Positive Symptoms

Positive symptoms are not positive in the sense of being affirmative. They are positive in the sense of existing or being present as opposed to being absent or deficient. Positive symptoms are seen as additions to normal functions. These additional, unwanted contributions exaggerate or distort hearing, speaking, or thinking.

Positive symptoms include:

  • Delusions, such as the patient's belief that others are plotting against him or that he is a great historical personality

  • Hallucinations, which are usually auditory and involve hearing voices •

  • Strange, distorted, or larger-than-life ideas, behavior, or perceptions •

  • Delusions

    Delusions are firmly held beliefs in things that are not real but have great significance to the patient. They cannot be explained by a person's religion, philosophy, or cultural background. Instead, they are often strange ideas that most people who do not have schizophrenia would recognize as obviously unlikely or untrue.

    A key feature of a delusion is that the patient will go on believing it even after he is presented with strong evidence that the belief is highly unlikely or obviously untrue. There are at least nine types of delusions seen in schizophrenia, and some patients may suffer from more than one.

    Types of Delusions

  • Grandeur. A patient may have a single, overriding delusion. He may believe, for example, that he has been chosen by God for a particular task or that he is extraordinarily powerful, creative, skilled, or otherwise exceptional.

  • Thought control. A patient may believe that an outside force is putting thoughts into his mind.

  • Passivity. A patient believes he is being controlled by an outside force or influence. He might be convinced that a space satellite or some form of electromagnetic radiation is controlling him.

  • Reference. Anytime someone attributes a special, personal meaning to an unrelated event, thing, or occurrence, it is a delusion of reference.

  • Poverty. A patient believes he has no money or security despite evidence to the contrary.

  • Persecution. These paranoid-type delusions affect as many as one-third of schizophrenia patients. Patients may believe they are the subjects of highly elaborate plots.

  • Guilt. People with delusions of guilt are convinced that they have done something unforgivable.

  • Sickness. A physically healthy patient who is convinced he has a terrible disease has a delusion of sickness or ill health.

  • Jealousy. An example of a delusion of jealousy would be an unshakable conviction, despite lack of plausible evidence, that one's spouse or partner has been unfaithful.

  • Adapted from the DSM-IV.


    While it may be an oversimplification, one way to understand hallucinations is to think of dreaming. When we dream, we see and hear people and things that are not there; our brains generate images from stores of memories. You can think of hallucinations as being similar to dreams except that they occur while a person is awake. Some people may experience hearing their name being called or a knock at the door as they are falling asleep (hypnagogic hallucinations) or as they are waking up (hypnopompic hallucinations). These are considered normal if they are transient and do not affect a person's behavior or cause them any emotional distress.


    Hallucinations are apparent perceptions that originate inside, instead of outside, a person's brain. Only the person experiencing the hallucination can sense it. Illusions are different. They have an outside source, but they are misinterpreted by the person who senses them.

    The brain normally takes in information through sense organs. Nerves outside the brain coming from the eye, ear, nose, mouth, or skin pass information to cells in the brain. The brain processes the input and creates the conscious awareness of whatever sight, sound, smell, taste, or touch started the process. In a hallucination, cells in the brain that process information receive abnormal inputs from other parts of the brain rather than from cells that are outside the brain in close contact with the environment. The result is understandable: the brain thinks it senses something.

    Alternatively, information-processing cells inside the brain may misinterpret input from outside the brain. The sound of a dog's barking, for example, might be misinterpreted as a human voice to create the hallucination that the dog is speaking.

    Hallucinations associated with schizophrenia are most commonly auditory and involve hearing voices. The next most common are seeing things or people that are not there. Hallucinations may involve other senses, including touch, taste, and smell. Such non-auditory hallucinations, however, are rare in schizophrenia.

    The voices that plague so many people with schizophrenia are very real to them, as real as the voices you hear in conversation every day. The voices may carry on conversations that the patient can overhear, or they may speak directly to the patient.


    Hallucinated voices may conduct a commentary on a person's actions or issue commands. Too often, they torment their victims, urging them to do unpleasant, disturbing things and threatening the person if they are not obeyed. Be aware of this when someone with schizophrenia seems unreachable, upset, anxious, or agitated. Voices may command a patient to hurt herself or others.

    Visual hallucinations are more common when drug abuse or another identifiable medical condition is the cause. Other medical conditions are usually the source of hallucinations involving touch and smell.

    Disorganized Thought and Speech

    People with active schizophrenia symptoms often don't think logically. The exception might be those suffering from the paranoid form of the disease. Their delusion aside, they can sometimes function passably in society. Otherwise, people with schizophrenia may not be able to sort out what is relevant from what is not during a conversation or in a social situation.

    Disordered thinking can result in very short attention spans, fleeting thoughts, and lack of focus. These symptoms may overlap with another class of symptoms associated with the disease: cognitive dysfunction.

    Thought Disorder

    Peculiar speech appears to reflect illogical thought patterns in some patients with schizophrenia. It is therefore one of the symptoms that most readily suggests to a layperson that a patient suffers from a mental disorder.

    The seemingly illogical train of reasoning and observation that accompanies formal thought disorder makes these patients very difficult, if not impossible, to understand at times. People who are unfamiliar with mental illness are baffled and often disturbed or frightened by such speech.

    Thought disorder can take several forms. The patient may change topics rapidly, from sentence to sentence or even from the beginning to the end of a single sentence. Clinicians describe these seemingly unconnected shifts as loose associations. They refer to the symptom as derailment, as if the train of thought cannot stay on a straight, continuous track.

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