**1. Introduction**

Schizophrenia is a type of 'psychosis' which causes individuals to experience distressing symptoms [1] such as the lack of ability to distinguish between reality and one's own thoughts and beliefs [2]. Schizophrenia consists of positive symptoms which are those that are an addition to the individual (i.e. delusions and hallucinations) and negative symptoms which take away something from the individual (i.e. anhedonia and lack of social interest) according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; [3]). The prevalence of schizophrenia in the United Kingdom is 0.7% amongst a population of 74,176 [4]. The prevalence of schizophrenia in the United States of America is 0.5% amongst a population of 10,000,000 [5]. In a multinational study of 52 countries, the

prevalence of schizophrenia is 1.11% amongst a population of 181,445 [6]. This indicates that there is a high prevalence amongst a relatively small proportion of a population, the importance of investigating such individuals as a global concern.

Living with a close relative suffering from a mental illness may cause debilitating negative impacts on that individual such as developing symptoms of schizophrenia or the illness itself [7]. Researchers identified that the closer the relative to the individual with schizophrenia, the greater the incidence of being diagnosed with a psychiatric disorder [8]. Previous research has explored the heritable component of schizophrenia, also considered as the high-risk (HR) perspective in research, whereby the offspring of the individual with schizophrenia are investigated [9]. The genetic risk of developing schizophrenia for relatives of those with schizophrenia is within the range of 60–80% [10]. In addition, it was found that the risk for HR offspring to develop psychotic or other psychiatric conditions ranged between 15 and 40% [11]. Previous studies displaying the risk of developing schizophrenia and other psychiatric disorders identify the relatively high heritability of schizophrenia amongst HR offspring, which further suggests a possible genetic influence of the disorder. This may propose a model indicating the genetic influences of the susceptibility to negative outcomes, such as psychiatric disorders amongst the offspring, thus signifying the importance of investigating such individuals.

Moreover, research has explored the effects of parental schizophrenia on offspring and found that offspring living with one parent diagnosed with schizophrenia has been found to have a 13% risk of developing schizophrenia, in comparison to an increased 45% risk of developing schizophrenia of those with two parents clinically diagnosed [12]. Previous research has also highlighted upon the cumulative incidence across other cultural populations, whereby the cumulative incidence in Denmark for HR offspring was a 16.2% risk of developing schizophrenia [13], 10–15% in Edinburgh [14] and 13.1% in the United States of America [15]. Research also found that HR offspring developed negative symptoms associated with schizophrenia including anhedonia [16]. This builds upon the notion of schizophrenia being highly heritable, thus supporting the idea that there is a strong genetic vulnerability of negative outcomes on the well-being of offspring, such as symptoms of schizophrenia and other psychiatric disorders passed from parent to offspring.

In addition, previous literature has identified an increased risk of HR offspring developing psychiatric conditions other than schizophrenia which include personality disorders [13], thought disorders [17], depression [18] and attention deficit hyperactivity disorder [19]. Previous literature also reports higher comorbidity rates twice that of offspring without a parent with schizophrenia [15], suggesting that parental schizophrenia increases the risk of a dual diagnosis amongst offspring. This signifies the importance of investigating HR offspring, strengthening the idea that schizophrenia amongst parents has a strong genetic influence of negatively impacting well-being.

#### **1.1 Psychosocial aspects**

Furthermore, research has identified the impact of parental schizophrenia on the psychosocial well-being of HR offspring. The term 'psychosocial' impact concerns psychological aspects and the interaction between emotions, behaviours, feelings and social factors, e.g. social functioning [20]. Social factors refer to the way an individual lives different experiences via different attitudes and personalities [20]. Poor social functioning is a hallmark of schizophrenia [21]. The term 'well-being 'concerns an individual's optimal functioning level, physically and psychologically [22]. It also involves having a sense of comfort and happiness in one's own everyday living. This also overlaps with having a good quality of life, whereby an individual has a complete sense of physical and mental well-being. Quality of life differentiates slightly from

**163**

*The Impacts of Parental Schizophrenia on the Psychosocial Well-Being of Offspring:…*

implying a genetic propensity provided by the parent to their offspring.

the development of negative psychosocial impacts on HR offspring.

Moreover, the HR perspective has been investigated in different types of environments in which the offspring is living away from the parent with schizophrenia through carrying out adoption studies. Adoption studies aid in eliminating the environmental impacts of living with a parent suffering from schizophrenia. Parental schizophrenia can result in a distorted environment for the HR offspring resulting in negative outcomes such as schizophrenia and other psychiatric conditions. By conducting adoption studies, this will allow a nature and nurture argument can take place [8]. It was found that adopted children were more likely to

In contrast, research has identified other impacts on HR offspring unrelated to the psychosocial aspects previously stated, which includes poor academic performance [29, 30], working memory deficits [31], high offending rates [32], higher mortality rates [33] and poor self-reported physical health [34]. As much research has focused on aspects unrelated to the psychosocial well-being of HR offspring, it is important to focus on the under-researched aspects of the HR perspective. This further highlights the importance of identifying the underlying mechanisms involved.

As previous research has found schizophrenia to be highly heritable amongst HR offspring [35], this raises questions regarding the underlying mechanisms and processes that make schizophrenia heritable. Studies have explored the neurological pathways amongst those with schizophrenia and have found there to be altered brain connectivity and volumetric brain differences, resulting in symptoms of schizophrenia amongst these individuals [36–38]. It has been found that HR offspring of those with schizophrenia have volumetric deficits in brain connectivity and networks, resulting in abnormal brain functioning and consequently symptoms of schizophrenia [39, 40]. Volumetric brain reductions have also been found amongst HR offspring in the hippocampus, amygdala [41] and the frontal and temporal lobes [42]. These findings indicate the existence of brain abnormalities amongst those with schizophrenia, suggesting that parental schizophrenia negatively impacts HR offspring due to the genetically transmitted brain vulnerability. This also implies that the brain abnormalities are present from birth, and thus, HR studies exploring the developmental trajectories of the illness using longitudinal studies will be able to map out the disorder and biological markers involved. Longitudinal studies can further identify a potential critical period for

well-being, in terms of the individual's perception of their quality of life. Nonetheless, research has been conducted to investigate the social impacts on HR offspring. It was found that HR offspring present themselves as more socially dysfunctional than the control group [23]. Additionally, some research has found further negative impacts on the psychosocial well-being of HR offspring such as decreased quality of life [7], reduced self-esteem [24], inability to express emotions [25], deficits in social competence [26] and higher rates of behavioural issues [27]. It has also been found that poor social functioning predicts the later development of schizophrenia [28], indicating an association between psychosocial aspects and the diagnosis of schizophrenia amongst HR offspring. This suggests that the genetic influence of negative impacts of parental schizophrenia extend to psychosocial functioning which appears to be impaired amongst HR offspring. This identifies that not only is the HR offspring susceptible to psychiatric conditions but also vulnerable to impaired psychosocial functioning,

*DOI: http://dx.doi.org/10.5772/intechopen.91658*

**1.2 Brain abnormalities**

**1.3 Environmental influences**

*The Impacts of Parental Schizophrenia on the Psychosocial Well-Being of Offspring:… DOI: http://dx.doi.org/10.5772/intechopen.91658*

well-being, in terms of the individual's perception of their quality of life. Nonetheless, research has been conducted to investigate the social impacts on HR offspring. It was found that HR offspring present themselves as more socially dysfunctional than the control group [23]. Additionally, some research has found further negative impacts on the psychosocial well-being of HR offspring such as decreased quality of life [7], reduced self-esteem [24], inability to express emotions [25], deficits in social competence [26] and higher rates of behavioural issues [27]. It has also been found that poor social functioning predicts the later development of schizophrenia [28], indicating an association between psychosocial aspects and the diagnosis of schizophrenia amongst HR offspring. This suggests that the genetic influence of negative impacts of parental schizophrenia extend to psychosocial functioning which appears to be impaired amongst HR offspring. This identifies that not only is the HR offspring susceptible to psychiatric conditions but also vulnerable to impaired psychosocial functioning, implying a genetic propensity provided by the parent to their offspring.

In contrast, research has identified other impacts on HR offspring unrelated to the psychosocial aspects previously stated, which includes poor academic performance [29, 30], working memory deficits [31], high offending rates [32], higher mortality rates [33] and poor self-reported physical health [34]. As much research has focused on aspects unrelated to the psychosocial well-being of HR offspring, it is important to focus on the under-researched aspects of the HR perspective. This further highlights the importance of identifying the underlying mechanisms involved.

#### **1.2 Brain abnormalities**

*Quality of Life - Biopsychosocial Perspectives*

prevalence of schizophrenia is 1.11% amongst a population of 181,445 [6]. This indicates that there is a high prevalence amongst a relatively small proportion of a population, the importance of investigating such individuals as a global concern. Living with a close relative suffering from a mental illness may cause debilitating negative impacts on that individual such as developing symptoms of schizophrenia or the illness itself [7]. Researchers identified that the closer the relative to the individual with schizophrenia, the greater the incidence of being diagnosed with a psychiatric disorder [8]. Previous research has explored the heritable component of schizophrenia, also considered as the high-risk (HR) perspective in research, whereby the offspring of the individual with schizophrenia are investigated [9]. The genetic risk of developing schizophrenia for relatives of those with schizophrenia is within the range of 60–80% [10]. In addition, it was found that the risk for HR offspring to develop psychotic or other psychiatric conditions ranged between 15 and 40% [11]. Previous studies displaying the risk of developing schizophrenia and other psychiatric disorders identify the relatively high heritability of schizophrenia amongst HR offspring, which further suggests a possible genetic influence of the disorder. This may propose a model indicating the genetic influences of the susceptibility to negative outcomes, such as psychiatric disorders amongst the offspring,

thus signifying the importance of investigating such individuals.

Moreover, research has explored the effects of parental schizophrenia on offspring and found that offspring living with one parent diagnosed with schizophrenia has been found to have a 13% risk of developing schizophrenia, in comparison to an increased 45% risk of developing schizophrenia of those with two parents clinically diagnosed [12]. Previous research has also highlighted upon the cumulative incidence across other cultural populations, whereby the cumulative incidence in Denmark for HR offspring was a 16.2% risk of developing schizophrenia [13], 10–15% in Edinburgh [14] and 13.1% in the United States of America [15]. Research also found that HR offspring developed negative symptoms associated with schizophrenia including anhedonia [16]. This builds upon the notion of schizophrenia being highly heritable, thus supporting the idea that there is a strong genetic vulnerability of negative outcomes on the well-being of offspring, such as symptoms of schizophrenia and other psychiatric disorders passed from parent to offspring. In addition, previous literature has identified an increased risk of HR offspring developing psychiatric conditions other than schizophrenia which include personality disorders [13], thought disorders [17], depression [18] and attention deficit hyperactivity disorder [19]. Previous literature also reports higher comorbidity rates twice that of offspring without a parent with schizophrenia [15], suggesting that parental schizophrenia increases the risk of a dual diagnosis amongst offspring. This signifies the importance of investigating HR offspring, strengthening the idea that schizophrenia amongst parents has a strong genetic influence of negatively impacting well-being.

Furthermore, research has identified the impact of parental schizophrenia on the psychosocial well-being of HR offspring. The term 'psychosocial' impact concerns psychological aspects and the interaction between emotions, behaviours, feelings and social factors, e.g. social functioning [20]. Social factors refer to the way an individual lives different experiences via different attitudes and personalities [20]. Poor social functioning is a hallmark of schizophrenia [21]. The term 'well-being 'concerns an individual's optimal functioning level, physically and psychologically [22]. It also involves having a sense of comfort and happiness in one's own everyday living. This also overlaps with having a good quality of life, whereby an individual has a complete sense of physical and mental well-being. Quality of life differentiates slightly from

**162**

**1.1 Psychosocial aspects**

As previous research has found schizophrenia to be highly heritable amongst HR offspring [35], this raises questions regarding the underlying mechanisms and processes that make schizophrenia heritable. Studies have explored the neurological pathways amongst those with schizophrenia and have found there to be altered brain connectivity and volumetric brain differences, resulting in symptoms of schizophrenia amongst these individuals [36–38]. It has been found that HR offspring of those with schizophrenia have volumetric deficits in brain connectivity and networks, resulting in abnormal brain functioning and consequently symptoms of schizophrenia [39, 40]. Volumetric brain reductions have also been found amongst HR offspring in the hippocampus, amygdala [41] and the frontal and temporal lobes [42]. These findings indicate the existence of brain abnormalities amongst those with schizophrenia, suggesting that parental schizophrenia negatively impacts HR offspring due to the genetically transmitted brain vulnerability. This also implies that the brain abnormalities are present from birth, and thus, HR studies exploring the developmental trajectories of the illness using longitudinal studies will be able to map out the disorder and biological markers involved. Longitudinal studies can further identify a potential critical period for the development of negative psychosocial impacts on HR offspring.

#### **1.3 Environmental influences**

Moreover, the HR perspective has been investigated in different types of environments in which the offspring is living away from the parent with schizophrenia through carrying out adoption studies. Adoption studies aid in eliminating the environmental impacts of living with a parent suffering from schizophrenia. Parental schizophrenia can result in a distorted environment for the HR offspring resulting in negative outcomes such as schizophrenia and other psychiatric conditions. By conducting adoption studies, this will allow a nature and nurture argument can take place [8]. It was found that adopted children were more likely to

develop schizophrenia, if they had a biological parent suffering from schizophrenia, in comparison to those that did not [43]. This supports the idea that schizophrenia is genetically transmitted strengthening the notion that neurological pathways are distorted amongst HR offspring as with the parents. Therefore, this indicates that not only is there a genetic influence but there is also an environmental influence, suggesting a gene-environment interaction arising from the development of negative impacts on the psychosocial well-being of offspring.

Moreover, another method to explore the HR perspective is by exploring HR offspring that are twins in studies. This allows an enhanced perspective regarding genetic and environmental influences to be considered. Twin and adoption studies found that the risk of HR individuals developing schizophrenia was 9% for siblings, 13% for HR offspring with one parent suffering from schizophrenia and 46% for HR offspring with two parents [44]. As there was found to be a genetic risk amongst twin and adoption studies for HR offspring, these findings also display an environmental influence as the genetic risk is not 100%. Therefore, there must be other factors within the offspring's environment involved in the development of schizophrenia suggesting a possible diathesis-stress model of schizophrenia. The diathesis-stress model is the idea that mental illnesses are developed from a genetic or biological component of a particular illness (i.e. schizophrenia) which is combined with stressful environmental factors, which all influence the vulnerability for a mental illness. In this particular instance, this involves negative environmental factors interacting with the genetic vulnerability for schizophrenia amongst HR offspring, resulting in an elevation of risk and heritability in the development of negative impacts on the psychosocial well-being of offspring [45].

Furthermore, extending beyond the idea that environmental factors elevate the risk for developing psychological difficulties, much research has been conducted within this area exploring other factors. This includes factors such as unemployment and socio-economic disadvantage [12], childhood sexual abuse [34], marital conflict amongst the parents of HR offspring [46], poor upbringing due to hospitalisation of parents or neglect [47], inadequate parental care [48] and other stressful life events such as loss and traumatic events [49, 50]. Stressful life events have the potential to trigger the onset of symptoms of schizophrenia and other disorders [51]. Such studies, highlighting upon the environmental factors involved in the developmental trajectory of schizophrenia, strengthen the proposed diathesisstress model explaining why negative outcomes occur in HR offspring. This is by demonstrating that the environment acts as a stressor in increasing the genetic risk and heritability of schizophrenia and symptoms involved.

#### **1.4 The current review**

This systematic review is exploring the following psychosocial aspects influencing the well-being of HR offspring: social skills and functioning, self-concept, quality of life, employment situation and the prevalence of disorders and emotional/behavioural symptoms. Regarding the term 'social skills and functioning', this includes self-esteem and self-concept. Due to the limited amount of research within these domains, it would be worthy to investigate and obtain insightful formulations.

A review is needed with recent studies that build upon the HR research but also focus on the psychosocial impacts signifying a diathesis-stress model, linking parental schizophrenia and negative impacts on HR offspring. This is because awareness can be raised and possible support can be given to HR offspring as a preventative technique regarding the prevention of negative psychosocial impacts. Current interventions focus on aiding the parent with schizophrenia but should also be put in place to aid the HR offspring [12].

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**Figure 1.**

*Inclusion and exclusion summary of PECO.*

*The Impacts of Parental Schizophrenia on the Psychosocial Well-Being of Offspring:…*

To identify the impact of parental schizophrenia on the psychosocial well-being

To explore the likelihood that HR offspring will develop schizophrenia or other

This paper is a systematic review compiled of cross-sectional and longitudinal studies. The findings of the articles were presented into a narrative synthesis. An extensive search strategy was adopted to identify relevant papers using applicable terms and synonyms. The process involved a critical evaluation of relevant papers and steps to be followed such as searching databases according to the inclusion/ exclusion criterion, data extraction and quality assessments of relevant papers. An electronic database named PROSPERO was also searched to identify pre-existing systematic reviews within the chosen topic to minimise any potential bias and identify the 'grey literature'. The selection strategy of papers was divided into categories comprising of population, exposure, comparator and outcome(s),

The articles retrieved from the databases in accordance to the selection criteria were imported into EndNote, an electronic reference manager. Duplicate articles were also deleted and were then examined to be included and excluded in accordance to the stated criterion for PECO. Those that were excluded were justified with

*DOI: http://dx.doi.org/10.5772/intechopen.91658*

*1.4.1 Aims*

of HR offspring.

**2. Methods**

shown in **Figure 1**.

**2.1 Study selection**

psychiatric conditions.

*The Impacts of Parental Schizophrenia on the Psychosocial Well-Being of Offspring:… DOI: http://dx.doi.org/10.5772/intechopen.91658*
