In 2015 a small survey reported voice hearing in persons with a wide variety of DSM-5 diagnoses, including: *Bipolar disorder *Borderline personality disorder *Depression (mixed) *Dissociative identity disorder *Generalized anxiety disorder *Major depression *Obsessive compulsive disorder *Post-traumatic stress disorder *Psychosis (NOS) *Schizoaffective disorder *Schizophrenia *Substance-induced psychosis However, numerous persons surveyed reported no diagnosis. In his popular 2012 book Hallucinations, neurologist Oliver Sacks describes voice hearing in patients with a wide variety of medical conditions, as well as his own personal experience of hearing voices. Genetic correlations have been identified with<unk> s, but most work with non-psychotic causes of<unk> s is still ongoing. Schizophrenia In people with a psychosis, the premier cause of<unk> s is schizophrenia, and these are known as<unk>  verbal hallucinations (AVHs). In schizophrenia, people show a consistent increase in activity of the thalamic and striatal subcortical nuclei, hypothalamus, and paralimbic regions; confirmed by PET and fMRI scans. Other research shows an enlargement of temporal white matter, frontal gray matter, and temporal gray matter volumes (those areas crucial to both inner and outer speech) when compared to control groups. This implies that functional and structural abnormalities in the brain, both of which may have a genetic component, can induce<unk> s.<unk>  verbal hallucinations attributed to an external source, rather than internal, are considered the defining factor for the diagnoses of schizophrenia. The voices heard are generally destructive and emotive, adding to the state of artificial reality and disorientation seen in psychotic patients. The causal basis of hallucinations has been explored on the cellular receptor level. The glutamate hypothesis, proposed as possible cause for schizophrenia, may also have implications in<unk> s, which are suspected to be triggered by altered glutamatergic transmission. Studies using dichotic listening methods suggest that people with schizophrenia have major deficits in the functioning of the left temporal lobe by showing that patients do not generally exhibit what is a functionally normal right ear advantage. Inhibitory control of hallucinations in patients have been shown to involve failure of top-down regulation of resting-state networks and up-regulation of effort networks, further impeding normal cognitive functioning. Not all who experience hallucinations find them to be distressing. The relationship between an individual and their hallucinations are personal, and everyone interacts with their troubles in different ways. There are those who hear solely malevolent voices, solely benevolent voices, those that hear a mix of the two, and those that see them as either malevolent or benevolent and not believing the voice. Mood disorders and dementias Mood disorders such as bipolar disorder and major depression have also been known to correlate with<unk> s, but tend to be milder than their psychosis-induced counterpart.<unk> s are a relatively common sequelae of major neurocognitive disorders (formerly dementia) such as Alzheimer's disease. Transient causes<unk> s have been known to manifest as a result of intense stress, sleep deprivation, and drug use.<unk> s can also occur in mentally healthy individuals during the altered state of consciousness while falling asleep (hypnagogic hallucinations) and waking up (hypnopompic hallucinations). High caffeine consumption has been linked to an increase in the likelihood of experiencing<unk> s. A study conducted by the La Trobe University School of Psychological Sciences revealed that as few as five cups of coffee a day could trigger the phenomenon. Intoxication of psychoactive drugs such as PCP, amphetamines, cocaine, marijuana and others substances can produce hallucinations in general especially in high doses. Withdrawal from certain drugs such as alcohol, sedatives, hypnotics, anxiolytics, and opioids can also produce hallucinations including<unk> .
Auditory hallucination
Automatism 
Musical hallucinations
Closed-eye hallucination
Automatic behavior
Acholia
Hallucination
Snatiation