To what extent do studies of paranoia in the non-clinical population inform psychological interventions for psychosis?

Introduction

Research into paranoia in non-clinical populations has enriched our understanding of this phenomenon and informed psychological interventions for psychosis. Paranoia is defined as an interpersonal experience: a fear that others intend to cause you physical, psychological or social harm (Freeman & Garety, 2000; Freeman, Pugh et al., 2008). Within this essay the term ‘psychosis’ refers to a complex concept, including hallucinations, voice hearing and delusions, accompanied by a negative impact on social functioning (Fowler, Garety & Kuipers, 1995; Morrison, Renton, Dunn, Williams, & Bentall, 2004). Persecutory delusions represent the severe end of the paranoia continuum in the general population and are often an experience of psychosis (Freeman, 2006). Delusions are beliefs that are “implausible, unfounded, strongly held, not shared by others, distressing and preoccupying” (Freeman, 2007, p. 426).

This essay aims to consider the extent to which studies of paranoia in the non-clinical population have informed psychological interventions for psychosis, particularly focusing on Cognitive Behavioural Therapy (CBT). Mindfulness based approaches and Acceptance and Commitment Therapy (ACT) will also briefly be considered (Gaudiano, 2015). Studies of paranoia in the non-clinical population may also have informed other psychological interventions, such as family interventions (Haddock & Spaulding, 2013; Pharoah, Rathbone, Mari, & Streiner, 2003); computer avatar interventions (Leff, Williams, Huckvale, Arbuthnot, & Leff, 2014) and interventions developed from user-led movements such as the ‘hearing voices movement’ (Longden, Corstens, Escher & Romme, 2012). Due to the limited scope of this essay these interventions and their links to studies of paranoia in the non-clinical population will not be examined.

Paranoia in the Non-clinical Population

Why Study Paranoia?

Paranoia is associated with reduced social functioning, suicidal ideation, greater use of psychiatric medication and increased use of mental health services (Freeman et al., 2011). Therefore, the experience of paranoia has wide implications for health, wellbeing and social functioning (Freeman et al., 2011). Within the literature the ‘non-clinical population’ refers to people who have not received a psychiatric diagnosis (Freeman, 2006).

The Continuum

Historically, psychosis has been viewed as distinctly different to ‘normal’ experiences (Morrison et al., 2004). However, paranoid beliefs in the general population have a higher prevalence than psychotic disorders, suggesting psychosis exists on a continuum, with a distribution in the general population (Bentall, 1994; Stefanis et al., 2002; Strauss, 1969, cited in Van Os, Hanssen, Bijl, & Ravelli, 2000). The continuum idea is fundamental to understanding clinical experiences of psychosis as it implies delusions are not qualitatively different from other beliefs (Freeman, 2007; Johns & Van Os, 2001).

Prevalence

Paranoia has been found in the non-clinical adult population (Scott, Chant, Andrews & McGrath, 2006). Freeman et al. (2005) found over half the participants in a non-clinical sample endorsed ‘needing to be on guard against others’ during a one-week period and 10-30% had persecutory thoughts, ranging from mild to severe. Perceived lack of control over thoughts was associated with a higher occurrence of thoughts, and beliefs held with more conviction were associated with greater distress (Freeman et al., 2005). Other research has suggested the distribution of paranoia in the general population fits an exponential curve, with ‘most people having few paranoid thoughts and few people having many’ (Bebbington et al., 2013, p. 419). Johns et al. (2004) surveyed over 8000 people and found 20% thought people were against them and 10% thought people had deliberately acted to harm them.

Paranoia has been found in the older adult population (Forsell & Henderson et al., 1998; Ostling & Skoog, 2002) and childhood and adolescence (Laurens, Hobbs, Sunderland, Green, & Mould, 2012; Wigman et al., 2011). Up to 18.2% of a sample of Chinese undergraduates reported paranoid ideation at least once a week (Chan et al., 2011). Wong, Freeman and Hughes (2014) found ‘mistrustful’ children in the UK and Hong Kong showed higher levels of anxiety, low self-esteem and aggression. Delusions have also been discovered in the non-clinical population (Eaton, Romanoski, Anthony, & Nestadt, 1991; Freeman, 2006; Peters, Joseph & Garety, 1991). These studies suggest experiences of paranoia occur across ages and cultures.

Limitations

Despite evidence of paranoia in the non-clinical population, self-select survey methods may inadvertently recruit


participants experiencing psychological difficulties (Freeman et al., 2005) or participants experiencing psychological difficulties may be less likely to respond (Van Os & Verdoux, 2003). Therefore, generalisations from prevalence studies should be tentative. Mullen (2003) claimed the language used by Peters et al. (1991) meant delusions were ‘toned down’ so the conclusion that delusions are on a continuum with ‘normal beliefs’ was questionable (p. 507). Freeman et al. (2005) highlight that many prevalence studies only report whether an experience is present or not, therefore no causal inferences can be made. Further, some “paranoid” thoughts may be based in reality so may not truly be examples of paranoia (Freeman et al., 2005; Mullen, 2003).

Experimental Studies

To overcome difficulties with self-select survey methods, experimental studies have been undertaken with non-clinical populations. Ellett and Chadwick (2007) used a task with self-awareness and failure as variables. High levels of self-awareness in addition to ambiguous feedback or explicit failure were associated with higher levels of paranoia. The researchers proposed paranoid thoughts increased with greater self-focused attention, in line with the ‘self-as-target bias’, which claims people who focus on themselves assume others are doing the same (Ellett & Chadwick, 2007;


Fenigstein & Vanable, 1992). This research supported the idea of the self-serving bias, which states paranoia has a self-protective function as people attribute negative outcomes to external causes (Bentall, 1994; Bentall et al., 2009). This idea was supported when people with high self-awareness completed a prior self-affirmation task and their experience of paranoia reduced (Kingston & Ellett, 2014).

Virtual Reality

Virtual reality research is beneficial as ‘real-time’ experiences of paranoia can be measured, and the characters behave in ways deemed to be neutral by consensus, meaning paranoid thoughts are more likely to be unfounded (Freeman, Gittins et al., 2008; Freeman, Pugh et al., 2008). Freeman, Gittins et al. (2008) created a virtual experience of an underground train to capture misinterpretations of facial expressions and concluded state paranoia could be triggered in environments that lacked objective threat in the non-clinical population. Using virtual reality, researchers have suggested a connection between paranoia in the non-clinical population and persecutory delusions within psychosis due to interpersonal sensitivity, anxiety and traumatic events predicting paranoia in both populations (Freeman et al., 2003; Freeman, Pugh et al., 2008; Freeman, Pugh, Vorontsova, Antley, & Slater, 2010).

Prisoner’s Dilemma Game

In the Prisoner’s Dilemma Game (PDG) two players are forced to choose between collaborating or competing against each other (Ellett, Allen-Crooks, Stevens, Wildschut, & Chadwick, 2013). If both players choose to compete the potential outcomes are worse than if they choose to collaborate whereas, if one chooses to compete and the other chooses to work collaboratively, the one who decided to compete gains greater outcomes (Ellett et al., 2013, Freeman & Garety, 2000). The PDG is interpersonal, concerned with issues of threat and trust, and is ambiguous, therefore useful for studying paranoia (Ellett et al 2013). Using the PDG, Ellett et al. (2013) found people with higher state paranoia were more likely to make a competitive choice when they believed they were playing against another person, highlighting the interpersonal nature of paranoia.

Links to Psychosis

To consider the extent to which studies of paranoia in the non-clinical population inform psychological interventions for psychosis, the links between non-clinical and clinical levels of paranoia need to be considered. Dominguez (2011) discovered that the more ‘psychosis-like’ experiences persisted over time during adolescence, the more likely it was those individuals would be diagnosed with clinical psychosis later in life. Other studies have found experiences of hallucinations and delusions in adolescence predicted later development of psychosis (Linscott & Van Os, 2013; Poulton et al., 2000).

Despite some limitations, the body of research described above has greatly influenced our understanding of psychosis from a psychological perspective and contributed to psychosis being conceptualised within a cognitive model.

Cognitive Model of Psychosis

The cognitive model is based on the premise that interpretations of events, rather than events themselves, contribute to emotional distress (Beck, Rush, Shaw & Emery, 1979). This has been applied to the conceptualisation of psychosis where it is thought that interpretations of experiences of psychosis determine whether an individual becomes distressed by their experience (Chadwick, 2006; Garety, Kuipers, Fowler, Freeman, & Bebbington, 2001; Morrison et al., 2001; Morrison, Wells & Nothard, 2000, 2002).

Studies of paranoia in the non-clinical population have informed this cognitive conceptualisation of psychosis. For example, Freeman, Gittins et al. (2008) explain that, in the context of anxiety, perceptual abnormalities, for example innocuous bodily sensations, can trigger paranoia. The non-clinical literature has also elucidated factors making the development of psychosis more likely. Positive beliefs about paranoia (for example, beliefs about experiences adding meaning to one’s life) were found to predict vulnerability to hallucinations (Morrison et al., 2005; 2001; Morrison, Wells, & Nothard, 2000, 2002). The addition of negative beliefs, such as beliefs about experiences being uncontrollable, determine whether someone feels distressed and seeks help, thus reaching a ‘clinical’ level of psychosis (Morrison, Wells & Nothard, 2000; 2002).

The cognitive model for psychosis also suggests distress is maintained by unhelpful ways of thinking and behaving, such that alternative explanations for unusual experiences are not considered (Bucci & Tarrier, 2016, Chadwick, 2006).

CBT Interventions for Psychosis

Together with behavioural theories, the cognitive model forms the basis for CBT for psychosis, which has been shown to be an effective psychological intervention with moderate effect sizes (Steel, Tarrier, Stahl, & Wykes, 2012; Zimmermann, Favrod, Trieu, & Pomini, 2005). The National Institute for Health and Care Excellence [NICE] (2014) recommends at least sixteen sessions of CBT delivered on a one to one basis for first episode psychosis and severe and enduring psychosis, alongside medication. Various elements of CBT for psychosis will be explored next, with links to the literature considered.

Normalising

Individuals experiencing long term psychosis are likely to have a diagnosis of ‘Schizophrenia’, which can be stigmatising (Corrigan, Watson, & Barr, 2006). Collaboratively discussing new ways of understanding one’s “disorder” can serve to reduce feelings of self-blame and stigma (


Baba et al., 2017; Chadwick, Trower & Birchwood, 1996). Within the early stages of CBT the prevalence of unusual experiences, for example paranoia, in the non-clinical population is explored in order to modify unhelpful interpretations about the meaning of unusual experiences (Turkington, Kingdon & Weiden, 2006). Normalising has been shown to reduce negative beliefs about paranoia, and distress (Wood, Birtel, Alsawy, Pyle, & Morrison, 2014).

Within non-clinical populations traumatic events have been linked with paranoia (Freeman et al., 2010). Within CBT, stress-vulnerability models can be explored to help people consider the interaction of personal vulnerability factors, coping skills, stressful life events and environmental protective factors (


Nuechterlain, Parasuraman & Jiang, 1983, Chadwick, 2006). An individualised formulation can help people be less self-blaming if they realise they had a pre-existing vulnerability to psychosis and then experienced stressful life events beyond their control (


Chadwick, 2006; Dudley, Kuyken and Padesky, 2011). These ideas suggest studies into paranoia in the non-clinical population have been utilised in psychological interventions for psychosis.

Beliefs about Experiences

Research with a non-clinical population has shown people report differences in degrees of conviction in paranoid thoughts, and levels of preoccupation and distress associated with their thoughts (Ellett, Lopes & Chadwick, 2003; Freeman et al., 2005; Morrison et al., 2005). It is therefore useful to assess these factors within CBT, along with individual beliefs about the identity, perceived power and intent of voices, and the control the person feels they have over their voices (Chadwick et al., 1996, Fowler et al, 1995; Steel, 2008).

To challenge beliefs about voices being uncontrollable, CBT involves triggering voices in session then stopping them using distraction, for example by reading aloud, or gaining a sense of control over voices by suggesting they fade away (Chadwick & Birchwood 1994; Fowler & Morley, 1989). Cognitive therapy has been shown to reduce the degree of conviction in the power and superiority of voices, and reduce compliance behaviour in people experiencing command hallucinations (Trower et al., 2004). If someone holds positive beliefs about paranoia, for example that it helps them stay safe, these beliefs can be explored and re-evaluated within CBT (Murphy et al., 2017). It could be argued that non-clinical research has highlighted the role of beliefs about experiences in the development and maintenance of paranoia and this has strengthened the idea that beliefs about experiences need to be targeted in CBT.

Reasoning Biases

Paranoia in the general population is associated with reasoning biases, particularly jumping to conclusions, and reduced analytic reasoning (Freeman, Evans & Lister., 2012; Freeman, Gittins et al., 2008; So et al., 2012). In a comparison between people with high and low paranoia in a non-clinical sample, the high paranoia group perceived more hostility and blame in an ambiguous social situation (Combs et al., 2013). Similar reasoning biases have been found in the clinical population as people with persecutory delusions use rational reasoning styles less frequently (Freeman, Lister & Evans, 2014). Reasoning biases contribute to ‘belief inflexibility’, which is associated with higher conviction in delusions (Freeman et al., 2004; Garety et al., 2005).

CBT for psychosis involves monitoring thoughts, feelings and behaviours to establish whether people interpret neutral events in negative ways, then enabling people to consider alternative, less threatening, explanations (Fowler et al., 1995; Morrison et al., 2004).

Within CBT for psychosis, one approach to working with delusions involves helping people recognise their delusion is a belief or interpretation, using the Antecedents-Beliefs-Consequences model (Chadwick et al., 1996, p. 47). Subsequently, people are encouraged to discover evidence that does not fit with their delusion or, if that proves difficult, to consider how hypothetical contradictions would impact on their beliefs (Chadwick et al., 1996; p. 119).

Researchers delivered a brief reasoning intervention to people experiencing delusions and found reductions in paranoia, reduced use of the ‘jumping to conclusions’ reasoning bias and increased belief flexibility (Garety et al., 2015). It could be argued that studies of paranoia in the non-clinical population helped informed these interventions as they challenged the idea that delusions were qualitatively different beliefs, allowing them to be targeted within CBT (Morrison et al., 2004).

Negative Self-Evaluations

Ellett et al., (2003) suggest low self-esteem is associated with higher paranoid ideation in the non-clinical population. Freeman and Garety (2014) explain negative views of the self can lead to feeling different, inferior and vulnerable, and paranoia is more likely to develop when someone perceives themselves as vulnerable (p. 1181). There have been similar findings with clinical samples, suggesting negative views of the self are influential in maintaining psychosis (Bentall et al., 2009; Garety & Freeman, 2013; Tiernan, Tracey & Shannon, 2014). Fowler et al. (2012) suggested the link between depressed mood and paranoia was mediated by negative views of self and others, low self-esteem and self-criticism. However, they acknowledge that, due to the longitudinal design, the links are only correlational and suggest an experimental design would help control for confounding variables. Another study with a clinical population displaying early signs of psychosis found the more someone held negative beliefs about the self the more they believed they ‘deserved’ persecution (Morrison et al., 2015).

In terms of intervention, Chadwick (2003) outlines the ‘two chairs method’ where people are encouraged to experience their usual negative self-view then physically move seats within session to experience an alternative positive self-view. People are then encouraged to notice experiences that do not fit with their negative self-view (Chadwick, 2003). A life review can help reframe misinterpretations of adverse life events that may have contributed to a negative self-view (Curr & McNulty, 2006). If someone has experienced multiple episodes of psychosis and been labelled as a ‘patient’, helping them view themselves as ‘survivor’ instead of ‘victim’ may be helpful (Curr & McNulty, 2006). Addressing negative thoughts about the self has also been shown to help people overcome avoidance of busy places and this is increasingly a focus in CBT for psychosis (Freeman et el., 2014; Freeman, Waller et al., 2015). In summary, interventions targeting self-esteem appear to be influenced by studies of paranoia in the non-clinical population. CBT also focuses on helping people make changes to the behaviours maintaining their difficulties (


Tully, Wells & Morrison, 2017; Westbrook, Kennerley & Kirk, 2007).

Behavioural Experiments

It has been found that people in the non-clinical population who attach meaning to their paranoid thoughts feel more distressed and act accordingly, for example by using avoidance (Ellett et al., 2003; Freeman et al., 2005; Freeman et el., 2014). Avoidance prevents the disconfirmation of beliefs and is a common maintenance factor in anxiety disorders (Clark & Wells, 1995; Westbrook et al., 2007). Within the clinical population, people experiencing psychosis have been found to use avoidance as a coping strategy (Freeman et al., 2014, Tully et al., 2017). Within interventions for psychosis, overcoming avoidance is a target for change (Van der Gaag, Nieman, & Van den Berg, 2013). Behavioural experiments are used to help people overcome avoidance and test out beliefs about voices (Chadwick, 2006; Menon et al., 2015). These behavioural approaches demonstrate how research into paranoia in the non-clinical population has been used to support the development of interventions for psychosis.

Rumination and Worry

Rumination has been found to maintain paranoia (Martinelli, Cavanagh & Dudley, 2013). One study induced paranoia in non-clinical participants and found evidence that ruminative self-focus maintained paranoia whereas mindful self-focus reduced levels of paranoia (McKie, Askew & Dudley, 2017). In a non-clinical population, Freeman, Pugh et al. (2008) identified worry as important in the development of paranoia. A longitudinal study showed the emergence of new paranoid thoughts was predicted by the presence of worry in both non-clinical and clinical populations (Freeman et al., 2012). This suggests non-clinical research informs areas for research with clinical populations. In a subsequent clinical trial a six-session worry reduction intervention plus standard care was compared with standard care alone and the addition of the worry reduction intervention led to significant reductions in worry and delusions (Freeman, Dunn et al., 2015). Changes in worry mediated most of the change in delusions, suggesting worry is an important area to target in psychological interventions for psychosis (Freeman, Dunn et al., 2015).

Mindfulness and ACT

Research into non-clinical paranoia has also informed the development of ‘third wave’ approaches for psychosis, such as mindfulness and ACT (Kabat-Zinn, 2003; Sugiura, 2004). These approaches encourage people to relate to experiences of voices and delusions in a different way, for example by increasing awareness of the experiences then fostering distance from them, known as ‘decentring’ (


Lau, Bishop & Segal et al., 2006). This reduces distress as people learn their experiences are not reflections of themselves (Chadwick, Barnbrook & Newman-Taylor, 2017). During interventions, people experiencing voices or delusions are encouraged to practice skills to help them view their experiences as passing events and foster acceptance of unusual experiences (Chadwick et al., 2007; Gaudiano, 2015).

ACT has been found to reduce the believability of thoughts and reduce re-admission to hospital for acute patients experiencing psychosis (Bach & Hayes, 2002; Bach, Gaudiano, Hayes & Herbert, 2013). However, results with medication-resistant psychosis have been mixed: clinically significant improvements in positive symptoms and hallucination distress were shown when ACT was compared with befriending, but befriending led to greater improvements in delusion distress (Shawyer et al, 2017).

Research into paranoia in non-clinical populations has highlighted the role of beliefs and responses to experiences when determining levels of distress (Freeman et al., 2005; Morrison, Wells & Nothard, 2000; 2002). It could therefore be argued that both mindfulness and ACT interventions for psychosis are informed by studies of non-clinical paranoia as they aim to change how one responds to their experiences (Kabat-Zinn, 2003; Lau, Bishop & Segal et al., 2006).

Discussion

Efficacy of CBT

Around fifty percent of people who have completed CBT for psychosis show limited improvement (O’Keeffe, Conway, & McGuire, 2017; Turkington, & McKenna, 2003). One view that may account for why half of people show limited improvement, is the view that delusions are actually distinct from other beliefs and not on a continuum with ‘normal’ experience (Jaspers, 1963, cited in Jones, Delespaul, & Van Os, 2003; Mullen, 2003). If delusions are distinct from other beliefs, this suggests findings from the non-clinical population have limited generalisability to people with psychosis (Mullen, 2003).

Research with Clinical Populations

Many studies informing psychological interventions have used clinical samples of people with ‘chronic treatment-resistant psychosis who have been stabilised on anti-psychotic medication’ (Haddock & Lewis, 2005, p. 697). Studies into non-clinical populations involve participants who have no formal diagnosis, are not prescribed anti-psychotic medication and who are not debilitated by paranoia (Freeman, 2006). It could therefore be argued that psychological interventions for psychosis have been informed by studies into maintenance processes in the clinical population more than studies of paranoia in the non-clinical population and that these populations are very different.

Research into paranoia in the non-clinical population has highlighted important factors involved in the development of clinical paranoia, for example, interpersonal sensitivity and anxiety (Freeman, Pugh et al., 2008). It could therefore be argued that this body of research has informed psychological interventions for people at risk of developing psychosis to a great extent (Morrison et al., 2015). However, with regard to severe and enduring psychosis, studies of paranoia in non-clinical populations may have informed interventions indirectly, for example, by highlighting areas to investigate in clinical populations. These clinical studies have subsequently informed interventions (Freeman, Dunn et al., 2015).

CBT for Anxiety and Depression

Another view is that the continuum idea led to researchers recognising that people with psychosis are no different to people with other disorders, for example, anxiety disorders (Morrison et al., 2004). This meant established CBT models into maintenance factors and their associated interventions were applied to psychosis (Beck et al., 1979; Chadwick et al., 1996; Morrison et al, 2004; Westbrook et al., 2007). On the one hand it could be said that the body of research into CBT for anxiety disorders and depression has greatly informed psychological interventions for psychosis, rather than studies of paranoia in the non-clinical population. It could also be argued that, without the continuum view, these models would not have been applied to psychosis and psychosis may have still been considered ‘untreatable’ (Chadwick et al., 1996; Morrison et al., 2004).

Conclusion

In conclusion, the continuum view of psychosis, derived from studies of paranoia in the non-clinical population, appears to have informed psychological interventions to a great extent, particularly by informing the cognitive model and the development of CBT for psychosis. Studies of paranoia in the non-clinical population have highlighted risk factors for the development of psychosis, for example, interpersonal sensitivity, anxiety and traumatic events (Freeman, Pugh et al., 2008, Freeman et al., 2010). Research into non-clinical paranoia has also informed interventions for psychosis by highlighting areas to focus on during intervention, for example, normalisation, beliefs about experiences, reasoning biases, negative self-evaluations, unhelpful behaviours, rumination and worry. Alternatives to the continuum view, along with other factors that have informed psychological interventions (studies with clinical populations and research into CBT for anxiety disorders) have been considered.

Despite these alternative views, it appears viewing psychosis as an exaggeration of ‘normal’ experience contributed to the realisation that people experiencing psychosis are no different from other people, which challenged the view that psychosis was ‘untreatable’ with psychological interventions. This has contributed to reducing stigma for people with psychosis (Baba et al., 2017). In conclusion, studies of paranoia in the non-clinical population have informed psychological interventions for psychosis to a great extent and in a meaningful way. However, findings show that around fifty percent of people who have completed CBT for psychosis show limited improvement (O’Keeffe, Conway, & McGuire, 2017; Turkington, & McKenna, 2003), suggesting further research into non-clinical and clinical populations is required, in order to improve the efficacy of this psychological intervention for psychosis.

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