The presence of delusions and the complexity of delusions and hallucinations increase with age.

Hallucinations (mainly auditory) occur more commonly than delusions.

Neurodevelopmental disorders or their features during childhood.

Poor social, academic, or occupational function.

History preceding the onset of psychosis.

Diagnostic criteria are identical to those used for adults (see “Diagnostics” below).

Definition: onset of schizophrenia Metabolic abnormalities: hypertension, diabetes, hyperlipidemia.Neurological abnormalities: sensory disturbances and impaired coordination.Apathy : lack of emotion or concern, especially with regard to matters that are normally considered important.Anhedonia : inability to feel pleasure from activities that were formerly pleasurable or from any new positive stimuli.Alogia: impaired thinking that manifests with reduced speech output or poverty of speech (e.g., always replying to questions with one-word answers).Avolition: reduced or absent ability to initiate purposeful activities.Flat affect: reduced or absent emotional expression.Catatonia (See “Subtypes and variants” below.).Grossly disorganized behavior : an abnormal behavior characterized by inadequate goal-directed activity (e.g., purposeless movements) and bizarre emotional responses (e.g., smiling or laughing when inappropriate).Disorganized thought or disorganized speech: e.g., loose associations, word salad, tangential speech.

Delusions, e.g., grandiosity, ideas of reference, paranoia, persecutory delusions.Hallucinations and/or illusions ( auditory hallucinations are most common ).Positive symptoms of schizophrenia Psychosis Schizophrenia typically manifests with a prodrome of negative symptoms (e.g., social withdrawal) and psychosis that precedes the positive psychotic symptoms (e.g., hallucinations and bizarre delusions).

Flat affect schizophrenia