Table 1.
Summary of included studies
| Source | Design | Sample characteristics | Measures | Attachment subtypes | Key findings | |
|---|---|---|---|---|---|---|
| Attachment | Paranoia | |||||
| Dozier and Lee (1995) USA | Cross‐sectional | Paranoid schizophrenia (24), undifferentiated schizophrenia (23), bipolar affective disorder (27), panic disorder (1), conversion disorder (1) (n = 76). 45 male | AAI | BSI | Secure versus insecure prototype | Individuals who relied on more hyperactivating (anxious) reported higher symptoms than those with deactivating (avoidant) (specific statistic not reported). Avoidant attachment (deactivating) reported as negatively correlated with paranoid ideation on BSI (r = −.23, p < .05) |
| Mean age not reported | Used the Q‐Set | Interviewer rating of symptoms (including suspiciousness) | Deactivating (avoidant) versus hyperactivating (anxious) | Interviewers conversely rated individuals with deactivating symptoms as more suspicious (r = .55) and more symptomatic overall | ||
| Community sample | No confounders controlled for | |||||
| Berry et al. (2008) UK | Longitudinal – cohort prospective | Schizophrenia (77), schizoaffective disorder (15), psychosis not otherwise specified (NOS) (4). (n = 96). 66 male | PAM | PANSS | Avoidance | Attachment avoidance was positively correlated with paranoia subscale score (r = .39, p < .001). No relationship found between attachment anxiety and paranoia (r = .19, p = .69) |
| 54 participated in study follow‐up. Mean age = 44 | PAM – informant version | Anxiety | Regression analysis found that attachment avoidance was a significant predictor of paranoia (β = .20, p = .44) independent of illness severity (controlled for by PANSS total score) | |||
| Inpatient and community sample | Attachment ratings were found to be moderately stable over time, and informant versions of the PAM showed replication of findings with similar levels of significance. The only significant association between change in symptoms over 6 months was in relation to attachment anxiety and hallucinations | |||||
| MacBeth et al. (2011) UK Scotland | Cross‐sectional | First‐episode psychosis sample; schizophrenia (11), schizoaffective disorder (3), persistent delusional disorder (2), bipolar affective disorder (11), mania with psychotic symptoms (1), recurrent depressive disorder with psychotic symptoms (2). (n = 34). 20 male | AAI | PANSS | Secure | Approximately a third of the sample coded as securely attached |
| Mean age not reported | Dismissing | No significant relationships found between attachment classifications and PANSS paranoia items (nor other PANSS items) | ||||
| Community sample | Preoccupied | No confounders controlled for | ||||
| Korver‐Nieberg et al. (2013) UK | Cross‐ sectional (case–control) | Early psychosis (according to ICD‐10; distinct diagnoses not described). (n = 32). 19 male | PAM | PANSS | Avoidance | Attachment anxiety was positively associated with ideas of social reference on GPTS (r = .42, p < .05) even after controlling for the frequency of positive and negative symptoms on the CAPE. Attachment anxiety reported as initially positively correlated with persecution on GPTS; however, this was no longer significant when controlling for frequency of symptoms |
| Mean age 17.1. | GPTS | Anxiety | Attachment avoidance was initially positively correlated with ideas of social reference but this was no longer significant after controlling for frequency of symptoms on the CAPE. Attachment avoidance was reported as significantly correlated with persecution on GPTS and this remained significant when controlling for symptoms frequency (r = .45, p < .05) | |||
| Community sample | CAPE | |||||
| Ponizovsky et al. (2013) Israel | Cross‐sectional | Schizophrenia (n = 100). 70 male | RQ | PANSS | Secure | Sample split into four RQ attachment subgroups: over half of the sample was classed as secure (and only 10 with dismissing) |
| Mean age 40.3 | Dismissing | In regression analyses, emotional distress combined with RQ attachment showed both preoccupied (β = .417, p < .0001) and fearful‐avoidant attachment (β = .353, p < .0001) style to be significant predictors of PANSS suspiciousness/persecution (and also PANSS delusions), whereas dismissing‐avoidant was not | ||||
| Community sample | Preoccupied | No other confounders controlled for | ||||
| Fearful | ||||||
| Wickham et al. (2015) UK | Cross‐sectional (case–control) | Schizophrenia (122), schizoaffective disorder (17), substance‐induced psychosis (6), PNOS (15), acute and transient psychotic disorder (12), delusional disorder (4). (n = 176). 123 male | RQ | Persecution and Deservedness Scale (PaDS) | Avoidance | Used RQ to yield scores on anxiety and avoidance attachment dimensions for main analysis |
| Mean age not reported. Range 17–77 years | PANSS | Anxiety | Correlational analyses showed both insecure attachment styles correlated with paranoia (anxiety: PaDS r = .44, PANSS r = .34, avoidance: PaDS r = .21, PANSS r = .24, all p < .01) | |||
| Community and inpatient samples | Regression analysis showed attachment anxiety significantly predicted paranoia in clinical sample using the PaDS when controlling for hallucinations, and the effect for attachment avoidance was did not reach significance. When using the PANSS and controlling for hallucinations, both attachment dimensions predicted paranoia. Neither attachment style predicted hallucinations when controlling for paranoia (both on PaDS and PANSS) | |||||
| A mediation model using clinical participants was estimated twice using different measures of paranoia (PaDS and PANSS item 6). Partial medication was reported for the relationship between attachment anxiety and paranoia (on both PaDS and PANSS) with negative self‐esteem as a mediator (PaDS = β = .014, p < .001; PANSS = β = .09, p < .01). Full mediation occurred between attachment avoidance and paranoia via self‐esteem (PaDS = β = .11, p < .001; PANSS = β = .07, p < .01) | ||||||
| All analyses controlled for age, sex and comorbidity of hallucinations | ||||||
| Korver‐Nieberg et al. (2015)a | Cross‐sectional | Schizophrenia (426), schizoaffective disorder (38), non‐affective psychosis (26) (n = 500). 402 males | RQ | PANSS | Avoidance | Pooled sample of 500 and analysed specifically looking at attachment and paranoia (PANSS suspiciousness item 6) |
| Mean age = 37.5 | Anxiety | PANSS item 6 suspiciousness/persecution was rated higher in individuals with any attachment insecurity (fearful‐avoidant, preoccupied, dismissing‐avoidant) compared to securely attached individuals | ||||
| Community and inpatient samples | RQ attachment dimensions were grouped into attachment anxiety and attachment avoidance. PANSS item 6 suspiciousness/persecution was associated with attachment anxiety (r = .183, p < .001) and attachment avoidance (r = .173, p < .001) | |||||
| No confounders controlled within correlational analysis | ||||||
| Strand et al. (2015) Sweden | Cross‐sectional | Schizophrenia (16), schizoaffective disorder (6), other psychoses (20), bipolar disorder (5). (n = 47). 30 male | RQ | Revised Symptom Checklist (SCL‐90R) | Secure | No significant association between secure attachment or dismissing attachment and symptoms |
| Mean age = 43.02 | Dismissing | The only significant positive correlation was between preoccupied attachment and paranoia (p = .001, r = .463) | ||||
| Community sample | Preoccupied | No confounders controlled for | ||||
| Fearful | ||||||
| Sitko et al. (2016) UK | Longitudinal – experience sampling method (ESM) (case–control) | Schizophrenia (6), Schizoaffective disorder (2), paranoid schizophrenia (8), PNOS (4). (n = 19). 16 male | RQ and ESM measure adapted from Adult Attachment Style (AAS) questionnaire. ESM measure validated against the RQ using a binary approach (secure vs. insecure) | PANSS | Secure | Linear regression found that attachment insecurity predicted the occurrence of paranoia. This relationship remained significant even when controlling for concurrent auditory hallucinations (β = .139, p = .001) and self‐esteem (β = .140, p = .001) |
| Mean age = 47.14 | ESM measure derived from PaDS and used in previous ESM studies (Udachina, Varese, Oorschot, Myin‐Germeys, & Bentall, 2012; Varese, Udachina, Myin‐Germeys, Oorschot, & Bentall, 2011 | Insecure – state attachment insecurity defined as a mean score of six statements derived from AAS | Auditory hallucinations also predicted by preceding elevated levels of attachment insecurity; however, this effect was no longer significant after controlling for paranoia | |||
| Community sample | Attachment insecurity still predicted and preceded paranoid thinking when controlling for self‐esteem | |||||
| Fett et al. (2016) UK | Cross‐sectional (case–control) | ICD‐10 psychotic episode (n = 39). 23 male | PAM | GPTS | Avoidance | Regression analysis found that attachment anxiety was positively associated with GPTS social reference (β = .70, p < .001) and persecution paranoia (β = .49, p < .001) |
| Mean age 17.1 | PANSS | Anxiety | Attachment avoidance was positively associated with GPTS social reference (β = .52, p < .001) and persecution paranoia (β = .43, p < .001) | |||
| Community sample | No confounders controlled for | |||||
| Castilho et al. (2017) Portugal | Cross‐sectional | Schizophrenia (33), schizoaffective disorder (3), PNOS (4). (n = 37). 30 male | ECR‐RS | PC | Avoidance | Initial analyses showed attachment anxiety was predominant. Correlational analyses found a significant association between attachment anxiety (in relation to mother) and PC frequency (r = .33, p = .05) |
| Mean age = 37.14 | Anxiety | Further analyses included experiential avoidance as a mediator between the relationship of attachment anxiety (in relation to mother) and frequency of paranoid ideation (PC). Experiential avoidance was reported to mediate this relationship. | ||||
| Inpatient sample | No confounders controlled for | |||||
| Pearce et al. (2017) | Cross‐sectional | Schizophrenia (35), schizoaffective disorder (19), delusional disorder (1), brief psychotic disorder (7), PNOS (13), other (20), no diagnosis (4), bipolar affective disorder (13) | RQ | CAPE | Secure | Of those that completed the RQ measure, the majority reported fearful attachment styles (n = 55) |
| (n = 131). Male 30 | Dismissing | Correlational analyses showed preoccupied and dismissive attachment were not associated with paranoia (nor voices). Fearful attachment was positively associated with paranoia (r = .54, p < .001) (and also associated with voices). Paranoia and voices reported as highly correlated | ||||
| Mean age = 40.26 | Preoccupied | Correlation comparison tests revealed that the correlation between fearful attachment and paranoia was larger than the correlation between fearful attachment and voices | ||||
| Fearful | Fearful attachment was found to mediate the relationship between childhood trauma and paranoia, when controlling for voices (β = .05, p < .05) | |||||
| Childhood trauma alone did not appear to predict paranoia independent of the mediators | ||||||
The Revised Symptom Checklist SCL‐90R – (Derogatis, 1997).
AAI = Adult Attachment Interview (George et al., 1996); AAS = Adult Attachment Style Questionnaire (Collins & Read, 1990); BSI = Brief Symptom Index (Derogatis & Spencer, 1982); CAPE = Community Assessment of Psychic Experiences (Stefanis et al., 2002); ECR‐RS = Experiences in Close Relationships – Relationship Structure (Fraley et al., 2011); GPTS = Green Paranoid Thoughts Scale (Green et al., 2008); PaDS = Persecution and Deservedness Scales (Melo et al., 2009); PAM = Psychosis Attachment Measure (Berry, Wearden, Barrowclough, & Liversidge, 2006); PANSS = Positive and Negative Syndrome Scale (Kay et al., 1987); PC = Paranoia Checklist (Freeman et al., 2005); RQ = Relationship Questionnaire (Bartholomew & Horowitz, 1991).