The symptoms of schizophrenia fall into two categories — “positive” and “negative” symptoms. Positive symptoms (sometimes called psychotic symptoms) refer to symptoms that appear; negative symptoms refer to elements that are taken away from a person.
Positive Symptoms
Positive symptoms include:
- delusions (fixed, false beliefs that are not consistent with the person’s culture, and have no basis in fact)
- hallucinations (people hear, see, taste, smell or feel something that does not actually exist)
- disorganized thought (unconnected thoughts that make it impossible to communicate clearly with other people)
- disorganized mood (finding it hard to express feelings; feeling inappropriate or intense bursts of emotion; feeling empty of any emotions)
- disorganized behaviour (cannot complete everyday tasks such as bathing, dressing appropriately and preparing simple meals)
- changes in sensitivity (more sensitive and aware of other people; or withdrawn and seeming to pay no attention to others).
Negative symptoms
Negative symptoms include:
- slowing of physical activity levels or, more rarely, overactivity
- reduced motivation, for example problems finishing tasks or making long-term plans
- loss of interest in the feelings and lives of others
- less concern for personal appearance.
Phases of Schizophrenia
Schizophrenia has three phases — prodromal (or beginning), active and residual. These phases tend to happen in order and appear in cycles throughout the course of the illness. During a lifetime, people with schizophrenia may become actively ill once or twice, or have many more episodes.
Prodromal phase
In the prodromal phase, people may begin to lose interest in their usual activities and to withdraw from friends and family members. They may become easily confused, have trouble concentrating, and feel listless and apathetic, preferring to spend most of their days alone. They may also become intensely preoccupied with religion or philosophy. This phase can last weeks or months.
Active phase
During schizophrenia’s active phase, people may have delusions, hallucinations, marked distortions in thinking and disturbances in behaviour and feelings. This phase is often the most frightening to the person with schizophrenia, and to others.
Residual phase
After an active phase, people may be listless, have trouble concentrating and be withdrawn. The symptoms in this phase are similar to those outlined under the prodromal phase.
Causes
Research strongly suggests that schizophrenia involves problems with brain chemistry and structure and is thought to be caused by a combination of genetic and environmental factors, as are many other medical illnesses.
One percent of the world’s population or one in every 100 people will develop the disorder in their lifetime. The most common onset is in the teens and 20s. It is uncommon for schizophrenia to be diagnosed before 12 years of age or after the age of 40.