Schizophrenia
According to the DSM-IV, the characteristic symptoms that must be present for at least 6 months in order for a diagnosis of schizophrenia to be established are:
A. Characteristic symptoms: Two or more of the following symptoms are present, each for a significant portion of time during a 1-month period (or less if successfully treated):
• Delusions
• Hallucinations
• Disorganized speech
• Grossly disorganized or catatonic behavior
• Negative symptoms, e.g., affective flattening, lack of volition
(Only one Criterion A symptom is required if the delusions are bizarre, or if the hallucinations consist of voices providing a running commentary on the person’s behavior or thoughts, or two or more voices conversing with each other.)
- B. Social/occupational dysfunction: Functioning in areas such as work, interpersonal relationships, or self-care is markedly below the level achieved prior to the onset of the disorder.
C. Duration: At least 6 months.
D. Exclusion of schizoaffective disorder or mood disorders.
E. Exclusion of substance abuse or general medical conditions.
F. Exclusion of an association with a pervasive developmental disorder.
Delusions are false beliefs that cannot be corrected even when the person is confronted with evidence to the contrary. They are not consistent with the cultural and religious norms and beliefs of the community to which the person belongs and impair the person’s social functioning.
Hallucinations are perceptions that the patient believes to be real despite evidence to the contrary. They may occur in several forms. Auditory hallucinations are the most common type. They may consist of sounds, familiar or unfamiliar voices, or ongoing conversations between several voices. Hallucinations may also be visual, sensory, olfactory, or tactile.
Delusional Disorder
Delusional disorder develops later in life than schizophrenia, is not characterized by progressive deterioration, and does not impair the patient’s affect, intellectual abilities, or volition.
It is characterized by paranoid delusions involving persecution, magic, poisoning, grandiosity, or erotomania, which also determine the specific subtype.
Brief Psychotic Disorder
Brief psychotic disorder is characterized by psychotic symptoms lasting from one day to one month, with sudden onset and complete resolution within one month.
References:
Kaplan & Sadock: Synopsis of Psychiatry, twelfth edition
Kaplan & Sadock: Pocket Handbook of Clinical Psychiatry, fifth edition;
American Psychiatric Association: Diagnostic Manual of Mental Disorders, 1994;
Robert J. Waldinger: Psychiatry for Medical Students, third edition, translated by Anastas Suli.