Schizophrenia: A broad range of symptoms

Source (slide): APA 2013, Pages 99–102; APA 2000, Page 299; Wilk et al. Neuropsychology 2005; 19 (6): 778–786, Page 778; NICE clinical guideline 178, Page 4.

Source (notes): APA 2013, Pages 99–102; APA 2000, Page 299–302; Wilk et al. Neuropsychology 2005; 19 (6): 778–786, Page 778; NICE clinical guideline 178, Page 4; Tandon et al. Schizophr Res 2009; 110: 1–23, Table 1; Jones & Buckley. Schizophrenia 2006, Page 7.

Patients with schizophrenia experience a broad range of symptoms including positive, negative, and cognitive symptoms.^{[APA, 2013; APA, 2000]} Mood symptoms, such as, depression, anxiety, anger, hostility, and aggression, may also be present.^{[APA, 2013]}

Positive symptoms

Positive symptoms appear to reflect an excess or distortion of normal functions, and include distortions in:^{[APA, 2013; APA, 2000]}

• thought content (delusions)
• perception (hallucinations)
• language and thought process (disorganised thought/speech)
• self-monitoring of behaviour (grossly disorganised or catatonic behaviour).

Negative symptoms

Negative symptoms reflect a decline in, or loss of, normal functions, and include:^{[APA, 2013; APA, 2000]}

• diminished emotional expression and a decrease in motivated self-initiated, purposeful activities (avolition)
• alogia (diminished speech output)
• anhedonia (decreased ability to experience pleasure from positive stimuli)
• asociality (apparent lack of interest in social interactions).

Cognitive symptoms

Cognitive symptoms are considered to be a key component of schizophrenia,^{[Wilk et al. Neuropsychology 2005]} and include impairments in:^{[APA, 2013]}

• attention
• episodic memory
• executive functions (including language function)
• working memory
• processing speed
• inhibitory capacity.

Clinical manifestations of patients with schizophrenia are very variable.^{[NICE, 2014]} Individuals with schizophrenia experience their own distinct combination of symptoms with a degree of severity that varies between patients and throughout the course of the illness, such that no two cases of schizophrenia are ever exactly the same.^{[Tandon et al. Schizophr Res 2009; Jones & Buckley. Schizophrenia 2006]}

References:
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fourth Edition. Text Revision (DSM-IV-TR™). © 2000 American Psychiatric Association, Washington, DC. 299–302.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition (DSM-5). © 2013 American Psychiatric Association, Arlington, VA. 99–102.

Jones PB, Buckley PF. Introduction and Background. In: Jones PB, Buckley PF, eds. In Clinical Practice Series. Schizophrenia. © 2006 Elsevier Limited.

National Institute for Health and Care Excellence (NICE). Psychosis and schizophrenia in adults: treatment and management. NICE clinical guideline 178. March 2014.

Tandon R, Nasrallah HA, Keshavan MS. Schizophrenia, ‘just the facts’. Clinical features and conceptualization. Schizophr Res 2009; 110 (1–3): 1–23.

Wilk CM, Gold JM, McMahon RP, et al. No, it is not possible to be schizophrenic yet neuropsychologically normal. Neuropsychology 2005; 19 (6): 778–786.