Psychiatrists like to categorise mental illnesses because mental signs and symptoms do occur together in clusters or syndromes, each tending to respond to certain treatments. The idea that illnesses can be diagnosed simply by recognising their symptom patterns may not seem very scienti?c in these days of high technology. For most common mental illnesses, however, this is the only method of diagnosis; whatever is going wrong in the brain is usually too poorly understood and too subtle to show up in laboratory tests or computed tomography scans of the brain. And symptom-based definitions of mental illnesses are, generally, a lot more meaningful than the vague lay term ‘nervous breakdown’, which is used to cover an attack of anything from AGORAPHOBIA to total inability to function.
There is still a lot to learn about the workings of the brain, but psychiatry has developed plenty of practical knowledge about the probable causes of mental illness, ways of relieving symptoms, and ways of aiding recovery. Most experts now believe that mental illnesses generally arise from di?erent combinations of inherited risk and psychological STRESS, sometimes with additional environmental exposure – for example, viruses, drugs or ALCOHOL.
The range of common mental illnesses includes anxiety states, PHOBIA, DEPRESSION, alcohol and drug problems, the EATING DISORDERS anorexia and bulimia nervosa, MANIC DEPRESSION, SCHIZOPHRENIA, DEMENTIA, and a group of problems related to coping with life that psychiatrists call personality disorders.
Of these mental illnesses, dementia is the best understood. It is an irreversible and fatal form of mental deterioration (starting with forgetfulness and eventually leading to severe failure of all the brain’s functions), caused by rapid death of brain cells and consequent brain shrinkage. Schizophrenia is another serious mental illness which disrupts thought-processes, speech, emotions and perception (how the brain handles signals from the ?ve senses). Manic depression, in which prolonged ‘highs’ of extremely elevated mood and overexcitement alternate with abject misery, has similar effects on the mental processes. In both schizophrenia and manic depression the sufferer loses touch with reality, develops unshakeable but completely unrealistic ideas (delusions), and hallucinates (vividly experiences sensations that are not real, e.g. hears voices when there is nobody there). This triad of symptoms is called psychosis and it is what lay people, through fear and lack of understanding, sometimes call lunacy, madness or insanity.
The other mental illnesses mentioned above are sometimes called neuroses. But the term has become derogatory in ordinary lay language; indeed, many people assume that neuroses are mild disorders that only affect weak people who cannot ‘pull themselves together’, while psychoses are always severe. In reality, psychoses can be brief and reversible and neuroses can cause lifelong disability.
However de?ned and categorised, mental illness is a big public-health problem. In the UK, up to one in ?ve women and around one in seven men have had mental illness. About half a million people in Britain suffer from schizophrenia: it is three times commoner than cancer. And at any one time, up to a tenth of the adult population is ill with depression.
Treatment settings Most people with mental-health problems get the help they need from their own family doctor(s), without ever seeing a psychiatrist. General practictitioners in Britain treat nine out of ten recognised mental-health problems and see around 12 million adults with mental illness each year. Even for the one in ten of these patients referred to psychiatrists, general practitioners usually handle those problems that continue or recur.
Psychiatrists, psychiatric nurses, social workers, psychologists, counsellors and therapists often see patients at local doctors’ surgeries and will do home visits if necessary. Community mental-health centres – like general-practice health centres but catering solely for mental-health problems – o?er another short-cut to psychiatric help. The more traditional, and still more common, route to a psychiatrist for many people, however, is from the general practititioner to a hospital outpatient department.
Specialist psychiatric help In many ways, a visit to a psychiatrist is much like any trip to a hospital doctor – and, indeed, psychiatric clinics are often based in the outpatient departments of general hospitals. First appointments with psychiatrists can last an hour or more because the psychiatrist – and sometimes other members of the team such as nurses, doctors in training, and social workers – need to ask lots of questions and record the whole consultation in a set of con?dential case notes.
Psychiatric assessment usually includes an interview and an examination, and is sometimes backed up by a range of tests. The interview begins with the patient’s history – the personal story that explains how and, to some extent, why help is needed now. Mental-health problems almost invariably develop from a mixture of causes – emotional, social, physical and familial – and it helps psychiatrists to know what the people they see are normally like and what kind of lives they have led. These questions may seem unnecessarily intrusive, but they allow psychiatrists to understand patients’ problems and decide on the best way to help them.
The next stage in assessment is the mental-state examination. This is how psychiatrists examine minds, or at least their current state. Mental-state examination entails asking more questions and using careful observation to assess feelings, thoughts and mental symptoms, as well as the way the mind is working (for example, in terms of memory and concentration). During ?rst consultations psychiatrists usually make diagnoses and explain them. The boundary between a life problem that will clear up spontaneously and a mental illness that needs treatment is sometimes quite blurred; one consultation may be enough to put the problem in perspective and help to solve it.
Further assessment in the clinic may be needed, or some additional tests. Simple blood tests can be done in outpatient clinics but other investigations will mean referral to another department, usually on another day.
Further assessment and tests
PSYCHOLOGICAL TESTS Psychologists work in or alongside the psychiatric team, helping in both assessment and treatment. The range of psychological tests studies memory, intelligence, personality, perception and capability for abstract thinking. PHYSICAL TESTS Blood tests and brain scans may be useful to rule out a physical illness causing psychological symptoms. SOCIAL ASSESSMENT Many patients have social diffculties that can be teased out and helped by a psychiatric social worker. ‘Approved social workers’ have special training in the use of the Mental Health Act, the law that authorises compulsory admissions to psychiatric hospitals and compulsory psychiatric treatments. These social workers also know about all the mental-health services o?ered by local councils and voluntary organisations, and can refer clients to them. The role of some social workers has been widened greatly in recent years by the expansion of community care. OCCUPATIONAL THERAPY ASSESSMENT Mental-health problems causing practical disabilities – for instance, inability to work, cook or look after oneself – can be assessed and helped by occupational therapists.
Treatment The aims of psychiatric treatment are to help sufferers shake o?, or at least cope with, symptoms and to gain or regain an acceptable quality of life. A range of psychological and physical treatments is available.
COUNSELLING This is a widely used ‘talking cure’, particularly in general practice. Counsellors listen to their clients, help them to explore feelings, and help them to ?nd personal and practical solutions to their problems. Counsellors do not probe into clients’ pasts or analyse them. PSYCHOTHERAPY This is the best known ‘talking cure’. The term psychotherapy is a generalisation covering many di?erent concepts. They all started, however, with Sigmund Freud (see FREUDIAN THEORY), the father of modern psychotherapy. Freud was a doctor who discovered that, as well as the conscious thoughts that guide our feelings and actions, there are powerful psychological forces of which we are not usually aware. Applying his theories to his patients’ freely expressed thoughts, Freud was able to cure many illnesses, some of which had been presumed completely physical. This was the beginning of individual analytical psychotherapy, or PSYCHOANALYSIS. Although Freud’s principles underpin all subsequent theories about the psyche, many di?erent schools of thought have emerged and in?uenced psychotherapists (see ADLER; JUNGIAN ANALYSIS; PSYCHOTHERAPY). BEHAVIOUR THERAPY This springs from theories of human behaviour, many of which are based on studies of animals. The therapists, mostly psychologists, help people to look at problematic patterns of behaviour and thought, and to change them. Cognitive therapy is very e?ective, particularly in depression and eating disorders. PHYSICAL TREATMENTS The most widely used physical treatments in psychiatry are drugs. Tranquillising and anxiety-reducing BENZODIAZEPINES like diazepam, well known by its trade name of Valium, were prescribed widely in the 1960s and 70s because they seemed an e?ective and safe substitute for barbiturates. Benzodiazepines are, however, addictive and are now recommended only for short-term relief of anxiety that is severe, disabling, or unacceptably distressing. They are also used for short-term treatment of patients drying out from alcohol.
ANTIDEPRESSANT DRUGS like amitriptyline and ?uoxetine are given to lift depressed mood and to relieve the physical symptoms that sometimes occur in depression, such as insomnia and poor appetite. The side-effects of antidepressants are mostly relatively mild, when recommended doses are not exceeded – although one group, the monoamine oxidase inhibitors, can lead to sudden and dangerous high blood pressure if taken with certain foods.
Manic depression virtually always has to be treated with mood-stabilising drugs. Lithium carbonate is used in acute mania to lower mood and stop psychotic symptoms; it can also be used in severe depression. However lithium’s main use is to prevent relapse in manic depression. Long-term unwanted effects may include kidney and thyroid problems, and short-term problems in the nervous system and kidney may occur if the blood concentration of lithium is too high – therefore it must be monitored by regular blood tests. Carbamazepine, a treatment for EPILEPSY, has also been found to stabilise mood, and also necessitates blood tests.
Antipsychotic drugs, also called neuroleptics, and major tranquillisers are the only e?ective treatments for relieving serious mental illnesses with hallucinations and delusions. They are used mainly in schizophrenia and include the short-acting drugs chlorpromazine and clozapine as well as the long-lasting injections given once every few weeks like ?uphenazine decanoate. In the long term, however, some of the older antipsychotic drugs can cause a brain problem called TARDIVE DYSKINESIA that affects control of movement and is not always reversible. And the antipsychotic drugs’ short-term side-effects such as shaking and sti?ness sometimes have to be counteracted by other drugs called anticholinergic drugs such as procyclidine and benzhexol. Newer antipsychotic drugs such as clozapine do not cause tardive dyskinesia, but clozapine cannot be given as a long-lasting injection and its concentration in the body has to be monitored by regular blood tests to avoid toxicity. OTHER PHYSICAL TREATMENTS The other two physical treatments used in psychiatry are particularly controversial: electroconvulsive therapy (ECT) and psychosurgery. In ECT, which can be life-saving for patients who have severe life-threatening depression, a small electric current is passed through the brain to induce a ?t or seizure. Before the treatment the patient is anaesthetised and given a muscle-relaxing injection that reduces the magnitude of the ?t to a slight twitching or shaking. Scientists do not really understand how ECT works, but it does, for carefully selected patients. Psychosurgery – operating on the brain to alleviate psychiatric illness or di?cult personality traits – is extremely uncommon these days. Stereo-tactic surgery, in which small cuts are made in speci?c brain ?bres under X-ray guidance, has super-seded the more generalised lobotomies of old. The Mental Health Act 1983 ensures that psychosurgery is performed only when the patient has given fully informed consent and a second medical opinion has agreed that it is necessary. For all other psychiatric treatments (except another rare treatment, hormone implantation for reducing the sex drive of sex o?enders), either consent or a second opinion is needed – not both. TREATMENT IN HOSPITAL Psychiatric wards do not look like medical or surgical wards and sta? may not wear uniforms. Patients do not need to be in their beds during the day, so the beds are in separate dormitories. The main part of most wards is a living space with a day room, an activity and television room, quiet rooms, a dining room, and a kitchen. Ward life usually has a certain routine. The day often starts with a community meeting at which patients and nurses discuss issues that affect the whole ward. Patients may go to the occupational therapy department during the day, but there may also be some therapy groups on the ward, such as relaxation training. Patients’ symptoms and problems are assessed continuously during a stay in hospital. When patients seem well enough they are allowed home for trial periods; then discharge can be arranged. Patients are usually followed up in the outpatient clinic at least once.
TREATING PATIENTS WITH ACUTE PSYCHIATRIC ILLNESS Psychiatric emergencies – patients with acute psychiatric illness – may develop from psychological, physical, or practical crises. Any of these crises may need quick professional intervention. Relatives and friends often have to get this urgent help because the sufferer is not ?t enough to do it or, if psychotic, does not recognise the need. First, they should ring the person’s general practitioner. If the general practitioner is not available and help is needed very urgently, relatives or friends should phone the local social-services department and ask for the duty social worker (on 24-hour call). In a dire emergency, the police will know what to do.
Any disturbed adult who threatens his or her own or others’ health and safety and refuses psychiatric help may be moved and detained by law. The Mental Health Act of 1983 authorises emergency assessment and treatment of any person with apparent psychiatric problems that ful?l these criteria.
Although admission to hospital may be the best solution, there are other ways that psychiatric services can respond to emergencies. In some districts there are ‘crisis intervention’ teams of psychiatrists, nurses, and social workers who can visit patients urgently at home (at a GP’s request) and, sometimes, avert unnecessary admission. And research has shown that home treatment for a range of acute psychiatric problems can be e?ective.
LONG-TERM TREATMENT AND COMMUNITY CARE Long-term treatment is often provided by GPs with support and guidance from psychiatric teams. That is ?ne for people whose problems allow them to look after themselves, and for those with plenty of support from family and friends. But some people need much more intensive long-term treatment and many need help with running their daily lives.
Since the 1950s, successive governments have closed the old psychiatric hospitals and have tried to provide as much care as possible outside hospital – in ‘the community’. Community care is e?ective as long as everyone who needs inpatient care, or residential care, can have it. But demand exceeds supply. Research has shown that some homeless people have long-term mental illnesses and have somehow lost touch with psychiatric services. Many more have developed more general long-term health problems, particularly related to alcohol, without ever getting help.
The NHS and Community Care Act 1990, in force since 1993, established a new breed of professionals called care managers to assess people whose long-term illnesses and disabilities make them unable to cope completely independently with life. Care managers are given budgets by local councils to assess people’s needs and to arrange for them tailor-made packages of care, including services like home helps and day centres. But co-ordination between health and social services has sometimes failed – and resources are limited – and the government decided in 1997 to tighten up arrangements and pool community-care budgets.
Since 1992 psychiatrists have had to ensure that people with severe mental illnesses have full programmes of care set up before discharge from hospital, to be overseen by named key workers. And since 1996 psychiatrists have used a new power called Supervised Discharge to ensure that the most vulnerable patients cannot lose touch with mental-health services. There is not, however, any law that allows compulsory treatment in the community.
There is ample evidence that community care can work and that it need not cost more than hospital care. Critics argue, however, that even one tragedy resulting from inadequate care, perhaps a suicide or even a homicide, should reverse the march to community care. And, according to the National Schizophrenia Fellowship, many of the 10–15 homicides a year carried out by people with severe mental illnesses result from inadequate community care.
Further information can be obtained from the Mental Health Act Commission, and from MIND, the National Association for Mental Health. MIND also acts as a campaigning and advice organisation on all aspects of mental health.... mental illness
(2) An agent, for example a drug, that acts with another to produce a result that is greater than adding together the separate effects of the two agents. Synergism in drug treatment may be bene?cial, as in the case of combined LEVODOPA and SELEGILINE, a selective monoamine oxidase inhibitor (see MONOAMINE OXIDASE INHIBITORS (MAOIS), in the treatment of PARKINSONISM. It may be potentially dangerous, however, as when MAOIs boost the effects of BARBITURATES.... synergist
Symptoms: low blood pressure, skin lesions, toxaemia, collapse.
Treatment. Same as for ERYTHEMA NODOSUM. Local antipruritics to relieve irritation. ... erythema multiform
The Misuse of Drugs Regulations 1985 de?ne the classes of person authorised to supply and possess controlled drugs, and lay down the conditions under which these activities may be carried out. In the Regulations, drugs are divided into ?ve schedules specifying the requirements for supply, possession, prescribing and record-keeping. Schedule I contains drugs which are not used as medicines. Schedules II and III contain drugs which are subject to the prescription requirements of the Act (see below). They are distinguished in the British National Formulary (BNF) by the symbol CD and they include morphine, diamorphine (heroin), other opioid analgesics, barbiturates, amphetamines, cocaine and diethylpropion. Schedules IV and V contain drugs such as the benzodiazepines which are subject to minimal control. A full list of the drugs in each schedule can be found in the BNF.
Prescriptions for drugs in schedules II and III must be signed and dated by the prescriber, who must give his or her address. The prescription must be in the prescriber’s own handwriting and provide the name and address of the patient and the total quantity of the preparation in both words and ?gures. The pharmacist is not allowed to dispense a controlled drug unless all the information required by law is given on the prescription.
Until 1997 the Misuse of Drugs (Noti?cation and Supply of Addicts) Regulations 1973 governed the noti?cation of addicts. This was required in respect of the following commonly used drugs: cocaine, dextromoramide, diamorphine, dipipanone, hydrocodeine, hydromorphone, levorphanol, methadone, morphine, opium, oxycodone, pethidine, phenazocine and piritranide.
In 1997 the Misuse of Drugs (Supply to Addicts) Regulations 1997 revoked the 1973 requirement for noti?cation. Doctors are now expected to report (on a standard form) cases of drug misuse to their local Drug Misuse Database (DMD). Noti?cation by the doctor should be made when a patient ?rst presents with a drug problem or when he or she visits again after a gap of six months or more. All types of misuse should be reported: this includes opioids, benzodiazepines and central nervous system stimulants. The data in the DMD are anonymised, which means that doctors cannot check on possible multiple prescribing for drug addicts.
The 1997 Regulations restrict the prescribing of diamorphine (heroin), Diconal® (a morphine-based drug) or cocaine to medical practitioners holding a special licence issued by the Home Secretary.
Fuller details about the prescription of controlled drugs are in the British National Formulary, updated twice a year, and available on the Internet (see www.bnf.org).... controlled drugs
The interaction may take place:
(1) Prior to absorption or administration – for example, antacids bind tetracycline in the gut and prevent absorption.
(2) By interfering with protein binding – one drug may displace another from binding sites on plasma proteins. The action of the displaced drug will be increased because more drug is now available; for example, anticoagulants are displaced by analgesics.
(3) During metabolism or excretion of the drug – some drugs increase or decrease the activity of liver enzymes which metabolise drugs, thus affecting their rate of destruction; for example, barbiturates, nicotine, and alcohol all activate hepatic enzymes. Altering the pH of urine will affect the excretion of drugs via the kidney.
(4) At the drug receptor – one drug may displace another at the receptor, affecting its e?cacy or duration of action.... drug interactions
If required in states of chronic distress, whether induced by disease or environment, it is especially important to limit the drugs to a short time to prevent undue reliance on them, and to prevent the use of hypnotics and sedatives from becoming a means of avoiding the patient’s real problem. In many cases, such as chronic depression, overwork, and alcohol abuse, hypnotics are quite inappropriate; some form of counselling and relaxation therapy is preferable.
Hypnotics should always be chosen and prescribed with care, bearing in mind the patient’s full circumstances. They are generally best avoided in the elderly (confusion is a common problem), and in children – apart from special cases. Barbiturates should not now be used as they tend to be addictive. The most commonly used hypnotics are the BENZODIAZEPINES such as nitrazepam and temazepam; chloral derivatives, while safer for the few children who merit them, are generally second choice and should be used in the lowest possible dose for the minimum period.
Side-effects include daytime drowsiness – which may interfere with driving and other skilled tasks – and insomnia following withdrawal, especially after prolonged use, is a hazard. Occasionally benzodiazepines will trigger hostility and aggression. Zolpidem and zopiclone are two drugs similar to the benzodiazepines, indicated for short-term treatment of insomnia in the elderly. Adverse effects include confusion, incoordination and unsteadiness, and falls have been reported.
FLUNITRAZEPAM is a tranquilliser/hypnotic that has been misused as a recreational drug.... hypnotics
Misuse of Drugs Act 1971 This legislation forbids activities relating to the manufacture, sale and possession of particular (controlled) drugs. These are classi?ed into three grades according to their dangers if misused. Any o?ences concerning class A drugs, potentially the most damaging when abused, carry the toughest penalties, while classes B and C attract lesser penalties if abused.
Class A includes: cocaine, dextromoramide, diamorphine (heroin), lysergic acid (LSD), methadone, morphine, opium, pethidine, phencyclidine acid and injectable preparations of class B drugs.
Class B includes: oral amphetamines, barbiturates, codeine, glutethimide, marijuana (cannabis), pentazocine and pholcodine.
Class C includes: drugs related to the amphetamines, anabolic and androgenic steroids, many benzodiazepines, buprenorphine, diethyl propion, human chorionic gonadotrophin (HCG), mazindol, meprobamate, pemoline, phenbuterol, and somatropin.
Misuse of Drugs Regulations 1985 These regulations de?ne those people who are authorised in their professional capacity to supply and possess controlled drugs. They also describe the requirements for legally undertaking these activities, such as storage of the drugs and limits on their prescription.
Drugs are divided into ?ve schedules and some examples follow.
I: Almost all are prohibited except in accordance with Home O?ce authority: marijuana (cannabis), LSD.
II: High potential for abuse but have
accepted medical uses: amphetamines, cocaine.
III: Lower potential for abuse: barbiturates, meprobamate, temazepam.
IV: Lower potential for abuse than I to III. Minimal control: benzodiazepines.
V: Low potential for abuse: generally compound preparations containing small amounts of opioids: kaolin and morphine (antidiarrhoeal medicine), codeine linctus (cough suppressant).
(See also CONTROLLED DRUGS.)... misuse of drugs
There are three main categories of licensed medicinal product. Drugs in small quantities can, if they are perceived to be safe, be licensed for general sale (GSL – general sales list), and may then be sold in any retail shop. P (pharmacy-only) medicines can be sold from a registered pharmacy by or under the supervision of a pharmacist (see PHARMACISTS); no prescription is needed. P and GSL medicines are together known as OTCs – that is, ‘over-thecounter medicines’. POM (prescription-only medicines) can only be obtained from a registered pharmacy on the prescription of a doctor or dentist. As more information is gathered on the safety of drugs, and more emphasis put on individual responsibility for health, there is a trend towards allowing drugs that were once POM to be more widely available as P medicines. Examples include HYDROCORTISONE 1 per cent cream for skin rashes, CIMETIDINE for indigestion, and ACICLOVIR for cold sores. Care is needed to avoid taking a P medicine that might alter the actions of another medicine taken with it, or that might be unsuitable for other reasons. Patients should read the patient-information lea?et, and seek the pharmacist’s advice if they have any doubt about the information. They should tell their pharmacist or doctor if the medicine results in any unexpected effects.
Potentially dangerous drugs are preparations referred to under the Misuse of Drugs Act 1971 and subsequent regulations approved in 1985. Described as CONTROLLED DRUGS, these include such preparations as COCAINE, MORPHINE, DIAMORPHINE, LSD (see LYSERGIC ACID
DIETHYLAMIDE (LSD)), PETHIDINE HYDROCHLORIDE, AMPHETAMINES, BARBITURATES and most BENZODIAZEPINES.
Naming of drugs A European Community Directive (92/27/EEC) requires the use of the Recommended International Non-proprietary Name (rINN) for medicinal substances. For most of these the British Approved Name (BAN) and rINN were identical; where the two were di?erent, the BAN has been modi?ed in line with the rINN. Doctors and other authorised subscribers are advised to write titles of drugs and preparations in full because uno?cial abbreviations may be misinterpreted. Where a drug or preparation has a non-proprietary (generic) title, this should be used in prescribing unless there is a genuine problem over the bioavailability properties of a proprietary drug and its generic equivalent.
Where proprietary – commercially registered
– names exist, they may in general be used only for products supplied by the trademark owners. Countries outside the European Union have their own regulations for the naming of medicines.
Methods of administration The ways in which drugs are given are increasingly ingenious. Most are still given by mouth; some oral preparations (‘slow release’ or ‘controlled release’ preparations) are designed to release their contents slowly into the gut, to maintain the action of the drug.
Buccal preparations are allowed to dissolve in the mouth, and sublingual ones are dissolved under the tongue. The other end of the gastrointestinal tract can also absorb drugs: suppositories inserted in the rectum can be used for their local actions – for example, as laxatives – or to allow absorption when taking the drug by mouth is di?cult or impossible – for example, during a convulsion, or when vomiting.
Small amounts of drug can be absorbed through the intact skin, and for very potent drugs like OESTROGENS (female sex hormones) or the anti-anginal drug GLYCERYL TRINITRATE, a drug-releasing ‘patch’ can be used. Drugs can be inhaled into the lungs as a ?ne powder to treat or prevent ASTHMA attacks. They can also be dispersed (‘nebulised’) as a ?ne mist which can be administered with compressed air or oxygen. Spraying a drug into the nostril, so that it can be absorbed through the lining of the nose into the bloodstream, can avoid destruction of the drug in the stomach. This route is used for a small number of drugs like antidiuretic hormone (see VASOPRESSIN).
Injection remains an important route of administering drugs both locally (for example, into joints or into the eyeball), and into the bloodstream. For this latter purpose, drugs can be given under the skin – that is, subcutaneously (s.c. – also called hypodermic injection); into muscle – intramuscularly (i.m.); or into a vein – intravenously (i.v.). Oily or crystalline preparations of drugs injected subcutaneously form a ‘depot’ from which they are absorbed only slowly into the blood. The action of drugs such as TESTOSTERONE and INSULIN can be prolonged by using such preparations, which also allow contraceptive ‘implants’ that work for some months (see CONTRACEPTION).... medicines
Hypovolaemic shock is due to a decrease in the volume of blood, as occurs after internal or external *haemorrhage, burns, dehydration, or severe vomiting or diarrhoea. Cardiogenic shock results from reduced activity of the heart, as in coronary thrombosis, myocardial infarction, or pulmonary embolism. Shock may also be due to widespread dilatation of the blood vessels so that there is insufficient blood to fill them. This is the case in severe *sepsis (septic, bacteraemic, or toxic shock), with a resultant systemic inflammatory response associated with *disseminated intravascular coagulation and multiple organ failure. Vasodilatation may also be caused by a severe allergic reaction (anaphylactic shock: see anaphylaxis), overdosage with such drugs as opioids or barbiturates, or the emotional shock due to a personal tragedy or disaster (neurogenic shock). Sometimes shock may result from a combination of any of these causes, as in *peritonitis. The treatment of shock is determined by the cause.... shock