The onset of schizophrenia is typically in the late teens and the mid-30s. About 1% of the population of cultures suffers from schizophrenia during their lives. The symptoms vary somewhat but typically include problems with attention, thinking, social relationships, motivation, and emotion.
Physical and Psychological Symptoms of Schizophrenia
Physical/ behavioral symptoms:
- Schizophrenics may experience psychomotor poverty (lack of movement) and in extreme cases catatonia, when awkward postures are assumed and the schizophrenic remains motionless in this position for hours at a time. They can exhibit “waxy flexibility” during which their body can be manipulated into different positions.
- Schizophrenics may fall into a catatonic stupor, during which they lie motionless and appear unaware of their surroundings but are fully conscious throughout.
- Or increased motor activity can occur, such as stereotypy, purposeless, and repetitive movement.
- Disorganised, chaotic, and bizarre behavior can be linked to other symptoms, e.g. covering up all the windows with black paper as a result of cognitive disturbance.
- Hallucinations: auditory hallucinations are most common when the schizophrenic hears voices that are often abusive or offer a critical running commentary on their behavior.
- Visual, smell, and taste hallucinations may also be experienced but are less common.
Thought disorders include delusions and thought interference.
- Delusions of grandeur, persecution, paranoia, and control (sometimes known as alien control symptoms as the schizophrenic believes that their behavior is under external control) can occur, which can develop during the course of the illness into an increasingly complex web of delusion.
- Thought insertion (a belief that ideas are being planted in their mind), withdrawal (the belief that thoughts are being removed from their mind), and broadcasting (a belief that others can “tune into” their thoughts) can occur—these are collectively known as thought interference symptoms.
- Cognitive impairments include intellectual deficits in learning and memory.
- Most evident are the language impairments such as repeating sounds (echolalia), inventing words (neologisms), jumbled speech (word salad), and nonsensical rhyming (clang associations). The speech is characterized by incoherence and abrupt changes of topic due to cognitive distractibility (inability to maintain a train of thought).
Schizophrenics usually show social withdrawal and may have always lacked social skills. They have little interest in social interactions and do not gain pleasure from them, and so may be aloof, reclusive, and emotionally distant even before the onset of the disorder.
- Symptoms can include a lack of emotion (emotional blunting) or inappropriate affect (e.g. giggling when told of bereavement).
- One-third of patients suffer depressive symptoms and one in eight patients meet the criteria for a mood disorder as well as schizophrenia and so tend to be diagnosed with schizo-affective disorder. Apathy and a lack of drive, interest, personal care, and hygiene are common and can be linked to the depressed state.
Classification of Schizophrenia
DSM-IV (Diagnostic and Statistical Manual, 4th edition; see A2 Level Psychology page 378), which is the American classification system, and ICD-10 (International Classification of Diseases), the tenth edition of which was published by the World Health Organization in 1992 (ICD-10; see A2 Level Psychology page 378), are the two most common classification systems.
The DSM-IV diagnostic criteria are:
- Two or more of the symptoms identified above for a period of over 1 month. One symptom only is needed if the delusions are bizarre or if the hallucination is critical and abusive of the individual’s behavior.
- The disturbance must be evident over a significant period of time, at least 6 months, including 1 month of pronounced symptoms.
- The symptoms must have led to a failure to function in social and occupational roles.
The ICD-10 criteria are very similar to those used in DSM-IV. The main difference being DSM-IV requires evidence of continuous disturbance for at least 6 months, whereas ICD-10 requires that symptoms must be present for most of the time over a 1-month period.
Types of schizophrenia
DSM-IV identifies five types of schizophrenia: disorganized, catatonic, paranoid, undifferentiated, and residual.
Another common classification is into the positive symptoms (hallucinations, delusions, thought disturbances) of type I schizophrenia or acute disturbance; and the negative symptoms (lack of interest, emotion, motivation, social withdrawal) or type II schizophrenia or chronic disturbance.