H. Ey (1973), in his vast Treaty hallucinations hallucination defined by a perception without object to be perceived.Hallucination is both a diversion of perception and a challenge to reason. Its development is often based on a deterioration of the sensory message and an overflowing imagination.

Nevertheless, the lack of critical characterizes hallucinatory behavior.

Real for the subject, unreal for the observer, the hallucination is inherently a source of misunderstanding and also convinced of the reality of what he perceived, the patient fears the judgment of the observer. A hallucination is a sensory phenomenon of nature fleeting or permanent, internal to the individual, sometimes from the abnormal functioning of one or more senses, sometimes due to a confusion of the mind or the revival of a mental image .

In most cases, the hallucinations are part of a psychiatric or neurological disease. Because of their subjective nature, their description depends, of course, the premorbid personality of patients. Hallucinations can involve all the senses and are sometimes associated with each other and every possible way.


Auditory hallucinations:

What we can learn auditory hallucinations depends on the contact established with the patient and confidences he would have us do. Indeed, we belong to a culture that has long been “hearing voices” is “be crazy”. In some cases, such hallucinatory, although they remain very reluctant, express their status despite themselves by listening attitudes, or by using various tricks to preserve their voice, with varying efficiency , the most common being the use of objects to block the external auditory canals (the walkman has now replaced the cotton in the ears).

Auditory hallucinations are almost always present in acute delirious episodes, they are common in chronic delusional psychosis (schizophrenia, paranoid schizophrenia, paraphrenia), but can also occur in the delirious forms of mania or melancholy. In the latter case, they repeat the themes of autoaccusations and indignity, and may make orders of suicide, often executed, etc.

Auditory hallucinations are the most common sensory hallucinations.

They can be simple or complex.

Simple auditory hallucinations:

Simple hallucinations are characterized by type sound “hiss” of “bells noise” or “flowing water”. They are usually epileptic origin.

Psycho verbal hallucinations:

The psycho verbal hallucinations are a subset of the auditory hallucinations that concern language.

In psychiatry, hallucinations are often acousticoverbales. The patient hears individual words, sometimes still the same, sometimes changing, but above phrases, voice, localized in space, speaking them, addressing him or designating third person.

Sometimes he seems to capture a conversation not intended for him, or about the dialogue with his voice. The speakers can be identified or not, known or unknown, whether through voice characteristics or intuitively. These voices can speak in the native language of the patient, but sometimes in a foreign language, known or unknown to them. The content is often hostile, abusive, threatening, but it can also be flattering and friendly, and in some cases, the positive and the negative alternate. Or the voice repeated the thought echoed communicating delusional information. In some cases, it is hallucinatory orders, which patients are not always able to resist.

But whatever these varieties, it is psycho hallucinations if the words are perceived as coming from outside, from outside the body through the ears, and associated with irrefutable belief in their reality.

They can come from near and far, clear or difficult to read, go through one ear or both. Sometimes explanations can organize around these voices: hidden microphones, remote shares, wireless telephony, etc., to complex delusional elaborations. These hallucinations occur with widely varying emotional impact, sometimes indifferent, sometimes with irony, often indignantly.

Visual hallucinations:

It also distinguishes the simple visual hallucinations (or elementary) complex (or developed). Visual hallucinations can be stationary, moving, kaleidoscopic, of normal size, lilliputian, gullivériennes, macroscopic, microscopic, appearing in perspective in space or coated on the surface of objects. They can be opaque or transparent, more or less, achromic or colored, neutral emotional tone, euphoric or elated. Vigilance may be normal or decreased. They can occur in the light, in the dark or eyelid closure, but always independently of any external visual stimulation. Moreover, sensory deprivation or extended stay in the dark leads to simple or complex visual hallucinations.

There are frequent entanglement with perceptual illusions and the dream state.

Simple visual hallucinations:

Their description is always metaphorical ( “as if”). It is ephemeral events, but may be repeated: light flashes (photopsia), flames, flashes, flashes, colors,

bright points (phosphenes), lines, stars, floating things in space or geometric shapes.

But it never is clearly identified objects. Their starting point may be on the entire optical path. These elements can fill the entire field of vision, or limited to a half-field, or concern only one eye. They may maintain or remove the closure of one or both eyes.

The subject knows that there is no real object before him, but he can not deny that he saw.

The original single visual hallucinations are multiple and varied pressure eyeballs in a normal subject, ophthalmic migraine (most frequent origin, preceded for about ten minutes of a scintillating scotoma, but criticized by the patient), glaucoma, diseases of the retina, macular degeneration, poisoning (amphetamines, mescaline, cannabis, etc.), drug detoxification, sleep deprivation, fasting, vitamin deficiencies, hyperthermia, hypoxia, will have an epileptic attack (FLE), occipital lesions ( hallucination in the visual field deficit).

Complex visual hallucinations:

They are highly variable: perception of objects, characters, animals, landscapes or complicated and indescribable scenes, they occupy the entire field. The aesthetic visual hallucinations are culturally specific purposes, with shape, color and very concrete aspects. This is a new experience and not a recall. The vigilance level is normal, and the belief is quite variable, although the subject vivid experience as undoubtedly perceptive.

The report of the hallucinatory object to the rest of the field is homogeneous (for example, if it is a hallucinatory cat, it may be lying on the couch real). The distinction between sensory hallucination and illusion is often tricky.

Complex visual hallucinations have a disparate etiologic significance: temporal lesions or temporo-occipital, temporal lobe epilepsy or parietooccipital (but hallucinations criticized), poisoning or alcohol withdrawal (zoopsies delirium tremens), sepsis hyperpyretic, hallucinatory drugs (they can then occur at distances of poisoning), ophthalmic diseases (stem or dreamlike hallucination Vesper elderly subjects, atherosclerotic and hypertensive). They are relatively rare in chronic delusions and schizophrenia and are most noticeable in confusooniriques states and sometimes in secondary states hysterical (religious figures visions, for example).

Tactile hallucinations (or haptic):

They concern the area of skin sensitivity, that is to say the touch. In elementary forms, the subject feels limited or diffuse, continuous or discontinuous, skin impressions: hot, cold, humidity, pressure, itching, bites, burns, etc. These impressions come from any external phenomenon determined.

When tactile hallucinations developed, the patient recognizes a good hot or cold water jet, contact with one hand (invisible), parasites (parasitic hallucinatory) or links, or son seams of iron surrounding the body , etc. These hallucinations can remain isolated or participate in a delirious development more or less organized. It can then be a topic of influence, where one often finds verbal and genital hallucinations, or a hypochondriac theme. They are also seen in poisoning with cocaine (discontinuous hallucinations) or chloral (continuous hallucinations).

Gustatory hallucinations:

Affecting the taste, they can take very different aspects. It is often perceptual illusions, clarified afterwards. The subject has been drinking a liquid or eating a food and the moment he realized nothing, or simply felt a strange or bad taste in the mouth, but he did not understand the meaning. Later, he realized it was a poison, sometimes due to secondary digestive disorders. Most often, these experiments fall into delirium dominated by themes of poisoning, and where can associate a refusal to eat. Sometimes they occur before an epileptic attack.

Olfactory hallucinations:

It is experiences where the smell is felt as such, sweet, nauseating or indifferent, but not assigned to a specific object, or experiences where this item appears definite. This is very often of body odor, with sexual or scatological connotations, or hallucinations integrating into delusions of persecution by the gas ( “they send me smells through the walls of my house” ). There is also a special variety which the subject to feel emit an unpleasant odor, he feels himself and he thinks others should feel it too. This can range from simple phobia of its own body odor until delusional or melancholic aspects.

Coenesthésiques tangible and hallucinations:

They concern the general and internal sensitivity.

This area concerns both neurology psychiatry.

The asomatognosies are characterized by the lack of knowledge of a part or the whole body, without impairment of sensitivity. These are patients with left hemiplegia (in right-handed) and ignore both this hemiplegia and membership on the left to their own bodies. The view corrects anything.

Two varieties exist:

– Anosognosia in which predominates ignorance of the palsy;

– Anosodiaphoria characterized by indifference to the patient’s condition.

This asomatognosia persists when hemiplegia improves. There are also bilateral asomatognosies, most famously J. Gerstmann’s syndrome (1924): inability to name fingers on the subject and the observer, with right-left confusion and Alexia. We can compare these bilateral but partial alterations in body image more comprehensive alterations found in the delirium of negation of Cotard.

Also in this class some hallucinations related to deafferentation.

depersonalisation syndrome, meanwhile, combines impressions of bodily transformations of electrical injuries, metamorphosis of the body, or a perception of diabolical possession or zoopathique body.

Sexual or genital hallucinations:

Hallucinations of the sexual sphere are often associated with verbal hallucinations. This is the undoubted inner feel coerced sex by a partner or distant, unidentified or unknown, single or multiple. These reports are usually rejected with indignation and disgust, though this refusal not enough to make them stop. Sometimes the patient can accept and even find enjoyment. It can be ordinary sexual relations, orgasm sensation, touching, sodomy or rape distance.

The patients can then make ridiculous defenses: occlusion natural cavities, protective belt, etc. These hallucinations can be only very few themed, but they often participate in a delirious development of up to an influential syndrome, with all sorts of details on how and actors.


Also called pseudo-hallucinations, hallucinations or false apperceptive hallucinations, they are characterized by the absence of sensory component. They are experienced only in the imagination or thought of the subject, experienced as strange or foreign psychic phenomena. It may be pure thought, without externalization or acousticoverbales psychic hallucinations.

The Terror hears his thoughts as if they were from another, or hears of soul to soul conversations, secret or inner voices, quietly, experiencing thought transmissions or purely mental perceptions.

It can also act psychic visual hallucinations involuntary mental images, fantasy scenes, inner visions, etc.

This type of psychic hallucinations observed in chronic delusions.

The mental automatism syndrome, described by G. Clérambault, is a set of signs with no external projection, signs that are pure thought and phenomena which represent the conscious level, no meaning. Some speak of the loss of private property of thinking, because the patient comes to no longer be safe to remain in control of his own thought.These parasites sensations of sudden onset. The main signs are: taking flight or thought by others, guessing the thoughts of others by himself, duplication of thought, a sequence of memories, echoes the thought, reading or writing, stating the actions, intentions and acts the comment.


Psychiatric disorders:

Hallucinations are the basic mechanisms of delirium and occupy a central place in the classification of psychoses.They can also occur as part of a hysterical neurosis.

Some subjects do not entrust their hallucinatory experiences, for various reasons, and we must know the search.

Acute psychoses:

Acute delirious puff:

It can cause delirium polymorphic in its themes and mechanisms of sudden onset, rapid incorporation and kaleidoscopic organization, that is to say having fluctuations in kind and intensity. Hallucinations are common and varied.

Delirious melancholy:

A hallucinatory form of melancholy is classically described. The melancholic delirium is powered by visual or auditory hallucinations, congruent with the depressive themes.

They would be the expression of a projected guilt.

Delirious mania:

Delusional experiences of these states can be hallucinatory. But the presence of hallucinations in a manic episode did discuss the possibility of an organic or toxic factor associated.

Chronic dissociative psychosis: schizophrenia:

Hallucinations and / or mental automatism are common in schizophrenia, particularly in its paranoid form. The most common are auditory hallucinations.

It is estimated that hallucinations occur in 60-70% of patients with schizophrenia (600 000 patients in France). This is a major handicap source that can lead to rapid socio-professional disinsertion, sometimes lasting. In 25% of cases, the hallucinations become resistant to pharmacological treatments and chronicisent.

In such cases, the alteration of the quality of life of patients can cause a risk of suicide.

Paranoid schizophrenia:

This is a French clinical entity within the group of chronic psychoses non dissociative (as opposed to schizophrenia, dissociative chronic psychosis). It is characterized by acute or progressive late onset, a slow evolutionary potential and a multi-hallucinatory symptoms: hallucinatory manifestations association particularly pervasively present and a great mental automatism.

Hallucinations are observed in all sensory areas, with hearing prevalence (frequency of insults), olfactory (odors prevalent in the home) and cenesthetic (genital, electric current in the body, etc.). The theme of the delusion is often persecutory and frequently organized in the vicinity. It is also responsible for running away or iterative moves.

The evolving risks are acting out various, reaction depression, refused care and social withdrawal or institutional dependence.

Neurological pathologies:

Hallucinations related to deafferentation:

Suppression or distortion of the message related to a sensory channel does not necessarily abolish the perception, but releases the mental image of the control normally exercised by the real world. Perceptions of ophtalmopathes pointless and those of otopathes bring in the demonstration as well as the phantom limb amputees. Thus, visual hallucinations may occur in blind and auditory hallucinations in deaf when deafness and blindness are acquired. These hallucinations must be systematically sought, because they are rarely mentioned spontaneously, patients with fear of being “crazy” or feel that it does not concern their doctor (see Bonnet Syndrome).

Normally these avatars of perception does not result in conviction, except when degradation judgment of reality intervenes.

Such degradation can take an overall failure of the intellectual functions, such as mental confusion or dementia.

It can also be the result of an elective deterioration of the judgment insofar as it relates to body image and perception of space, as observed in patients with lesions of the hemisphere law.

The illusion or hallucination of amputees ‘phantom limb’, described by Ambroise Paré, is the most common form and the most spectacular bodily hallucinations by deafferentation.

These amputees still feel they have lost their limb segment.

This disorder is very common because it affects about 80% of amputees. The treatment of the perception of a phantom limb is justified only in the minority of cases where the hallucination is accompanied by debilitating phantom pain.

One of the difficulties of treatment is linked to physiopathogenic uncertainties of this disorder.

The cutaneous electrical nerve stimulation or continuous brachial plexus blocks anesthetics are used. Most frequently used are benzodiazepines, carbamazepine, anesthetics systemically, opioids, or serotonergic antidepressants.

very similar bodily hallucinations can be observed outside of amputations in lesions of nerve plexus nerve root, spinal cord and brain.

Hallucinations, epilepsy and migraines:

Paroxysmal hallucinations are frequent in epileptic and migraine attacks.

They are most often associated with other symptoms and to assign them to a seizure or migraine, the precise description of these hallucinations, their progress and any associated symptoms are often the key to diagnosis.Semiotics of these hallucinations is particularly rich, can affect all sensory and psychic terms.

Epileptic hallucinations are usually short and last from 5 to 120 seconds, whereas migraine auras last rule in more than 3 minutes but rarely extend beyond one hour. Typically, migraine auras appear several minutes before the headache and disappear as soon as it occurs.

While epilepsy visual hallucinations are often colored with a circular or spherical path, always begin the same side and are not associated with photophobia, migraine auras are usually black and white, have a ride online or zigzag, the center of the visual field moving towards the periphery, often leaving a central scotoma, and are often followed by photophobia.

The Alice in Wonderland syndrome reflects the semiotic richness of certain migraine attacks. Patients describe a distorted image of their body, which is usually not followed by a migraine headache and therefore the only symptom of the migraine attack. Some authors have suggested that Lewis Carroll described in his book his own migraines.

Although seizures and migraine attacks fall into two distinct processes, they have some common clinical manifestations that sometimes make their diagnosis difficult. During a migraine aura, with or without headache, visual symptoms are almost constant (diplopia, halo around objects, discoloration, visuospatial disorder, darkness, micro and / or macroscopic, Palinopsia (perseveration of perception after the object was removed from the field, metamorphopsia, etc.). Some unpleasant olfactory hallucinations associated with these events have even been described as the initial symptom of a migraine attack.

Hallucinations, dementia and neurodegenerative diseases:

The hallucinations occurred during senescence is not the same value or semiotic nosographic as described in younger patients.

Parkinsonism four treaties develops hallucinations. The influence of DOPA and that of all the dopaminergic medications are not directly related to the dose. Although it is now established that the hallucinations of Parkinson have a relationship with a dysregulation of sleep, they are distinguished hypnagogic hallucinations. In treated patients, the proliferation of hallucinations is associated with cognitive impairment, confusion or dementia.

Thus, they are also common in the Lewy body disease where Parkinson’s pathology attributable to extend the neurons in the cortex. The incidence of hallucinations in other forms of dementia is less well established: absent in subcortical dementias (Huntington’s disease, Steele Richardson’s disease), rare in frontotemporal dementias, they would be more frequent in the disease Alzheimer.

Hallucinations in these degenerative diseases require treatment when, not evil or criticized, they are accompanied by significant anxiety and / or behavioral disorders.

In all cases, a reduction in treatment may induce or encourage the appearance of hallucinations is desirable where possible (anti-Parkinson, anticholinergics). Sometimes the addition of a non-hallucinatory treatment is necessary.Conventional neuroleptics are cons-indicated in Parkinson’s disease and dementia with Lewy bodies, because of the risk of worsening of motor disorders. In Alzheimer’s disease, treatment of hallucinations and delusions classically based on haloperidol. The new generation of antipsychotics have been many studies in Parkinson’s disease, but only the low dose clozapine (less than 50 mg daily) has demonstrated its effectiveness. This medicine does not worsen parkinsonism and may even improve tremor. Strict strict blood monitoring is required because of the risk of agranulocytosis.


Many substances can cause hallucinations, a dreamlike and psycho illusions. LSD and mescaline are the prototypes of hallucinogenic drugs. Cannabis, amphetamines, ecstasy, opiates and certain fungi can also lead to hallucinations.This is most often visual hallucinations or delusions, simple or elaborate. In some subjects, the hallucinogen intake may precipitate or trigger chronic psychotic states.

As hallucinogenic drugs, many drugs can trigger hallucinations by their interference with neuromédiation devices.Neuroleptics erase these hallucinations as they erase psychotic hallucinations.

Just as alcohol withdrawal, benzodiazepine withdrawal is currently one of the most common causes hallucinations and confuso-dream states. Drug-induced hallucinations of any type, can occur at usual doses or overdose, in single or continuous processing.

The therapeutic approach is to reduce the dosage of the offending drug, or even stop if symptoms do not improve.

Preventive treatment is to identify patients potentially at risk according to different criteria: a history of hallucinations for the molecule or molecules of the same mechanism of action, or any other molecule, higher age, organic brain damage, hallucinations history.

Anti-hallucinatory drugs:

The most used are neuroleptic or antipsychotic first or second generation.

be mentioned in particular haloperidol (Haldol, 5 to 20 mg), amisulpiride (Solian®, 400-1 200 mg), risperidone (Risperdal, 2 to 8 mg) and olanzapine (Zyprexa®, 10 to 20 mg).

Neuroleptics have no effect on the hallucinations associated with deafferentation, those dependent of a sleep disorder or occurring during a withdrawal state.



According Lasegue “hallucinations differ from illusions as slander differs from gossip.” Hallucinations and delusions differ by the presence or absence of criticism.

The illusion is an erroneous perception of the real world in which the identification is correct, and it is still criticized by the subject. Thus, the opposition established by Esquirol between delusions and hallucinations is justified since patients readily relate these phenomena to a disorder of perception. Nevertheless, the distinction is sometimes difficult and transitions are frequent, especially when a real object before changes extend into a hallucinatory image. The malfunction or deprivation of sensory apparatus that gives rise to the illusion promotes hallucination.

Illusions can touch all the senses.

The auditory illusions are, for example unclear taken for noise words. When optical illusions, perceived objects are altered in various ways: the picture may change size, position, shape, color, or light rays are interpreted as a halo of God, etc.


French term for a type of hallucinatory phenomenon but criticized by the patient. There is no adhesion of the subject, not of conviction and certainty as in hallucinations. The hallucinatory phenomenon is sometimes experienced as fun, other times very anxiety-provoking or even terrifying. The hallucinoses appear at the end of day, twilight period ending in seconds or minutes, they recur in the night and breed for weeks or months.

The patient perceives animals, human figures and often colorful mobile visions disappear eye opening. Patients often believe in their reality during the episode, but secondarily admit their unreality. The causes are primarily a vascular disease of the upper brain stem, occipital or temporal lesions and ophthalmopathy (Charles Bonnet syndrome), sometimes poisoning or encephalitis.

Hallucinosis are a neurological symptom having a value of precise location.

The hallucinose stem is the most representative example. These are subjects which in the dark, but away from falling asleep, see enter their room small animals and small characters that move quietly and disappear when trying to reach.These hallucinations can be much more elaborate, but the patient remains convinced of the unreality of the facts.


The dreamlike (or metamorphopsia) combines the hallucinations experienced a dreamlike state and loss of space-time references causing confusion. It is therefore a global alteration of perceptual experience, dominated by delusions and visual hallucinations, colorful and lively. Combine it an important suggestibility, a decision of the subject in the hallucinatory action in which it is located, with rich hallucinations, projected into space, representative, integrated into the outside world.

The belief of the subject is complete. The fantasy is often terrifying scenes is common in toxic delirium.

At maximum, the fantasy becomes confusoonirique delirium, delusional and hallucinatory experience confusional states. It comprises a succession of visual hallucinations, mobile discontinuous images, kaleidoscopic, chaotic, with different themes: erotic, mystical, professionals, and sometimes associated with tactile hallucinations. The confused completely adheres to his delirium, which is true hallucinatory and delusional belief that may persist.


They are wrong judgment or intuition on a real perception. For example, the subject actually hear the crowd: “This is an unanswerable question,” but he thinks this sentence speaks for itself and means that his enemies are seeking to get rid of him. In another case, a subject that sniffs a city gas smell, or feel nauseous, deduces that his persecutors seek to poison him. Or a light that illuminates the face tonight means a lover waved to the wife.

However, it is sometimes difficult to distinguish precisely, especially in delusions of persecution, the delirious intuitions, illusions, misperceptions and delusional interpretations.


These are subjects which mostly by interest related hallucinations they never had. This is often in the context of criminal expertise. But mostly, the clinician does not take it.

Hypnagogic imagery and hypnopompic:

The difference between dream and hallucination is that sleep separates the sleeping real world: it ceases to perceive, he is deprived of the means to act. Mental imagery of dreams develops in an abstract space, unrelated to the real world. This imagery predominates during REM sleep which the polygraph route is characteristic. These phases involve a particular device, the system tips Ponto-géniculo-occipital.

This mechanism can escape the control exercised over him the device that governs sleep, so that, when falling asleep (hypnagogic hallucinations) or upon awakening (hypnopompic hallucinations), mental imagery can surprise a subject yet normal or already awake. Moreover, narcoleptic subjects plagued by REM sleep onset may lead, during the day to brief hallucinatory episodes can be extremely lively.

They are colorful scenes, script without images, which appear closed eyes, which last a few seconds or minutent and disappear eye opening or exercise. They do not have a scary character.


The subject lives experience overall perceptual alterations, or daydream, or sudden intuition that the whole atmosphere seems strange, suspicious, worrying, with a diffuse threat, impossible to define or déjà vu, where the subject s’ realizes that he has already experienced the situation in which he is and he knows what’s going to happen, but with an uneasy feeling. In these cases, the level of vigilance is always changed.


Complex in its mechanism, different in content and meaning that the patient gives him the hallucinatory phenomenon has multiple causes.

Can one be deluded without being insane? Yes.

Any patient who experiences hallucinations, whatever their type, and especially at the beginning, should receive a thorough medical examination and in particular of a specific neurological examination, supplemented by an eye examination, an electroencephalogram (EEG), a scanner cerebral and laboratory tests.

Neurochemistry has shown that a number of molecules (especially serotonin) can determine alterations in humans lived experience such as perceptual illusions, metamorphopsia and sensory hallucinations.

Clinical neurology and neurosurgery have established the relationship between sensory or sensory cortical areas and elementary hallucinations, and also between different types of dream state and the temporal lobe. But this provides no explanation as to auditory hallucinations acute or chronic delusions.


The production of a mental image is associated with activation of a challenge constellation denies cortical areas and subcortical formations whose functional imaging techniques have demonstrated specificity.

subjective phenomenon, random and fleeting, hallucination lend itself to such correlations.

However, it is established that its occurrence corresponds to the activation of the association cortex, or even the primary cortex, in the corresponding sensory device.

Off occurs when the hallucination, imaging techniques can detect abnormalities of brain function that predispose to hallucinations. Acousticoverbales the hallucinations of schizophrenics were studied in this light.

Functional imaging showed the influence of

the attention given by the subject to a sensory event that waits and the interference of emotional determinants.

Now it is no longer possible to treat hallucinations without reference to brain dysfunction that governs their occurrence.

The theme of hallucinations often seems linked to the history and memory of the subject.

However, the brain mechanisms promoting the appearance of hallucinations in that subject and not in such and other sensory modality in which they occur can be better understood in the light of recent results of brain imaging. This new information is essential for the development and short-term evaluation of new therapeutic strategies. It could be to assess the pharmacological effects but also some forms of psychotherapy, or to promote the emergence of new therapeutic methods.


The knowledge we have of ourselves and the world is based on the synthesis of information from our sense organs.

Hallucinate, is to deceive oneself about the state of the world or on the state of our body.

The hallucinatory phenomenon, given the great diversity of its terms can not have an unequivocal explanation. Thus, the varied clinical presentations, many circumstances of occurrence and the consequences for the subject and his entourage are hallucinatory phenomena a major field of study.

A good knowledge of hallucinatory manifestations and their peculiarities in acute and chronic psychotic disorder contributes to the diagnosis and guide treatment strategy. Furthermore, the possible relationship between hallucinations and some acting out self or hetero-aggressive is well known acts of delirium confused plagued by terrifying and threatening visual hallucinations, gestures made during acute delirium or by chronic delirious under the influence or dictation auditory hallucinations, or psychomotor automatism.

Recent advances in functional brain imaging and clinical applications may enable rapid progress in this field. The interest will be at least twofold: understanding the neurobiological mechanisms involved and especially ability to test new hypotheses for the development of new active molecules on hallucinations.

Nevertheless, the diagnosis of established hallucinations, he reports a specialized care, whether neurological or psychiatric.