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what is the evidence for and against the roles of traumatic experiences in…

- - - - intrusive memories out of context
        
        sense of otherness
        
        this then links to dissociation and source monitoring
        
        Read et al. (2005) (112) sugest ambiguity between inner and outer experiences may be a way of avoiding reliving the trauma.
        
        missattribution (source error) from internal to external would lead to a reduction in distress
        
        hippocampal hyperactivation present supporting that AVHs are memory intrusions
        
        high degrees of stress can reduce the reactivity of the hippocampus, leading to a hyperarousal state. trauma causes stress, stress alters connections between hippocampus and parahippocampal gyri which integrate and transfer information into the hippocampus. so information from hippocampus may be incorrectly activated and generate a hallucinatory response
        
        activity in the left parahippocampal gyrus and the hippocampus has been related to AVHs (Jardri et al 2011)
        
        increased frontotemporal activity involved in speech perception and medial temporal lobe which is involved in verbal memory
        
        "weak contextual integration during he encoding of highly stressful traumatic memories may lead to involuntary triggering in those with biological vulnerability" Bailey et al 2018
      - auditory hallucinations are auditory representations derived from unintentional activation of memories and other irrelevant current mental associations. a combination of deficits in intentional inhibition and contextual memory is critical for AHs
        
        failure in intentional inhibition produces uncontrollable events which aren't recognised because the contextual cues that would usually facilitate recognition have been lost.
        
        goes against traumatic experiences, because the model says any memory can be unintentionally recalled, not just traumatic ones, and the problem is with the contextual cues and inhibition.
        
        can then make the point here that traumatic memories are intrusive.
        
        intrusive memories don't account for the more complex auditory experiences
        
        for example, neutral or benevolent voices. although they are less common in schizophrenia they still occur
        
        2 more items...
        
        the role of memory in AVHs might not necessarily be traumatic ones
        
        Hardy et al (2005) found 12.5% of hallucinations were a direct replication of trauma and 45% had an emotional link
        
        3 more items...
        
        Waters et al. (2006) is this view
  - - - first, source monitoring deficits precede trauma. those that experience trauma later end up with intrusive involuntary cognition, and those with source monitoring deficits misattribute these as hallucinations.
        
        it may take time, as the person dealing with the trauma later becomes retraumatised (Honig et al. 1998)
      - second, trauma impedes source monitoring ability. hallucinations are associated with dissociation, which involves a failure of integration of information processing, so some normally conscious mental activities are performed without awareness, and source monitoring may be adversely affected as a consequence.
      - third, incorporates the assumption that psychotic experiences occur on a continuum in the general population. the experience of thoughts misattributed to an external source as a result of biased source monitoring is a common phenomenon, but trauma differentiates between patients and non-patients.
        
        if this was the case, trauma should be much less closely associated with voices in non patient groups
    - - Bentall et al (2013) found that for those with FEP, those with CSA had more severe hallucinations than those without CSA. they also did an emotional troop test and found that post traumatic intrusions at clinical levels and showed selective attention to CSA related words. this does suggest that trauma affects the severity of hallucinations, but I have to be careful when specifying this to DEVELOPING AVH
        
        However, Bentall et al. (2011) gave FEP and matched non clinical controls a source monitoring task and found no externalising bias for trauma words in those with childhood trauma. this suggests external source monitoring bias may not be central to hallucinations early in psychosis. it does not support the idea that intrusive memories of trauma are externally misattributed
        
        therefore, trauma may not play a role in the development of AVH, but potentially the severity of later AVH.
        
        can then link this to another theory that isn't related to externalising biases.
        
        Dissociation maybe?
        
        Daalman et al. (2012) found both psychotic and non psychotic patients with AVH experienced more sexual and emotional abuse when compared with healthy controls. suggests that these abuse types make a person more vulnerable to experience AVHs.
        
        suggests maybe trauma isn't the difference between clinical and non-clinical populations as the AVH non psychotic group had trauma but no diagnosis. maybe trauma affects AVH regardless of schizophrenia.
        
        the link here is that one says trauma might not play a role in developing schizophrenia, just later severity, the other says trauma plays a role in AVH regardless of schizophrenia diagnosis.
        
        found childhood trauma was significantly correlated with hallucination severity, which included clinical samples. (Bailey et al. 2018)
    - - 3 vulnerabilities
        
        attempts to survive trauma become habitual ways of regulating emotions, manifesting in cognitive and behavioural responses
        
        event memories are impacted by emotion experienced during trauma
        
        semantic memory- appraisals of the self and others, are shaped by event memories
      - two types of intrusion
        
        anomalous experience rising from emotion regulation or generation of novel images derived from trauma memory
        
        hypervigilance to danger following childhood trauma could result in reduced threshold for threat detection
        
        environmental noise is perceived as threat, leading to intrusions of anomolous experience
        
        dissociative detachment- dissociation in an attempt to manage threat could give rise to intrusive experiences because it has a detrimental impact on sensory perceptual processes, so it allows consciousness to be intruded upon
        
        autobiographical memory- the working self draws on personal memory representations to generate novel imagery
        
        these intrusions that are driven by emotion regulation and autobiographical memory might explain experiences that appear unrelated to trauma history.
        
        trauma memory intrusions reflecting the retrieval of representations
        
        there is a continuum of memory intrusions, and fragmented memory, where the memory is present without the contextual cues to put these in place will lead to a misattribution of the source. those memories that are fragmented are unlikely to be perceived as arising from memory events.
      - this can be an integrative account at the end I think
    - - Humpston et al (2017) found that the positive dimension of schizotypy was positively correlated with internal and reality monitoring errors in an action based task.
      - to disagree with this again: Waters et al (2012) found reduced self recognition performance in schizophrenia patients, which was more pronounced for patients with AH
  - - - VH experiences can be most appropriately understood as dissociated or disowned components of the self that result from trauma, loss or interpersonal stressors
        
        argued that dissociative responses to serious adverse experiences could fragment ordinary memory processing
        
        verbatim memory for what the voices said is poor, so they aren't remembered experiences (Sachs, 1967)
        
        Read et al (2003) also in 112 found child abuse predicted AH in a mixed psychiatric sample
        
        Trauma exposure in childhood results in heightened sensitivity to stress and perceived threat- Bremner 2002, Nemeroff 2004, Read et al 2001
        
        if there is more perceived threat in the environment this can exacerbate symptoms
        
        the traumatic content of the AVH can be contributing and reinforcing the symptoms, leading to a feedback loop of trauma by reinforcing it
    - - dissociation positively mediated the effect of childhood trauma on hallucination proneness (not AV specific). this was particularly robust for sexual abuse
      - found source monitoring was impaired in both currently hallucinating and remitted hallucinating patients.
        
        No association between source monitoring performance and childhood trauma was found
        
        source monitoring may play a role in AVH without the role of trauma
    - - Perona-Garcalen et al (2012)
        
        and Varese et al 2011 found reports of dissociation reliably preceded the onset of AVH. these obviously require further research but it is an interesting point.
- - - - reliability of self report measures
        
        questions of the reliability of report is not based in evidence
        
        Darves-Bornoz et al (1995) found "the problem of incorrect allegations of sexual assaults was no different for schizophrenics than the general population"
        
        Goodman, Thompson and Weinfurt (1999) found those with a serious mental illness showed good consistency for reports of abuse occurance
        
        traumatic memories are often formed into information that is not identical to the experienced event (Conway & Pleydell-Pearce, 2000)
        
        this is likely to exacerbate the potential for confusion when experiencing hallucinations and attempts to locate the origin of these phenomena
- - - - hallucinations were significantly more common for the abued group than the non-abused group. adult sexual assault was related to hallucinations in general, and child abuse was a significant predictor of auditory hallucination, even in the absence of adult abuse
    - - multiple types of trauma were associated with increased in the likelihood of auditory hallucinations
    - - dose response relationship was found between number of childhood traumas and risk of AVH.
    - - also found a dose response relationship
      - this is contrary to Shelvin et al (2006), who found physical assault wasnt associated with AH
    - - Although McCarthy-Jones (2011) found that those with CSA experiences were more likely to report AVHs than those without, and vice versa, they concluded a causal relationship cannot be established due to the failure to control for potential confounding variables.
- - - - Spauwen et al (2006) speculated that extended exposure to trauma may increase risk for dopamine hyperactivity in the mesocorticolimbic system and prolonged exposure to aversive environments can lead to sensitisation of the system.
      - Da Bellis et al. (1994) also found elevated dopamine metabolism in girls who have been sexually abused.
        
        this research is outdated and more needs to be done to establish whether this is accurate to schizophrenia.
      - Read et al (2005)- suggested that early prolonged and severe trauma can permanently affect the HPA axis. dopamine is involved in post stress maintenance in the HPA axis (Belda and Armario, 2009)
        
        Heim et al (2000) found HPA dysregulation in women who were abused in childhood
        
        more research needed to see if this applies to schizophrenia