Paranoid schizophrenia is the most commonest form of schizophrenia. The person presents with auditory hallucinations (voices) which might be accompanied by delusions. These auditory hallucinations could be of any nature (see positive symptoms). The paranoid delusions can occur independently of the auditory hallucinations, ie they do not occur as a result of the hallucinations. Or it can be secondary to the threatening nature of the voices.
Commom themes are ones of persecution. They feel threatened or insulted by the voices. Past examples I have encountered are, they believe their loved ones are poisoning them, that they are been monitored by the Police, that other associates are plotting against them and talking about them, or that the neighbour is putting poisonous fumes through the ventilation pipes.
In the early stages of paranoid schizophrenia, the person's thought processes usually remain intact, ie they are able to convey what they are thinking in a logical manner. As the psychotic episode worsens, they might start developing thought disorder and the thought content becomes non-sensical. They could develop any of the symptoms of thought disorder (see positive symptoms).
Their behaviour will vary depending on severity of psychotic episode, personality style, coping mechanisms, and support structures. A very small minority of people are able to ignore these psychotic experiences and go on about with their lives as normally. Others can present as irritable, easily provoked, aggressive, threatening and assaultative. This is an understandable response to an environment which they perceive as being very hostile, and in which they feel their lives might be at risk. Others can become secretive and reclusive, hiding away from people they believe are their enemies. And then of course there is a whole spectrum of behaviour between these 2 extremes.
In paranoid schizophrenia, insight and judgement are often impaired. This means that despite having these experiences such as hearing voices, patients often fail to recognise that they are ill. Patients appear to be talking to themselves, but are in fact responding to their voices.
There can be changes in mood and anxiety. Sometimes clinical depression can be associated with a psychotic illness and patients can have a co-morbid major depressive episode. Co-morbid anxiety disorders are also quite common. .