Auditory hallucinations

Auditory hallucinations or auditory verbal hallucinations are a psychological phenomenon relating to the experience of hearing voices. Auditory hallucinations is, although not always, a sign of mental disorders such as schizophrenia or schizophrenia spectrum disorders ¹. However, “healthy” population also report auditory hallucinations to a surprising extent ². Primary psychotic disorder is generally synonymous with auditory hallucinations, whereas psychosis associated with medical/neurologic conditions usually correlates with all other types of hallucinations except auditory (e.g., visual, tactile, olfactory) ¹. Auditory hallucinations can be treated with medication to some degree.

Auditory hallucinations or hearing voices may also happen as a result of the following:

• Being drunk or high, or coming down from such drugs like marijuana, LSD, cocaine (including crack), PCP, amphetamines, heroin, ketamine, and alcohol
• Delirium or dementia (visual hallucinations are most common)
• Epilepsy that involves a part of the brain called the temporal lobe (odor hallucinations are most common)
• Fever, especially in children and the older people
• Narcolepsy (disorder that causes a person to fall into periods of deep sleep)
• Mental disorders, such as schizophrenia and psychotic depression
• Sensory problem, such as blindness or deafness
• Severe illness, including liver failure, kidney failure, HIV/AIDS, and brain cancer
• Severe emotional stress
• Certain physical illnesses. Examples may include migraines, seizures, infections, a very high fever, and problems with the thyroid or adrenal glands.
• Adverse effects of medication. The use of certain medications, such as steroids or pain medicine, can cause hallucinations under rare circumstances. Many other medications can also lead to hallucinations when used in higher doses than prescribed or recommended. Illegal drugs such as alcohol, marijuana, amphetamines, cocaine, and LSD are a frequent cause of hallucinations.
• Nonpsychotic psychiatric illnesses. People who hear voices telling them to do bad things often have behavior problems. Voices that refer to suicide or dying may occur in people who are depressed. The content of a hallucination may help us understand what type of illness a person is having.
• Psychotic illnesses. This includes schizophrenia, major depressive disorder with psychotic features, and bipolar disorder with psychotic features. In addition to hallucinations, psychotic illnesses are characterized by delusions, disorganized and/or bizarre behavior, and moods that don’t correspond with what is going on in someone’s life. Patients may show social withdrawal and inappropriate and unusual use of language. Looking for these symptoms can be very helpful in telling the difference between psychotic and nonpsychotic illnesses.

Auditory hallucinations may accompany severe depression, with voices talking directly to the patient, the content of which is congruent to the patient’s low mood. They may also be seen in manic states, and again congruent with the patient’s mood.

An association between hallucinations and childhood sexual abuse has previously been described ³. Auditory hallucinations have also been reported in post-traumatic stress disorder ⁴.

Auditory hallucinations resulting in self-harm may be seen in patients with borderline personality disorder.

Patients with unilateral and bilateral hearing loss may report auditory hallucinations. Auditory hallucinations may occur in substance-induced psychoses.

Auditory hallucinations are subjective perceptions of external speech in the absence of external stimuli ². Auditory hallucinations are strongly associated with, and the most common symptom in, schizophrenia—usually intrusive, unintentional, unwanted and distressing—with a one month prevalence of about 70% ⁵ and are refractory to pharmacological management in about a third of such patients ⁶. However auditory hallucinations are not diagnostic of schizophrenia and occur in other mental illnesses including borderline personality disorder ⁷, depression, bipolar affective disorders, post-traumatic stress disorder, substance misuse and neuropsychiatric disorders such as dementia, Parkinson’s disease and epilepsy ⁸.

Phenomenologically auditory hallucinations are quite heterogeneous in nature ⁹: varying from first to second to third person commentary; from brief utterances of simple sounds or single words to full conversations; consisting of voices (the average is three) from familiar, personal and repeated to the unknown; from passive discussions to issuing commands; and from pleasant or complimentary to—far more commonly—unpleasant and distressing ¹⁰. Traditional teaching has emphasised the location of the percept in external space, though it is not clear that this is always the case, or that sufferers can clearly so delineate them ¹¹. However auditory hallucinations generally “sound” like “ordinary” voices with definable characteristics such as pitch, volume and accent.

Experimental approaches have generally given less salience to the phenomenological qualitative nature of hallucinations ¹² as opposed to the more quantitative aspects of occurrence, frequency, level of distress, and response to treatment, particularly as part of a broader illness picture. These latter factors can vary considerably between individuals and, following the frequently episodic nature of mental illnesses, for any given individual.

However, auditory hallucinations are not necessarily pathological and it has been accepted that phenomena such as hypnagogic (occurring just before sleep), hypnopompic (on awakening) and bereavement related hallucinatory experiences are within the spectrum of normal experience ². Over recent years there has been a resurgence of interest in the idea of psychotic experiences as lying on a continuum, with non-clinical samples with less intense neutral or positive hallucinatory experiences associated with no functional impact at one end—and hallucinations with greater intensity and negative affect associated with psychotic illness at the other end. In these population based studies, the prevalence of auditory hallucinations varies significantly, with a recent review ¹³ of seventeen studies, suggesting a median prevalence of auditory hallucinations in the healthy population of 13.2% with an interquartile range of 3.1%–19.5%. However the very wide range means that the results of some work, particularly cross-sectional studies and those comprising selective populations, may skew the prevalence results. A recent methodologically robust (n = 7075) longitudinal epidemiological study NEMESIS-1 ¹⁴ that followed up a stratified sample of 18–64 year olds over three years produced far more conservative figures: 7.8% describing hallucinatory experiences (in any sensory modality) on initial sampling; 2.7% at year 1 follow-up; and 2.0% at year 3 follow-up. Another study from the Netherlands estimated that over 10% of population experience auditory hallucinations on a recurring basis ¹⁵, but the fact that 71% of this cohort did not have purely negative content voices (and 91% reported no disruption to their everyday life from the voices) raises an interesting point about participants’ understanding or concept of what “voices” actually mean to the individuals concerned. Distress about auditory hallucinations has been shown to be proportionate to the belief in the voice(s), rather than what it/they say, and the lack of control over their occurrence ¹⁶. Other factors need to be considered when contextualising auditory hallucinations frequency. Stress and tiredness appear to be common precipitating factors for auditory hallucinations, whether with background mental illness or not ¹⁷. There are significant gender ¹⁸ ethnic and cultural variations ¹⁹ in such phenomena, likely reflecting differences of explanation of inner psychic phenomena, acceptability and stigma that will further bias reporting ¹³. In summary, the prevalence of auditory hallucinations in general population samples requires caution in interpretation and awareness that many factors influence the data—including study methods and representativeness of samples, perceived stigma, ethnographic and individual constructs of what “voices” are or mean, and variation in phenomenological strength or severity (and study cut-off threshold) of such symptoms.

When auditory hallucinations have significant impact on daily functioning, several efficacious treatments can be attempted such as antipsychotic medication, brain stimulation and cognitive-behavioural therapy (CBT) ²⁰.

Auditory hallucinations causes

There are many causes of auditory hallucinations, including:

• Being drunk or high, or coming down from such drugs like marijuana, LSD, cocaine (including crack), PCP, amphetamines, heroin, ketamine, and alcohol
• Delirium or dementia (visual hallucinations are most common)
• Epilepsy that involves a part of the brain called the temporal lobe (odor hallucinations are most common)
• Fever, especially in children and the older people
• Narcolepsy (disorder that causes a person to fall into periods of deep sleep)
• Mental disorders, such as schizophrenia and psychotic depression
• Sensory problem, such as blindness or deafness
• Severe illness, including liver failure, kidney failure, HIV/AIDS, and brain cancer
• Severe emotional stress
• Certain physical illnesses. Examples may include migraines, seizures, infections, a very high fever, and problems with the thyroid or adrenal glands.
• Adverse effects of medication. The use of certain medications, such as steroids or pain medicine, can cause hallucinations under rare circumstances. Many other medications can also lead to hallucinations when used in higher doses than prescribed or recommended. Illegal drugs such as alcohol, marijuana, amphetamines, cocaine, and LSD are a frequent cause of hallucinations.
• Nonpsychotic psychiatric illnesses. People who hear voices telling them to do bad things often have behavior problems. Voices that refer to suicide or dying may occur in people who are depressed. The content of a hallucination may help us understand what type of illness a person is having.
• Psychotic illnesses. This includes schizophrenia, major depressive disorder with psychotic features, and bipolar disorder with psychotic features. In addition to hallucinations, psychotic illnesses are characterized by delusions, disorganized and/or bizarre behavior, and moods that don’t correspond with what is going on in someone’s life. Patients may show social withdrawal and inappropriate and unusual use of language. Looking for these symptoms can be very helpful in telling the difference between psychotic and nonpsychotic illnesses.

Auditory hallucinations are strongly associated with and the most common symptom in schizophrenia—usually intrusive, unintentional, unwanted and distressing—with a one month prevalence of about 70% ⁵ and are refractory to pharmacological management in about a third of such patients ⁶. However auditory hallucinations are not diagnostic of schizophrenia and occur in other mental illnesses including borderline personality disorder ⁷, depression, bipolar affective disorders, post-traumatic stress disorder, substance misuse and neuropsychiatric disorders such as dementia, Parkinson’s disease and epilepsy ⁸.

Auditory hallucinations may accompany severe depression, with voices talking directly to the patient, the content of which is congruent to the patient’s low mood. They may also be seen in manic states, and again congruent with the patient’s mood.

An association between hallucinations and childhood sexual abuse has previously been described ³. Auditory hallucinations have also been reported in post-traumatic stress disorder ⁴.

Auditory hallucinations resulting in self-harm may be seen in patients with borderline personality disorder.

Patients with unilateral and bilateral hearing loss may report auditory hallucinations. Auditory hallucinations may occur in substance-induced psychoses.

Auditory hallucinations diagnosis

In patients presenting with hallucinations, a thorough history and neurological examination are required to assess the underlying cause and determine the prognosis. Your doctor will do a physical examination and take a medical history. They will also ask you questions about your auditory hallucinations. For example, how long the auditory hallucinations have been happening, when they occur, or whether you have been taking medicines or using alcohol or illegal drugs. Your doctor may take a blood sample for testing.

Auditory hallucinations are the most common type overall, but in brain disorders, visual hallucinations are the most common.

It is important to assess the modality of the hallucinations and any associated factors. Assess any risk to the patient as a result of them – for example, ask about the nature of the hallucinations and if the patient is frightened of them.

This is particularly relevant if psychosis is suspected because there may be a risk of self-harm, including suicide.

Schneider’s first-rank symptoms of schizophrenia consist of auditory hallucinations where there is thought echo and a running commentary discussing the patient in the third person.

Subclinical hallucinations may be seen in children and occur more frequently in those with conduct and/or emotional disorders.

Auditory hallucinations treatment

Treatment depends on the underlying cause of your auditory hallucinations. Hallucinations may respond to antipsychotic medications. When auditory hallucinations have significant impact on daily functioning, several efficacious treatments can be attempted such as antipsychotic medication, brain stimulation and cognitive-behavioural therapy (CBT) ²⁰. If auditory hallucinations persist, cognitive behaviour therapy (CBT) and supportive psychotherapy may be useful.

The management of a psychotic patient varies greatly depending on the origins of the psychosis. Antipsychotic medications are the gold-standard treatment for psychotic episodes and disorders, and the choice, dosing, and administration of the medication will largely depend on the scenario.

Antipsychotics are generally the treatment for schizophrenia spectrum disorders. Initial dosing should be at a low dose and titrated up as needed. Of note, there has been long-standing debate as to whether second-generation antipsychotics are more efficacious than the first generation ²¹.

Antipsychotics have also been shown to be most effective in treating the psychotic symptoms of drug-induced psychosis, mania, delirium ²², the psychotic features of depression, as well as the psychotic features of dementia and other neurologic conditions. Of course, beyond the acute psychosis, treating the underlying cause is always an appropriate course of action.

Antipsychotic medications have demonstrated to be most effective in positive symptoms of psychosis (hallucinations, delusions, disorganized thoughts, and behavior) and less useful for negative symptoms ²³. They can also demonstrate significant side effects, including extrapyramidal symptoms and dangerous QT prolongation. Of note, clozapine and olanzapine specifically have been shown to reduce the risk of suicide in psychotic patients ²⁴.

Benzodiazepines have evidence as an effective treatment for catatonic symptoms of psychosis.

Along with medications, family and caregivers also play an important role in the management of a psychotic patient, including providing a safe and therapeutic environment for the patient, as well as interacting with them in and calm, empathetic manner ²⁵.

In the scenario of an agitated, potentially aggressive, acutely psychotic patient at risk of harming themselves or someone else, they should be hospitalized and placed in the care of health care professionals. An injectable form of a typical antipsychotic with a benzodiazepine is most effective in this case ²⁶. Physical restraints should be avoided at all costs and correlate with increased mortality.

Along with medications, cognitive behavioral therapy can play an integral role in the treatment of patients with psychotic symptoms ²⁷.

Lastly, it is critical to note that for acute onset psychosis in patients, ultimately developing a schizophrenia-spectrum psychotic disorder, early intervention may improve clinical outcomes. Delays in treatment have statistical links with poorer treatment outcomes ²⁸.

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