General signs and symptoms

This category includes main signs and symptoms of schizophrenia.

Dermatoglyphics

What are dermatoglyphics? Dermatoglyphics, also referred to as epidermal ridges, are the distinct patterns and lines on the hands and fingers. These ridges appear on the hands between weeks 6 and 15 during foetal development, and remain largely unchanged after this period. Alterations in the patterns and counts of dermatoglyphics may be an indication of disruption to foetal development in the early- to mid-gestation period. A triradius occurs where three ridge systems meet at a point, and occurs four times on the palm, at the base of each of the four digits (a, b, c, and d). Dermatoglyphic indices include:…

Disorganised symptoms

What are disorganised symptoms? Key features of the symptoms of disorganisation include disorganised speech and behaviour, as well as inappropriate affect. Severely disorganised speech is difficult to follow, being incoherent, irrelevant and/or illogical. These symptoms are sometimes referred to as positive formal thought disorder. Disorganised speech may also be deprived of content, which is sometimes referred to as negative formal thought disorder symptoms. Disorganised behaviour includes bizarre or inappropriate behaviour, actions or gestures. Inappropriate (incongruous) affect involves exhibiting incorrect emotional responses for a given context. Symptoms of disorganisation have been identified as risk factors for poor illness outcome, and have…

Dissociation

What is dissociation? Dissociation is described as disruption or discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, or behaviour. Common dissociative experiences include mild forms of absorption, such as daydreaming. Less common and more severe dissociative experiences include amnesia, derealisation, depersonalisation, and fragmentation of identity. Dissociative features may play a role in the pathology of schizophrenia. What is the evidence for dissociation? Moderate to high quality evidence finds more dissociation in people with schizophrenia than controls. Moderate quality evidence finds a medium-sized association between childhood adversity and dissociation. Moderate to low quality evidence…

Early detection

What is early detection of psychosis? Early detection refers to the correct identification of individuals who are at high risk of developing schizophrenia, with an emphasis on the development of frank psychosis. Several assessment tools have been constructed to effectively identify such individuals. Sensitivity of an assessment tool refers to the proportion of people who develop psychosis that were previously identified by the assessment tool as being at high risk. Specificity is the proportion of people who do not develop psychosis that were previously identified as not being at high risk. Assessment tools therefore aim to have both high sensitivity…

Functional laterality

What is functional laterality?  Functional laterality refers to a natural asymmetry in left or right-side dominance, for example in terms of handedness, or brain function. Handedness refers to the preference for using one hand over the other for certain tasks. Right-handed people show increased dexterity in their right hand, left-handed people show increased ability the left hand. People may also be ‘mixed’ handed and show different hand preference for different tasks. Listening tasks can be used to assess language lateralisation. People with schizophrenia may show differences in handedness or footedness, as well as altered visual and auditory dominance that may…

Minor physical anomalies

What are minor physical anomalies? Minor physical anomalies (MPAs) are subtle anatomical deviations that have little functional or aesthetic impact. They may be traced to events occurring prenatally and may represent risk markers for underlying illness susceptibility. MPAs may be important risk indicators when an individual is already at high risk of developing psychosis, for example, having a first-degree relative with psychosis, and when multiple MPAs occur together in one individual. What is the evidence for minor physical anomalies? Moderate to high quality evidence finds a large increase in overall MPA scores in people with schizophrenia compared to controls. There…

Morphometrics

What is morphometrics?  Morphometrics is the measurement of the variation in the structure or form of organisms. In the mid-1900s, William Herbert Sheldon introduced the notion that there were three components that determine the morphology of a human individual: mesomorphy (musculoskeletal robustness relative to height); endomorphy (relative fatness); and ectomorphy (relative erectness or slenderness). The study of body shapes and their prevalence in both physical and mental disorders may provide insight into the biology of and risk for schizophrenia. What is the evidence for morphometrics? High quality evidence shows people with schizophrenia are often slighter shorter in height than people…

Movement disorders

What are movement disorders?  Movement disorders have been reported in people with schizophrenia, with tardive dyskinesia among the most commonly reported. This disorder is a ‘hyper-kinetic’ (excessive movement) disorder, characterised by jerky, involuntary movements, usually of the face and/or limbs. Parkinsonism is another movement disorder associated with schizophrenia, and is a ‘hypo-kinetic’ (reduced movement) disorder, characterised by slowness of movement and rigidity. Movement disorders are primarily associated with the use of antipsychotic medications, however they have also been reported in people who are antipsychotic-naïve. What is the evidence for movement disorders in schizophrenia? Moderate to high quality evidence suggests a…

Negative symptoms

What are negative symptoms? The ‘negative symptoms’ of schizophrenia refer to an absence of normal functions. This includes a scarcity of facial expressions of emotion, reduced frequency and range of gestures and voice modulation, restricted eye contact, poverty of speech, reduced social interaction, reduced motivation, poor hygiene, and reduced experience of pleasure often manifesting as scarcity of recreation, inability to experience closeness, and reduced interest in any sexual activity. Deficit syndrome is a subtype of schizophrenia with persisting negative symptoms that is described by specifically defined assessments used primarily for research. What is the evidence regarding negative symptoms? Moderate to…

Neurological soft signs

What are neurological soft signs? Neurological soft signs (NSS) are neurological abnormalities that can be identified by clinical examination using valid and reliable testing measures. They are referred to as ‘soft’ because they not related to a specific brain area, or part of a defined syndrome. Categories of NSS are commonly grouped into three categories; integrative sensory functioning, motor coordination, and complex motor sequencing. Integrative sensory functioning includes impairments in sensory perception such as audio-visual integration or tactile recognition. Motor coordination involves general coordination, balance and gait. Complex motor sequencing involves complex motor tasks, such as repetitive alternating hand positions….

Olfactory functioning

What is olfactory functioning?  The olfactory system is the sensory system used to interpret and perceive smell. Olfactory functioning is hierarchical and involves lower-order processing (detection of the stimulus) and higher-order processing (discrimination and identification of the stimulus). Odour detection occurs at the lowest chemical concentration needed to register an odourant. Odour discrimination involves comparing the differences between multiple stimuli, judging odours as pleasant or unpleasant, or comparing the relative concentration of odours. Odour identification draws on a person’s knowledge and memory to correctly label the smell. What is the evidence for altered olfactory functioning in schizophrenia? Moderate to high…

Pain sensitivity

What is pain sensitivity? Pain is defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage” and pain is perceived as both a sensory and emotional experience. There is an important distinction between the body’s responses to pain (nociception) and the subjective experience of pain. Measured outcomes of pain perception include pain reactivity, sensory threshold, pain threshold, and pain tolerance, as well as self-reporting of the pain experience. What is the evidence for pain sensitivity? Moderate to high quality evidence suggests schizophrenia is associated with…

Personality and temperament

What is personality and temperament? Personality and temperament are thought to be relatively stable over time and include emotional, reactive, and attentional traits. Studies assessing personality and temperament use “positive” stimuli, which generates pleasurable emotional states, “negative” stimuli evokes avoidant, threat, sadness, or other negative emotional states, and “neutral” stimuli generally provokes no response. Hedonic and aversive emotions refer to the positive or negative emotions following stimuli presentation. One of the main personality models is the Five-Factor Model which includes five traits of; 1) neuroticism: vulnerability to emotional instability and self-consciousness, 2) extraversion: predisposition towards sociability, assertiveness and social interaction,…

Positive symptoms

What are positive symptoms?  Positive symptoms are a well-documented feature of schizophrenia and are arguably the most recognisable and conspicuous symptoms. Positive symptoms include hallucinations and delusions. Hallucinations are defined as a perceptual experience that occurs in the absence of any external sensory input, and are most commonly auditory, but can occur in any modality. Delusions are distortions or exaggerations of inferential thinking, which lack any logical consistency, are not explained by cultural beliefs, and persist regardless of contradictory evidence. Persecutory delusions involve the belief that people are “out to get” the individual, resulting in a lack of trust in…

Psychotic relapse

What is psychotic relapse? Psychotic relapse is the reoccurrence of previously treated psychotic symptoms.  Effective early recognition may offer the potential for early intervention to prevent relapse, such as medication adjustment, psychosocial treatments, social support and stress reduction. Early warning signs are subjective experiences, thoughts and behaviours that occur immediately prior to a psychotic relapse, which signal to the patient or their family that their condition is deteriorating. It is important that these early signs be identifiable by family members or carers, as patients may minimise or disguise these symptoms in order to appear healthy or to avoid hospital readmission….

Sleep disturbance

What is sleep disturbance? Typically, sleep follows a characteristic pattern of four stages, where stage 1 is a state of drowsiness and early sleep, stage 2 comprises the largest component of the sleep cycle and is the first complete loss of awareness of the external environment, stage 3 is a deep slow-wave sleep, and the fourth stage is rapid eye movement (REM) sleep where muscle paralysis and memorable dreaming occurs. Sleep disturbances include changes in sleep time, sleep latency (the length of time it takes from full wakefulness to sleep) and sleep efficiency (the amount of time spent asleep while…

Temperature regulation

What is temperature regulation? Changes in the homeostatic regulation of body temperature can involve increased or decreased body temperature in a neutral environment (baseline temperature), altered response to a temperature stimulus (heat or cold stress), changes to the normal differences between morning and nighttime body temperatures (diurnal and circadian variation), variations in the range of typical body temperature changes during the day, and changes to typical differences between core and peripheral body temperatures. What is the evidence for temperature regulation? In antipsychotic-free patients, moderate to low quality evidence suggests baseline temperature is reduced, there is less daily variation in temperature,…

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