Conceptualising paranoia in ASD: A systematic review and development of a theoretical framework

Highlights

• Psychosocial factors may render individuals with ASD vulnerable to developing paranoia.

• Seven cross-sectional studies have examined paranoia in ASD.

• Levels of paranoia are higher in ASD, compared to typically-developing samples.

• ASD traits and neuropsychological functioning may precipitate and perpetuate paranoia.

• A framework outlining causal and maintaining factors for paranoia in ASD is proposed.

Abstract

Paranoia, unfounded ideation that others deliberately intend harm, has predominately been studied in schizophrenia. Increasingly, it is recognised that there is a spectrum of severity of excessive mistrust across the general population. Relatively little is known about paranoia in individuals with autism spectrum disorders (ASD), but rates could be expected to be higher given both difficulties in understanding others’ mental states and frequent experiences of negative social interactions. A systematic search of English-language peer-reviewed publications was undertaken to synthesise empirical research about paranoia in ASD. Seven studies, comprising a total of 180 ASD participants, met the inclusion criteria. All the studies were cross-sectional, thereby limiting causal interpretations. Individuals with ASD were consistently found to have higher levels of paranoia compared to non-clinical controls, and lower levels than individuals with current psychotic experiences manifesting in the context of schizophrenia. Furthermore, the initial evidence indicates that paranoia in ASD may be linked with theory of mind performance, negative affect, and jumping to conclusions, but not to attributional style. As in typically-developing populations, causal and maintaining mechanisms for paranoia in ASD, against a background of genetic and environmental risk, most likely include cognitive and affective processes interacting with social factors. We hypothesise, however, that core ASD characteristics and associated neurocognitive impairments also serve to precipitate and perpetuate paranoia. A framework to guide further investigation is outlined.

Introduction

Autism spectrum disorders (ASD) are childhood onset, behaviourally defined, neurodevelopmental conditions. Core ASD characteristics include socio-communication impairments, adherence to non-functional rituals and routines, and engagement in a narrow repertoire of interests and activities (APA, 2014, WHO, 1992). ASD prevalence rates are reported to just exceed 1% of the population (Brugha et al., 2011), however given significant clinical heterogeneity, and potential sex differences in symptom profiles (Van Wijngaarden-Cremers et al., 2014), it is conceivable that rates are underestimated (NICE, 2011, NICE, 2012).

Although diagnostic overshadowing may mar a full assessment of psychopathology, studies consistently indicate that individuals with ASD are highly likely to experience psychiatric co-morbidities (Joshi et al., 2013, Russell et al., 2015, Simonoff et al., 2008), including anxiety disorders (White, Oswald, Olendick & Scahill, 2009), obsessive compulsive disorder (OCD) (Cadman et al., 2015), low mood and depression (Ghaziuddin, Ghaziuddin & Greden, 2002), and psychosis (Chisholm, Lin, Abu-Akel & Wood, 2015). Similarly, transdiagnostic characteristics – i.e. symptoms which can manifest across a range of psychiatric disorders – occur commonly. Such characteristics can include problems with eating and ‘food selectivity’ (Marí-Bauset, Zazpe, Mari-Sanchis, Llopis-González & Morales-Suáres-Varella, 2014), sleep disturbance (Elrod and Hood, 2015), emotion dysregulation (Weiss, 2014), and paranoia (Blackshaw, Kinderman, Hare & Hatton, 2001).

Recent research indicates that paranoia exists on a spectrum of severity in the general population (Freeman et al., 2005), similar to the profile of common mental health problems such as anxiety and depression (Plomin, Haworth & David, 2009). Paranoia comprises ideas of reference and persecution. The defining type of cognition is persecutory ideation, unfounded ideas that others deliberately intend to harm the person. It is unsurprising that there is a paranoia spectrum in the general population: every day, people make decisions about whether to trust or mistrust, but accurately judging the intentions of others is difficult. Many people have a few paranoid thoughts; a few people have many. One of the clearest demonstrations of this is that a significant minority of the non-clinical general population can have paranoid thoughts about neutral computer characters in immersive virtual reality social situations (Freeman et al., 2008). Paranoia is associated with youth, poverty, isolation, stress, and a range of mental health disorders (Freeman et al., 2011), although the direction of these associations is yet to be definitively established. It is also linked with a range of adverse life experiences (e.g. Bentall, Wickham, Shevlin, & Varese, 2012). Detailed analysis of data from a nationally representative population (N = 8580) indicated that there is a single paranoia dimension, with ideas of persecution building on ideas of reference, which build on mistrust and interpersonal sensitivity (Bebbington et al., 2013). This notion of paranoia building on common concerns about the self in regard to interpersonal relationships is captured in the conceptualisation of a paranoia hierarchy (see Fig. 1) (Freeman et al., 2005). The severity of paranoia varies in content, degree to which concerns are believed, and levels of distress and impairment. At the severe end are persecutory delusions, commonly seen in people who have psychosis or schizophrenia. The presence of persecutory delusions in those diagnosed with non-affective psychosis has led to paranoia predominately being studied in this patient population. However, paranoia is also associated with a range of other mental health disorders including social phobia (Schutters et al., 2012), post traumatic stress disorder (PTSD) (Freeman et al., 2013), depression (Wigman et al., 2012), and bipolar disorder (Goodwin & Jamison, 1990).

The contribution of genetic and environmental causes to the occurrence of paranoia has been examined in one large classical twin design study (Zavos et al., 2014), whereby paranoia was assessed dimensionally in five thousand adolescent twin pairs; it was found that the contribution of genes and environment was approximately equal. Several psychological mechanisms have been hypothesised to precipitate and perpetuate paranoia (Frith, 1992; Bentall, Corcoran, Howard, Blackwood & Kinderman, 2001; Freeman & Garety, 2014). Since almost by definition mental states are being misread in paranoia, theory of mind impairments have been proposed as a cause (Frith, 1992). Similarly, the explanation of events in terms of malevolent others has implicated a generalised externalising and personalising attributional style linked to unstable and negative self-views (Bentall et al., 2001). Another view is that at the centre of paranoia are ideas about threat, linked to anxiety and depression, negative self-beliefs (including interpersonal sensitivity), and adverse life experiences (Freeman & Garety, 2014). Reasoning biases, such as ‘jumping to conclusions’ (reduced data-gathering), have also been considered a contributory causal factor to the levels of conviction and failure to consider alternative explanations seen in paranoia (Garety et al., 2015).

Enhancing understanding of paranoia in ASD is important for several reasons. Our view is that it is theoretically plausible that this clinical population are at an increased risk of developing paranoid ideation. This increased risk may stem, in part, from the social consequences of having ASD. For example, individuals who have ASD desire friendships and intimate relationships, yet they are often rebuffed, and are prone to being bullied and victimised (Schroeder, Cappadocia, Bebko, Pepler & Weiss, 2014); experiences which can exacerbate social withdrawal, augment social-evaluative concerns, and encourage negative beliefs about the self and others (e.g. Gracie et al., 2007), all of which can serve as risk factors for paranoia. But it may also be that neurocognitive processes commonly experienced by individuals with ASD enhance the likelihood of paranoia. For example, difficulties in understanding others’ intentions (Baron-Cohen, Wheelwright, Hill, Raste & Plumb, 2001), a tendency for being detail-focused (commonly referred to as weak central coherence; Happé & Frith, 2006), and problems with cognitive flexibility (Wilson et al., 2014) may render individuals with ASD vulnerable to information or interpretation biases, thereby encouraging the negative misinterpretation of others’ actions, which can also serve as risk factors.

In summary, although paranoia may well co-occur with ASD, it is unclear whether rates and levels are comparable to those reported for typically-developing clinical and non-clinical populations. Also, it is uncertain whether there is a degree of ASD-specificity to paranoia, i.e. whether core ASD or associated characteristics serve to precipitate or maintain paranoid features. In the typically-developing population, there is increasing evidence to suggest that timely assessment and psychological interventions (specifically cognitive behaviour therapy (CBT)) can reduce paranoia, associated distress, and secondary symptoms (e.g. Freeman et al., 2015). Whether this is also the case for the ASD population warrants consideration. The aims of this review were threefold: (1) to synthesise empirical data about ASD and paranoia; (2) to propose a conceptual framework outlining mechanisms potentially contributing to the development and maintenance of paranoia; and (3) to highlight implications for clinical practice and research.