Disorders of Cognition
A key feature of schizophrenia is pervasive thought disturbances. They struggle to maintain one coherent train of thought and tend to skip from one idea to another with difficulty suppressing irrelevent thoughts. Similar problems arise with irrelevent external stimuli- in normal perception, we can focus on one aspect whilst de-emphasising others e.g. we pay attention to our partner's voice in a crowded restaurant. Schizophrenics on the other hand, often hear/see/feel too much, perhaps because they cannot exclude what is extraneous.
Thought disorders may also be present in the form of broadcasts- thinking one's thoughts are being broadcast to everyone in the room, possibly via the TV of radio-or insertions, which involve hearing voices telling you to do things, often patients believe this to be God.
Delusions are beliefs that result from the misinterpretation of real events.
Many schizophrenics develop ideas of reference, meaning they begin to believe that external events are somehow specifically related to them. The patient may see strangers talking and conclude that they must be talking about them, if he sees people walk by he may believe they are following him; he sees a TV advert and is certain it holds a secret message aimed at him. Eventually, these delusions may be weaved into a whole delusional system in which he may believe, for example, that government agents are talking about him, following him and have taken over the media to spread secrets about him. These are especially common in paranoid schizophrenia.
A common symptom of this subtype is a delusion of persecution. The patient is sure that "they", be it aliens of the F.B.I, are spying and plotting against them. This gradually expands as the patient gathers further evidence that convinces him that his family, psychiatrist- even the woman next door-are all part of the conspiracy.
In contrast to delusions, hallucinations are perceptions that occur in the absence of actual sensory stimulation. These are fairly common amongst schizophrenics. Usually, they are auditory in which the pateint "hears" voices- God, the devil, relatives etc. If they can make out what hey are saying, they will report that they are talking about him, shouting obscenities, threatening, telling him what to do or making accusations about him.
Some clinicians believe that such hallucinations reflect the inability to distinguish vetween experiences that originiate from within and those that originate from without- that is, between memories or fantasies and actual perceptions. For instance, in some auditory hallucinations, some people believe they are hearing voices when in fact it is just themselves talking.
Disorders of motivation and emotion
Motives and feelings often demonstrate disruption and fragmentation. In the early phase, there is often marked emotional overreactivity in which the slightest rejection may trigger an extreme response. Eventually, this sensitivity declines, often to the point that the person shows indifference to their own fate or that of others. This is especially pronounced in long-term schizophrenics, who often stare vacantly with expressionless faces and talk in a flat monotone voice. Strangely, in some patients emotions are present but is largely inappropriate to the situation e.g a patient may burst into laughter after hearing of their relative's death "because she was so pleased at receiving letters with black borders", another may become enraged when someone says hello.
Disorders of Behaviour
Some patients exhibit unusual motor reactions. They can remain motionless for long periods of time and may stand or sit, appearing frozen, in some unusual posture and can maintain this position for hours on end. Then, with no apparent cause, they can become frenzied, loud and violent. This is a symptom of catatonic schizophrenia.
In another subtype known as disorganised schizophrenia (hebephrenia), thought, emotion and behaviour are chaotic. The main symptoms are incoherence (disorganised) speech and marked inappropriateness of behaviour and emotion. Their speech is often strange and babbling, and whilst talking they may giggle or insert silly smiles or grimaces and have sudden fits of laughing and crying. These patients often deteriorate a lot- they lose all concern over personal appearance and hygiene along with the rules of simple social conduct.
Loss of personal contact
A common feature of schizophrenia is a withdrawal from people. In some, this begins quite early, with a history of very few friends and little to no adolescent sexual experience. It is unclear as to why this happens, it may be a consequence of the difficulty in filtering out what is irrelevent, so that the individual withdraws to shield themselves from overstimulation. Alternatively, the withdrawal may reflect a reduced ability to follow the complex rules that govern everyday social interaction.
The individual starts to develop an inner world that becomes more and more private and less in contact with the social world. The withdrawal from others provides few opportunities for the social reality testing through which one's ideas are validated against those of others. As a result, their thoughts become even more idiosyncratic, until they starts to have communication issues. Others may start to avoid them as they cannot understand them and think they're 'weird'. This leads to further withdrawal and idiosyncrasy, until the patient can no longer distinguish between their own thoughts and fantasies and the reality around them. They have lost touch with the world.
Positive and Negative symptoms.
Positive symptoms are excesses of normality, include delusions, hallucinations and bizarre forms of behaviour.
Negative symptoms are deficits and include flattening or absence of affect (emotion) and motivation, speech and language disorders e.g. poverty of speech and disorganised speech, general apathy and avoidance of social activity along with catatonia.