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Auditory hallucinations are the sensory perceptions of hearing noises without an external stimulus. This symptom is particularly associated with schizophrenia and related psychotic disorders but is not specific to them. This activity provides an overview of the current understanding of auditory hallucinations in terms of etiology, pathophysiology, and treatment options, with further explanation of approaches to enhance the interprofessional team's integrity in improving the outcome of individuals with this condition. Objectives: Assess the etiology of auditory hallucinations. Identify the pathophysiology of auditory hallucinations. Differentiate the management options of auditory hallucinations. Summarize the interprofessional team strategies for enhancing care coordination and improving patient outcomes. Access free multiple choice questions on this topic.

Auditory hallucinations, or paracusias, are sensory perceptions of hearing in the absence of an external stimulus. Auditory hallucinations can refer to a plethora of sounds; however, when the hallucinations are voices, they are distinguished as auditory verbal hallucinations. This specific subset of paracusias is particularly associated with schizophrenia but is not specific to it. Nonpsychotic disorders associated with auditory verbal hallucinations are affective, trauma-related, substance-related, and neurological disorders.[1] These voices can be distressful when threatening, derogatory, commanding, or haunting, affecting an individual's social and occupational functioning. Fortunately, paracusias respond well to the administration of psychotropic medications.

Because auditory hallucinations manifest in a variety of disorders, the etiology is thought to be heterogeneous. Hallucinations most often precipitate in the setting of psychosis. Imaging studies using positron emission tomography and functional magnetic resonance imaging of patients with schizophrenia demonstrate increased activity in the striatal and thalamic subcortical nuclei, paralimbic regions, and hypothalamus. Further analysis reveals deficits in left temporal lobe functioning.[2][3] Further consideration has been placed on aberrant glutamatergic transmission, which coincides with the hypo-functioning glutamate receptor hypothesis of psychosis.

The prevalence of auditory hallucinations in the general population ranges from 5% to 28%.[4] Auditory hallucinations are most prevalent in patients who have psychosis.[5] They are observed in 75% of individuals with schizophrenia, 20-50% of individuals with manic depression, 10% of individuals with major depression, and 40% of individuals with PTSD.[6] The prevalence is 9% and 5 to 16% in children and adolescents, respectively.[7][8] It most often manifests in children in the setting of conduct disorder, migraine, and anxiety.[9][10][11] The remission rate of auditory hallucinations in adolescence ranges from 3% to 40% each year.[12]

The precise mechanism by which paracusias occur remains elusive. However, several postulations have been suggested.[13] Functional magnetic resonance imaging findings have demonstrated the spontaneous activation of the auditory network, consisting of the left superior temporal gyrus, transverse temporal gyri (Heschl gyri), and the left temporal lobe.[14][15] A neurocognitive model called the VOICE model has been offered, which attributes the paracusias to an unbalanced bottom-up limbic hyperexcitation mismatched against a hypoactive prefrontal inhibitory system.[16] This mismatch results in the spontaneous firing of sensory neurons without appropriate inhibitory mechanisms. Some data suggest that the thalamus-amygdala pathways are activated, thereby processing an emotional response to the auditory hallucinations, which is further proved by another study detecting choline and N-acetyl aspirate ratio abnormalities in the thalamus.[13][17] At a neurochemical level, dopamine (D2) and serotonin (5HT2a) receptors are particularly important. Neuroimaging studies have demonstrated increased D2 receptor occupancy in the striatal system and 5HT2a receptor occupancy in the caudate nucleus.[18]

Paracusias may be perceived as coming through the ears, on the body's surface, mind, or anywhere in external space. They can occur as frequently as daily or as an isolated episode. The quality of the hallucination is also variable. They can be loud or soft. As mentioned previously, paracusias can be incoherent sounds or distinct voices. Depending on the level of insight the patient maintains, the paracausias can greatly impair. Auditory hallucinations most often manifest in the setting of formal thought disorders; however, they can present in protean settings, as well.[19] When associated with schizophrenia, paracusias vary according to the stage of the illness. In the late prodromal stages, inner speech becomes more objectified and externally perceived.[20]

The evaluation of paracusias consists of a general psychiatric interview that includes details regarding the evolution of the hallucinations, triggering factors, psychiatric review of systems, past psychiatric diagnosis, history of substance use, family history of psychiatric illness, and history of trauma. A detailed medical history and medication regimen, including over-the-counter supplements, should also be obtained. The clinician's most valuable assessment tool is the mental status examination, addressing mood, affect, appearance, behavior, speech, thought content, thought process, insight, and judgment. Furthermore, determination of the presence of 'first-rank' or 'Schneiderian' hallucinations, which are voices speaking to each other or narrating one's thoughts aloud, should be completed. The clinician should determine if the hallucinations are temporally associated with affective disturbances and, if so, if they are congruent with mood. To further assess the patient's safety and the safety of others, the patient should be asked to elaborate on whether the hallucinations command him or her to perform certain acts. Lastly, organic medical etiologies should be ruled out using analysis and neurologic imaging. Laboratory analysis includes: Urine toxicology Complete blood count with differential Vitamin B12 and D levels Renal function test Serum electrolytes Hepatic function test Blood alcohol Computed tomography or magnetic resonance imaging if suspecting organic brain abnormalities Electroencephalogram for a seizure disorder

First, any underlying organic disease should be addressed and treated accordingly. If the organicity acted in the capacity of the inciting precipitant, then the paracusias should ostensibly resolve as the disease dissipates. However, if the hallucinations precipitated as a result of a primary psychiatric disorder, then neuroleptics become the mainstay of treatment. Neuroleptics, colloquially referred to as antipsychotics, are a class of psychotropics that block dopamine receptors. The putative mechanism by which neuroleptics mitigate auditory hallucinations is by blocking dopamine D2 receptors in the mesolimbic tract. The initial subclass of neuroleptics, the first-generation antipsychotics, have a primary mechanism of action that is antagonism of the D2 receptor, whereas the subsequent second-generation antipsychotics (SGA) act more indiscriminately on an expanded array of receptors.[21] Generally, debates about administering first or second-generation antipsychotics are resolved by considering the side effect profiles of the specific medications under consideration.[21]] Independent of the subclass chosen, the perceptual anomalies should abate within a week of the initiation of the psychotropic. Sometimes, these auditory aberrations can persist and require the administration of an additional neuroleptic in conjunction with the first. If the hallucinations continue to demonstrate resistance- following the administration of 2 antipsychotics- the clinician is encouraged to switch to clozapine, an SGA. Clozapine has shown to be the most efficacious antipsychotic for the treatment of positive symptoms of schizophrenia such as delusions, hallucinations, disorganized behavior, and speech; however, it is also associated with the greatest danger as it can induce blood dyscrasias, specifically agranulocytosis. This neuroleptic requires astute clinical monitoring, with weekly and then biweekly blood draws.[21]

Independent of the subclass chosen, the perceptual anomalies should abate within a week of the initiation of the psychotropic. Sometimes, these auditory aberrations can persist and require the administration of an additional neuroleptic in conjunction with the first. If the hallucinations continue to demonstrate resistance- following the administration of 2 antipsychotics- the clinician is encouraged to switch to clozapine, an SGA. Clozapine has shown to be the most efficacious antipsychotic for the treatment of positive symptoms of schizophrenia such as delusions, hallucinations, disorganized behavior, and speech; however, it is also associated with the greatest danger as it can induce blood dyscrasias, specifically agranulocytosis. This neuroleptic requires astute clinical monitoring, with weekly and then biweekly blood draws.[21] If the hallucinations manifest in the setting of affective disorders, such as depression or mania, then corresponding psychotropics should be given adjunctively (eg, antidepressants and mood stabilizers, respectively). Psychotherapy can also be applied in conjunction with pharmacotherapy. The most robustly researched psychotherapeutic modality has been cognitive behavioral therapy (CBT). CBT instructs the patient to modify how he or she experiences the paracusias, ultimately offering an improved sense of control over the hallucination. CBT uses Socratic interviewing rather than confrontation, implements reality testing, and can be provided individually or in groups.[22] Other treatment approaches include ACT (acceptance and commitment therapy), HIT (hallucination-focused integrative treatment), ATT (metacognitive therapy attention training technique), relating therapy, distraction techniques, and HVN (hearing voices network) self-help group, all strategies to cope better with the voices. Several studies have shown efficacy in reducing auditory hallucinations using transcranial magnetic stimulation, but the evidence is still lacking.[23]

To differentiate the causes of auditory hallucinations, it is pertinent to focus on the following: A detailed medical history, laboratory analyses, and neuroimaging are needed to rule out organic etiologies. Details regarding substance use (illicit and over the counter), medication profiles, and supplement use to rule out toxic-metabolic causes.[24][25] Detailed psychiatric family history, as many psychiatric illnesses show high heritability. Manifestations of auditory hallucinations can occur in a multiplicity of psychiatric conditions, including schizophrenia, bipolar disorder, depression, trauma-related disorders, dissociative disorders, personality disorders, and parasomnias.[26] Furthermore, neurological conditions such as tinnitus, cerebral tumors, traumatic brain injury, epilepsy (particularly temporal lobe epilepsy), viral encephalitis, delirium, and cardiovascular events that involve the brainstem regions or areas of temporal, temporoparietal, or occipital pathways can present with auditory hallucinations.[27][28][27] Other organic etiologies include neurodegenerative conditions, conditions that incur damage to the peripheral sensory pathways (eg, acquired deafness, thyroid dysfunction, nutritional deficiencies), chromosomal abnormalities, autoimmune disorders, and acquired immunodeficiencies.[2][29][30][29][31][2][32] Research suggests that auditory hallucinations can also precipitate, transiently, in response to conditions of extreme physiological and psychological stress such as dissociative identity disorder, fatigue, and bereavement.[33]

If the etiology is of an organic nature, the prognosis is contingent upon the underlying disease process. Therefore, the hallucinations should, in theory, resolve as the precipitant resolves. However, when the perceptual anomaly occurs in the setting of a primary psychiatric disorder, the remittance of the paracusias is more independent. Evidence demonstrates that the positive symptoms of schizophrenia respond well to the administration of neuroleptics; however, the actual psychotic disorder does not. Thus, the resolution of the hallucinations does not necessarily indicate the resolution of the underlying thought disorder.[34] Generally, factors that increase the risk of poor treatment response include early age of onset, male gender, and multiple inpatient hospitalizations.

Complications occur when the hallucinations command the patient to hurt himself or others. The paracusias can also be so self-deprecating that they cause the patient to attempt suicide. More common complications result from the side effects of antipsychotics. These can include both short-term and long-term side effects, including extrapyramidal symptoms such as dystonia, tardive dyskinesia, parkinsonism, and metabolic syndrome. Individuals may lack insight and judgment, leading to self-neglect, and may have to be hospitalized involuntarily. Care needs to be taken to build trust and respect with the patients for maintaining regular follow-up even after discharge from hospitals, given a notably high chance of relapse due to non-compliance with medications and appointments.

Patients and their families need to be educated regarding the significance of compliance with the medication plan. Many patients do not adhere to their medication regimens, are lost to follow up, and end up relapsing and being hospitalized. Severely sick patients should be assigned to an assertive community treatment program while providing treatment, rehabilitation, and support services. Other support groups focus on destigmatizing mental illness for the family and the individual. Engaging patients in vocational and art therapy can improve self-esteem and help integrate their functioning. Lastly, patients should be educated about case management services that can assist them by helping coordinate between psychiatrists and social workers, keeping up with the appointments, and making home visits.

There are some limitations in the understanding and strategies within the healthcare system towards auditory hallucinations. Defining the phenomena, suggesting treatment strategies, and providing support are essential. Next, recognizing the gravity of the complications that can occur could prevent self-neglect, suicidal, and homicidal events and minimize medication side effects. While a detailed history and mental status examination are paramount, identifying the cause of auditory hallucinations allows the right selection of management strategies. Antipsychotics are the treatment of choice. Despite the clear-cut strategies, it is important to understand that auditory hallucinations are a sensory perception that require patience and involvement by an interprofessional team to see results. Hence, it is important to raise awareness and education in the inpatient and outpatient staff, customize discharge plans according to the individual with self-management strategies, and communicate discharge plans and safety tools with caregivers and case managers. The outcome of auditory hallucinations depends upon each caregiver's coordination and promptness during the care process. As such, it requires the coordinated activities of an interprofessional healthcare team. This team includes clinicians (MDs, DOs, NPs, PAs), specialists, counselors and social workers, nursing staff, and pharmacists. Open communication between the various disciplines makes improved outcomes and minimized adverse events much more likely.