The symptoms of schizophrenia can be categorised into three broad categories, namely, positive symptoms, negative symptoms and cognitive symptoms.
Psychotic behaviours constitute positive symptoms of schizophrenia. These behaviours are not seen in healthy people. A person with positive symptoms often loses touch with reality and the symptoms can come and go. The symptoms may vary in severity from hardly noticeable to severe. Positive symptoms of schizophrenia include:
a. Hallucinations—the person sees, hears, smells or feels things that don’t really exist. Hearing voices is the common type of hallucination in schizophrenia and it usually starts much before family and friends notice the problem.
b. Delusions— these are firmly-held ideas by the person, which do not change even though there is clear and obvious evidence that it isn’t true. More than 90% of people with schizophrenia have delusion. Some common delusions in schizophrenia include:
c. Thought disorders—the person develops unusual or dysfunctional ways of thinking. In the “disorganized thinking” type of thought disorder, the person has trouble organising his or her thoughts or connecting them logically. Another form of thought disorder is called "thought blocking." In this, the person feels as if there is a loss of thought or the thought has been taken out of his or her head.
d. Movement disorders—these appear as agitated body movements. The person may do a certain motion repeatedly. Some people may become catatonic i.e. the not move and respond to others.
Negative symptoms cause disruptions to normal emotions and behaviours. They are often difficult to diagnose as part of schizophrenia and can be mistaken for depression or other conditions. People, who develop negative symptoms usually, need help with everyday tasks. The negative symptoms are:
In most cases, cognitive symptoms are subtle and it may be difficult to associate these symptoms with schizophrenia. They are generally detected when others are performed. Some of the cognitive symptoms include:
Cognitive symptoms limit the person’s capability to lead a normal life and earn a living and can therefore, be a cause great emotional distress.