Schizophrenia: symptoms, causes and predisposition

By Cristiano Antonino On Mar 27, 2023

The term schizophrenia (from the German schizophrenie, from the Greek σχιζο ‘to separate/separate’ and -phrenie from the Greek ϕρενία meaning ‘mind’) is a psychic disorder in which cognitive, emotional and behavioural alterations coexist

Approximately 1.1% of the population over the age of 18 is affected, and it appears to have an aetiopathogenesis from both genetic and environmental factors.

According to the criteria of the Diagnostic Manual of Mental Disorders, DSM-5, to make a diagnosis of schizophrenia there must be at least two symptoms present for a month

delusions,
hallucinations,
disorganised speech (derailment or incoherence),
coarse, disorganised or catatonic behaviour,
negative symptoms (anhedonia, apathy, abulia, asthenia).

The World Health Organisation (WHO) refers to the most ‘significant mental disorder (or group of disorders), the causes of which remain largely unknown.

Schizophrenia involves a complex of disturbances in thinking, perception, affectivity and social relations.

No society or culture anywhere in the world is free of schizophrenia, which makes it all the more evident that this mental disorder is a serious public health problem’.

Some definitions of schizophrenia tell us:

“disintegration of the unity of the psychic and moral person, with possible superimposition of heterogeneous pseudo-personalities; begins mostly in youth and, progressing, leads to dementia; early dementia”;
“group of mental disorders characterised by a profound alteration of the relationship with reality, personality dissociation, autism and other disorders. It has mostly juvenile onset and slow course with progressive worsening’.

Symptoms of schizophrenia

Symptoms of schizophrenia are commonly divided into negative and positive.

Negative symptoms are:

affective flattening and emotional isolation;
difficult planning;
difficulty using concepts (sometimes creating neologisms);
inability to experience pleasure and interest (anhedonia, apathy, abulia);
depression;
sense of helplessness and despair;
isolation and social withdrawal;

Positive symptoms are:

hallucinations (alterations in perception in the absence of a real stimulus);
delusions (bizarre ideas that do not correspond to reality);
disorganisation of the content and form of thought;
psychomotor tension and agitation.

Behavioural alterations are:

circadian alterations of the sleep-wake rhythm;
lack of purpose and aim;
disorganised/confused thinking (illogical speech, bizarre ideas and behaviour);
delusions (bizarre ideas, unassailable beliefs, denial)
altered sense of self and reality
abnormal reactions to manageable events.

Incidence and prevalence of schizophrenia

After anxiety disorders and depression, schizophrenia is the second most prevalent psychiatric disorder in the world with age of onset between 15 and 24 years and prevalence: 8 people per 1000 (0.8 % world population: more than 45 million people), incidence: almost 2 million new cases per year (Between 0.2 and 0.7 % per year).

Causes of schizophrenia

The prenatal and natal periods (intra-uterine factors, birth trauma, parental bonding, brain damage) give us a genetic predisposition to schizophrenia.

Some of the causes on the etiopathogenesis of the disorder, from recent studies, tell us about brain lesions, or prenatal damage such as depletion of frontal lobe and limbic system functions, or viral infections during the second trimester of pregnancy.

In the biological model of the disorder, there is biochemical damage such as malfunction of the dopaminergic system.

The developmental period of the individual, from birth onwards, gives us vulnerability to schizophrenia.

On the other hand, some studies speak of the role that stressful situations or life events that require great effort to adapt have on the onset and course of schizophrenia spectrum disorder.

The psychological model of the onset of the disorder, on the other hand, takes into account the individual’s developmental stages in the maturation process, relational dynamics, traumatic emotional experiences, separations, conflicts, the way of processing life events, bereavements, dysfunctional communication styles, and conflictual family relationships (especially mother-child).

All these elements go to organise the person’s way of responding to life events.

The vulnerability-stress model in schizophrenia: development, predisposition and vulnerability

In this model, we see not direct causality, but predisposition and triggering factors.

Assuming that mental suffering does not have unambiguous, immutable causes that are valid always and everywhere even for the same person, the uniqueness of the human experience together with risk and protective factors is fundamental.

There are certain triggering factors for the onset or episode of schizophrenia such as drug/pharmaceutical use, stressful life events or a stressful family environment.

During the period of the illness, its course, prognosis and outcome are highly dependent on certain factors such as stigma and social isolation, psychiatric rehabilitation and social role and institutional care models.

An integrated approach to schizophrenia is essential: pharmacological, psychotherapeutic and psycho-educational rehabilitation in which causes and symptoms must be explained, signs of the disorder must be interpreted and the disorder must be understood.

As Jaspers said, “Psychic suffering, unlike objectifiable phenomena that can be both interpreted and explained, can only be understood through empathy.”