"Hearing voices" in schizophrenia: who's voices are they?

Paranoid schizophrenia is a subtype within the group of schizophrenia disorders. In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), delusions and hallucinations are the first and second symptoms required for the diagnosis of schizophrenia. Empirical data and clinical observations allow us to present the hypothesis that paranoid schizophrenia can be divided into two subgroups: (1) Hallucinatory subgroup, patients with prominent hallucinations and delusions influenced by auditory hallucinations, (2) Delusional subgroup, patients with prominently impaired thought content, in which hallucinations are not significant clinical factors. Furthermore, we believe that auditory hallucinations are not disturbances of perception but rather of thought - or "pseudo-perceptions". According to our hypothesis there are epidemiological and clinical differences between the hallucinatory and delusional subgroups of patients diagnosed with schizophrenia, paranoid type. Patients in the Hallucinatory subgroup have more severe positive and negative symptoms and greater functional impairment than the patients in the Delusional subgroup. A patient deep in thought might not realize that he is thinking (malfunction of thought) but is rather "hearing voices" without external stimulus. Thus, hearing voices is not a disturbance of perception but rather of thought - or "pseudo-perception". The prognosis seems to be poorer for paranoid schizophrenia patients with prominent hallucinations, thus therapeutic rehabilitation programs for hallucinatory patients need to be developed accordingly. Further research is warranted to investigate additional aspects of these two groups.