Hallucinations and delusions are the hallmarks of schizophrenic disorders. A majority of patients suffer auditory hallucinations—primarily hearing voices (including multiple voices at once) that are not apparent to others. Delusions are common and often focus on persecution, control, and spying.

The “voices” may attempt to “control” or influence the afflicted patient during a psychotic episode. These voices may also be interpreted by the patient as being involved in attempts to spy upon or otherwise interfere with the patient. Accordingly, a fervent belief in conspiracy theories is a common signifier of possible delusions. Acute schizophrenia is distinguished from other forms of the disease by its episodic nature. Other forms tend to be essentially chronic, while acute schizophrenia patients often suffer severe affective (behavioral) symptoms, including bewilderment and a sense of disorientation, which may come and go unpredictably. Given the occurrence of hallucinations and delusions, it may be difficult for patients to distinguish between reality and fantasy.

Behavioral and Physical Symptoms

Other symptoms may include dysfunctional social or work-related relationships and a decline in the patient’s ability to care for himself properly. If onset is early, patients may never achieve an age-appropriate level of independence, including the ability to dress and groom properly. Another hallmark of schizophrenia is the so-called “flattened” affect, which can be described as an oddly emotionless and robotic demeanor when interacting with others.

Physical symptoms may include the various behaviors associated with catatonia; recurrent posturing, grimacing, and remaining still for prolonged periods of time. These symptoms may occur in reaction to auditory hallucinations or as stand-alone symptoms. Verbal symptoms may include stopping in mid-sentence, only to resume speaking, on a different tangent, after an uncomfortably long period, or speaking nonsense (dubbed “word salad;” random words are strung together, in no logical order). 

Positive & Negative Symptoms

Schizophrenia symptoms are further characterized as either positive or negative. Positive symptoms—including hallucinations, delusions, disordered thoughts and speech, etc.—are psychotic symptoms that do not occur in healthy individuals. Positive symptoms generally respond well to drug therapy.

Negative symptoms are characterized by a lack of normal behaviors and responses. They may include an inability to experience pleasure (anhedonia), a lack of desire to form emotional attachments or social connections (asociality), and a lack of emotion, among others. Negative symptoms do not respond as readily to drug therapy and are associated with poor quality of life more often than positive symptoms.

Grouping by Symptoms

Occasionally, mental health professionals will group patients into categories such as paranoid, catatonic, hebephrenic (characterized by childish, silly behavior), etc. depending on the patient’s predominant symptoms. However, most patients will manifest any number of symptoms over time, rendering this approach somewhat misleading. Pending changes in official diagnosis criteria (endorsed by the American Psychiatric Association) will eliminate some of these subcategories.

Schizophrenia and Violence

Public safety officials have traditionally believed that people suffering from psychosis and/or schizophrenia are more likely to commit violence, including homicide. But a recent meta-analysis (a study that scrutinized data collected from many sources over a number of years) concluded that, while mentally unstable individuals are somewhat more likely to commit violent crimes, substance abuse was usually a factor. This suggests that schizophrenia per se is not associated with an increased tendency towards violent behavior, provided an affected individual is not abusing illicit drugs. In fact, the increased risk of violence among schizophrenics who abuse drugs is similar to the incidence of violent behavior among drug-abusing “normal” individuals.