxiolytic effects though the relationship betveen the two effects remains unclear.Their physiological action is to selectively inhibit the reuptake of serotonin (5-hydroxytryptanine.5-HT)and noradrenaline by presynaptic neurones in the brafn. B-blockers
exaggerated responses to being startled, a sense of unreality and increased irritability. Treatment of anxiety disorders Patients have often suffered for several years before they present with symptoms of anxiety. Treatment is therefore frequently not straightforward as the patient may have grossly modified his life to avoid situations that trigger attacks. There may be therapeutic behavioural changes which can be made, for example to reorganize a pressured work schedule. Education to reduce the fear of palpitations and tachycardia often helps. Relaxation and anxiety management training are widely employed to reduce symptoms. If behavioural and cognitive approaches fail, pharmacological treatment can be used with varying success. Benzodiazepines These are probably the most commonly used anxiolytics, although fears of dependency developing have limited their use. Benzodiazepines act at γ-aminobutyric acid (GABA) receptors to potentiate their action. GABA is found throughout the brain as an inhibitory transmitter. The fact that benzodiazepines modulate GABA activity suggests that there might be an endogenous ligand which might naturally act at the benzodiazepine receptor. Benzodiazepines are rapidly absorbed from the gut and eliminated by conjugation in the liver. Reduced hepatic function with age mandates care in their use with the elderly. Benzodiazepines act as sedatives and anticonvulsants. Their most serious side-effects include dependence and tolerance. Tricyclic antidepressants and SSRIs (selective serotonin reuptake inhibitors) Depression is often seen with anxiety. These drugs, used in depression, have significant anxiolytic effects though the relationship between the two effects remains unclear. Their physiological action is to selectively inhibit the reuptake of serotonin (5-hydroxytryptamine, 5-HT) and noradrenaline by presynaptic neurones in the brain. β-blockers
B-adremoceptor antagonists such as propranolol can be used in the treatment of anxiety.Work with masicians anxious before a performance sugcests that it is the reduction of tremor.which presumably acts as a feedback signal of anxiety. rather than any effeet on the enotional component that produces the bemeficlal effect. Side-effects linit the usefulness of these drugs in anxiety. Baspirone Serotonin-containing neurones in parts of the raphe nucleus appear to be involved in the types of behavioural activity seen in anxiety.Buspirome is an antagonist at 5-HTu receptors and exerts powerful anxiolytic actions.These effects are very slow to develop,taking up to 3 weeks,which sugcests that their action is indirect rather than a straightforward pharmacological block at receptor 81108- Most patients who have anxiety disorders will benefit fron a combined pharnscological and psychological approach.Progress depends on the type of anxiety disorder but in many cases the condition is troublesone to treat,presenting as it often does in the chronic phase of the disorder
β-adrenoceptor antagonists such as propranolol can be used in the treatment of anxiety. Work with musicians anxious before a performance suggests that it is the reduction of tremor, which presumably acts as a feedback signal of anxiety, rather than any effect on the emotional component that produces the beneficial effect. Side-effects limit the usefulness of these drugs in anxiety. Buspirone Serotonin-containing neurones in parts of the raphe nucleus appear to be involved in the types of behavioural activity seen in anxiety. Buspirone is an antagonist at 5-HT1A receptors and exerts powerful anxiolytic actions. These effects are very slow to develop, taking up to 3 weeks, which suggests that their action is indirect rather than a straightforward pharmacological block at receptor sites. Most patients who have anxiety disorders will benefit from a combined pharmacological and psychological approach. Progress depends on the type of anxiety disorder but in many cases the condition is troublesome to treat, presenting as it often does in the chronic phase of the disorder