I just attended an interesting seminar on trauma and psychosis and CBT.
Psychosis is almost exclusively explained as a biological vulnerability. Trauma is often assumed to be linked to depression and anxiety but causality is not openly as linked to psychosis.
One researcher and psychiatrist Dr. Bill MacEwan, found that among those in the Downtown Eastside of Vancouver in a population that is highly addicted to substances there is a higher comorbidity of psychosis and childhood trauma than anxiety and childhood trauma. One explanation is that drug use mediates/masks the anxiety symptoms that trauma can produce and that increased drug use can trigger or exacerbate psychotic symptoms.
Notably Tony Morrison of the UK reported a study that found that in one study institutional care was especially significantly associated with paranoia and rape was associated with audio-visual hallucinations. Physical abuse alone was significantly linked to both paranoia and audio-visual hallucinations. Numerous other studies found the same link between psychosis and traumatic events, especially those in early childhood. Also: people can experience psychosis itself as traumatic and may go on to develop PTSD after having PTSD from the psychosis or institutional care.
This is particularly significant because it means a couple of things.
1) Preventing abuse of children could diminish those who experience psychosis
2) Understanding this link can help someone gain insight into their illness and through addressing trauma.
3) Our care should acknowledge this and seek to diminish further trauma and increased sense of safety.
For me going starting into a field working with people with psychosis and also with a huge passion for helping people with trauma this brought a new meaning to my work with those with psychotic illnesses and more perspective and ideas on how to understand those of my neighbors in the DTES with psychosis.