Schizophrenia and Cannabis

Sheila Caffell's Mental Health and the Use of Illegal Drugs

Not enough credence is given to the link between Sheila Caffell’s mental illness and her use of Cannabis and other illegal drugs. For instance 30-40% of diagnosed schizophrenics attempt suicide and the use of cannabis can prolong and exacerbate the symptoms of mental illness. Medical assessments showed Sheila Caffell displayed “textbook” delusions associated with schizophrenia, yet her state of mind and its role in the murders was constantly overlooked. Advances over the years have shown the link not only exists but also that it is wholly destructive - this comprehensive review reveals the devastating detail.

The Case of Sheila Caffell: The Effects of Illegal Drugs on People with Schizophrenia. Last updated 20.01.13

Original material by T. Whitefoot; additions by L. Lake; J. Martin-Adams; P. A. Miller.

In the early hours of 7th August 1985, five people were shot to death at White House Farm: Sheila Caffell, her twin six year old sons, and her adoptive parents, June and Nevill Bamber. Initially, Essex police believed that Sheila carried out the shootings and then committed suicide[1]. However, in the weeks that followed, that view changed and Jeremy Bamber, Sheila’s brother (also adopted, but no blood relation), was arrested and later convicted for the murders of Sheila, Nevill, June and the twins. He has been in prison since then for a crime which he did not commit. The purpose of this article is to explain the link between schizophrenia and cannabis and to show how Sheila Caffell’s collapsing mental health caused her to suffer a psychotic episode which resulted in the murder of her family.

Schizophrenia is a mental disorder, characterised by a disintegration of the thought process, and a breakdown of emotional responses[2]. Most commonly, the disorder manifests itself in the form of paranoid or bizarre delusions, auditory hallucinations and/or disorganised, incoherent speech and thinking. It is believed that genetics can sometimes play a role in predisposing a person to develop the illness, but other causal factors, such as a history of mental illness and/or abuse of drugs and alcohol, have also been discussed[3]. There is no laboratory test to determine schizophrenia[4]; a diagnosis is made based on the patient’s self- reported symptoms, and a clinical assessment. It has been recorded that approximately 30-40% of diagnosed schizophrenics attempt suicide at some point during their lifetime and one in ten of these will succeed in taking their own life[5]. It has also been established that people between the ages of 16-30 are more vulnerable to developing psychosis[6]. It is also within this age range that people are more likely to use cannabis[7].

In recent years, a great deal of research has been conducted[8] in order to establish a link between schizophrenia and the effects of cannabis and other recreational drugs. Over thirty clinical studies have taken place over the past twenty years, mostly in the UK, Sweden and Australia. It is now widely believed that using cannabis can prolong the symptoms of mental illness and impede a patient’s chances of recovering from a psychotic episode[9]. If a patient has already developed schizophrenic symptoms, the continuing use of cannabis and other substances, such as alcohol or amphetamines, is believed to have a detrimental effect on their illness[10]. Set out below are two examples of the research that has been conducted so far. 1. The authors of a study published in the American Journal of Psychiatry in May 2010 conducted a study over a period of ten years. Patients were examined during the initial first period of psychiatric hospitalisation and then six months later, and then two years, four years and, finally, ten years later. At each assessment patients were rated on their psychiatric symptoms and their use of cannabis. The study concluded that cannabis use is associated with an adverse course of psychotic symptoms found in schizophrenia sufferers[11].

2. In a study conducted at the Zucker Hillside Hospital in New York, researchers used a special kind of Magnetic Resonance Imaging (MRI) known as Diffusion Tensor Imaging (DTI) to measure the motion of water molecules which can indicate microscopic abnormalities in the brain. The test group included adolescents with and without schizophrenia, and adolescent users and non-users of cannabis. The MRI imaging revealed that heavy users of cannabis were found to have the type of abnormalities found in certain areas of the brain which are also found in the brains of subjects with schizophrenia[12]. These abnormalities were most pronounced in subjects with schizophrenia who were also regular users of cannabis[13]. The abnormalities occur in a pathway of the brain which is related to auditory and language functions which undergoes development during adolescence. The research suggested that if an adolescent is genetically predisposed to develop schizophrenia, the use of cannabis can cause the same type of damage to the brain’s pathway that is caused by schizophrenia. Put more simply, regular and prolonged use of cannabis could kick-start the development of schizophrenia where it might otherwise not have developed at all, or cause an earlier onset of the illness, and/or cause the condition to worsen [14].

Sheila Caffell’s mental health issues probably surfaced initially in 1981 when social workers reported injuries to her twin sons, and she was described as forgetful and disorganized.[15] She was referred for psychiatric treatment to Dr Ferguson in 1983, but she had been suffering from depression for eighteen months or so previously[16]. She was diagnosed as suffering from paranoid schizophrenia[17]. In addition to cannabis, she was also reported to have used other recreational drugs on occasion, such as cocaine and amphetamine[18]. Having divorced her husband Colin Caffell twelve months earlier, she was believed to have acquired considerable debts in support of her drug addiction[19].

Sheila was admitted as an in-patient to St. Andrews Hospital, Northampton in August 1983 following an acute breakdown[20]. During the course of her treatment, she was observed to display a number of classic ‘textbook’ delusions associated with paranoid schizophrenia. Dr Ferguson detailed that she had been in a state of acute psychosis and had been for about two weeks[21]. These included religious delusions about being given the responsibility of ridding the world of evil, delusions about her children being ‘the devil’s children’, and references to incestuous sex with her son's whom she described as 'the devil's children.'[22].

When she was discharged one month later, having made only a partial recovery[23], Sheila had been prescribed Stelazine[24], an anti-psychotic drug which is typically the first line of defence in the treatment of schizophrenia[25]. People with schizophrenia are usually found to have high levels of dopamine activity[26]. Stelazine works by blocking dopamine receptors in the brain, thus alleviating or minimising schizophrenic symptoms of delusions, hallucinations and disorganised thought or speech. Common side effects of Stelazine are nausea, headaches, dizziness, menstrual irregularities and agitation. Major side effects are lowered life span, dyskinesia and akathisia (see glossary below).

In March 1985, Sheila was again admitted to St Andrews Hospital following a severe psychotic episode [27]. She had suffered violent outbursts, one of which was witnessed by a friend who was left traumatised by the event[28]. During a stay of only three weeks, Sheila admitted to having used cocaine frequently[29]. It appears that Dr Ferguson did not raise the issues about Sheila harming her children because of client confidentiality. Despite the fact that Nevill was paying for the treatment, Sheila was the patient. It is also important to remember that Sheila was an 'informal' patient; that is, she was not subject to a 'section' under the Mental Health Act 1983. Therefore she was advised about her treatment but could not be legally required to comply. This undoubtedly had far reaching implications.[29a] At this time, Sheila was prescribed three kinds of medication: [30].

Anafranil - is a brand name of the chemical called Clomipramine. A tri-cyclic anti-depressant used a lot in the 1980swhen it was considered to be very successful in the treatment of depression. It typically takes 2 – 3 weeks to become effective. Caution is always required as suicide is always possible for a depressed or a disturbed patient. Side effects include confusion, agitation, insomnia and nightmares[31];

Haloperidol - is the chemical name which is typically branded as Serenace in the UK - a very strong anti-psychotic drug with sedative qualities. It is noted as being the most common neuroleptic associated with extra-pyramidal symptoms[32]. Clinical trials have shown that a medium to high dose of Haloperidol for a two-week period dramatically increased the dopamine activity up to 98%[33]. Long term effect is not known, but severe dyskinesia is indicated, and long-term, high-dose treatment may result in depression severe enough to result in suicide[34];

Procyclidine - often branded as Kemadrin is used to counteract the effects of anti-psychotic medications. Known side effects include agitation, confusion and insomnia[35].

Additionally, there is the issue of non-compliance. It is well known that patients who are required to self-medicate will often fail to take prescribed medication for two main reasons: one is that they do not believe they are ill and therefore believe the medication is unnecessary; the second is the result of the side-effects which many individuals find to be so extreme that they would prefer to tolerate their symptoms.[35a]

In July 1985, Sheila requested that her dose of Haloperidol be reduced. Her GP, Dr Angeloglou, contacted Dr Ferguson to discuss this for reasons unknown, but it is possible that Sheila had experienced some of the aforementioned side effects. The reduction of her dose from 200mg to 100 mg is the kind of sudden reduction which is potentially very dangerous, as it may have caused severe withdrawal symptoms, or even a return of the original condition. In addition to this, because she was due another injection, any side effects would have completely diminished[36].

At the family dinner which took place at White House Farm on the night of the murders, the subject of Sheila’s twin boys being put into foster care was raised[37]. Sheila’s psychiatrist stated that the effect of this news would have been ‘catastrophic’, and may well have been the trigger for a psychotic episode[38]. Her post-mortem results showed no trace of Anafranil, but cannabis and Haloperidol were found[39]. Failure to take some of her medication would have been exacerbated by the taking of cannabis and also the sudden reduction of her Haloperidol - could have caused her already fragile mental health to crumble completely. In 1985, the public and the police were perhaps reluctant to believe that a young mother could murder her own family with such brutality. In the twenty-first century, reports of women committing violent crime, including murdering one's own children before suicide, or attempted suicide - are well documented in the media. The outcome of Jeremy Bamber’s trial may well have been different had it taken place more recently, and if the jury had been made aware of research into the links between cannabis and schizophrenia. In fact, it is highly likely that Sheila Caffell’s life would have been saved, had the advances made in understanding schizophrenia and its treatment been available in 1985.

It is also a debatable point as to whether her treatment would have been very different if Care in the Community had not been in the process of being phased in during the 1980s. Prior to this development, it had been standard for all patients with a diagnosis of schizophrenia to be admitted to hospital for long-term care which usually translated into life-long inpatient care.

Glossary of Medical Terms

Akathisia – characterised by sensation of ‘inner restlessness’ or inability to remain motionless or to sit still[40].

Dystonia – characterised by contraction of muscle groups that cause repetitive or twisting movements or abnormal postures[41].

Tardive Dyskinesia – characterised by repetitive, involuntary movements of the body, commonly associated with anti-psychotic drugs such as Haloperidol[42].

Psuedo-Parkinsons – characterised by the symptoms of Parkinsons disease[43].


[1] D.Sup Ainsley (6/9/1985) Interview with Metropolitan Police Stokenchurch [on-line] Available at: [Accessed 11 January 2013].

The Mirror (8/8/1985) Mother Shoots Twin Sons and Parents [on-line] Available at: [Accessed 11 January2013].

Dr Vanezis, Pathology report DI Dickinson Enquiry, November, 1986, retrospectively states that he was satisfied that it was a suicide and four murders.

[2] See me, Schizophrenia (2008) What is it? Signs and symptoms [on-line] Available at: [Accessed 7 January 2013]

NHS Choices (2012) Schizophrenia Diagnosis. ‘Diagnosing Schizophrenia’ [on-line] Available at: [Accessed 7 January 2013]

[3] Schizophrenia Research (1999) ‘Dual Diagnosis of Substance Abuse in schizophrenia: prevalence and impact on outcomes’ [on-line] Available at: [Accessed 6 January 2013] (1996-2004) ‘Hereditary and the Genetics of Schizophrenia. Family statistics’ [on-line] Available at: [Accessed 13 January 2013]

[4] (2010) ‘How is Schizophrenia Diagnosed? Symptom of Schizophrenia and Schizophrenia Diagnosis’ [on-line] Available at: [Accessed 9 January 2013]

[5] Spokeane Mental Health (2010) ‘Schizophrenia. Facts about Schizophrenia. Suicide Attempts.’ 'About 1 in 4 schizophrenics attempts suicide; 1 in 10 succeed' [on-line] Available at: [Accessed 9 January 2013]

Annals of General Psychiatry (2007) ‘Suicide risk in schizophrenia: learning from the past to change the future. Background’ [on-line] Available at: [Accessed 10 January 2013]

[6] Berkshire Healthcare NHS Foundation Trust (2013) ‘Psychosis onset usually occurring in young people’ (80%, aged 16-30) [on-line] Available at: [Accessed 10 January 2013]

Here to Help, (2006) What’s going on with me? Signs & Symptons of Psychosis. [First experiences with psychosis are more common in people aged 16-30.] Available at [Accessed 18 January 2013]

[7] The Guardian ( 2012) DATA BLOG [on-line] Available at: [Accessed 10 January 2013]

[8] (1996-2010) ‘Street Drugs and Schizophrenia’ [on-line] Available at: [Accessed 9 January 2013]

[9] (2009) ‘US National Library of Medicine, National Institutes of Health. Cannabis and psychosis: search of a causal link through a critical and systematic review.’ [on-line] Available at: [Accessed 10 January 2013]

Psych Central (2012) ‘Schizophrenia and Psychosis. Delusions & Hallucinations are Common in Schizophrenia’ Para6 [on-line] Available at: [Accessed 10 January 2013]

[10] Everyday Health (2009) ‘Can Drug Use Cause Schizophrenia?’ Some evidence points to a link between illicit drug use especially marijuana and schizophrenia [on-line] Available at: [Accessed 10 January 2013]

Health (2002) ‘Disorders and conditions. Co-Occurring Alcohol Use Disorder and Schizophrenia.’ [on-line] Available at: [Accessed 10 January 2013]

[11] The American Journal of Psychiatry (2010) ‘Cannabis Use and the Course of Schizophrenia: 10-Year Follow-Up After First Hospitalization.’ [on-line] Available at: [Accessed 10 January 2013]

[12] Zucker Hillside Hospital

[13] Ibid

[14] The Lancet (2007) ‘Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review’ [on-line] Available at: [Accessed 11 January 2013]

[15] The Official Web Site of Jeremy Bamber, 2013., End notes 7-10, regarding the statements of social workers and Doctors who treated Sheila.

[16] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 9 January 2013]

'Mind' Understanding Depression [on-line] Available at: [Accessed 9 January 2013]

[17] Medical News Today, MNT. (2010) What Is Paranoid Schizophrenia? What Causes Paranoid Schizophrenia? [on-line] Available at: [Accessed 10 January 2013]

[18] 'FRANK' COCAINE, THE RISKS [on-line] Available at: [Accessed 10 January 2013]

Dr Ferguson, Handwritten Statement, 30th September 1986. Details her use of Cannabis, Cocaine and Amphetamine.

Colin Caffell, Statements handwritten, 11th September, 1985, he states that Dr Ferguson had contacted him by telephone concerned that Sheila had been taking cocaine through her involvement with Farhad Emami.

[19] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 9 January 2013]

[20] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 10 January 2013]

[21] Mayo Clinic (2010) Paranoid schizophrenia, signs and symptoms of paranoid schizophrenia [on-line] Available at: [Accessed 11 January 2013]

[22] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 9 January 2013]

Dr Ferguson, Statement, 8th August, 1985, details her behaviour, his diagnosis.

[24] eMedicineHealth, Medications and drugs, Stelazine (trifluoperazine) [on-line] Available at: [Accessed 11 January 2013]

[25] eMedtv (2008) Stelazine is a prescription medicine...treatment of schizophrenia...[on-line] Available at: [Accessed 11 January 2013]

[26] Oxford Journal (2009) Schizophrenia Bulletin Howes, Kapur The Dopamine Hypothesis of Schizophrenia: Version III—The Final Common Pathway [on-line] Available at: [Accessed 11 January 2013]

[27] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 11 January 2013]

[28] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 11 January 2013]

Dr Ferguson Statement Op cit, n 22

Farhad Emami (Freddie) (1985) statement: [on-line] Available at: [Accessed 11 January 2013]

Pathologist Views: Professor Peter Vanezis [on-line] Available at: [Accessed 11 January 2013]

[29] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 11 January 2013]

[29a] How and Why Sheila Did it

[30] 12.09.85 & 20.09.85 Dr Angeloglou Statement, 09.10.85 Dr Wilkinson, Statement, collective statements of Dr Ferguson regarding medication and its impact on Sheila and her erratic attendance to have medication and appointments.

Suzette Ford Interview (1986) [on-line] Available at: [Accessed 11 January 2013]

Helena Grimster (1986) statement [on-line] Available at: [Accessed 11 January 2013]

[31] Drug (2007) Anafranil (Clomipramine Hydrochloride) Warnings and Precautions. Clinical Worsening and Suicide Risk [on-line] Available at: [Accessed 12 January 2013]

[32] Psychiatric Nursing (2012) Neuroleptic-Induced Extrapyramidal Symptoms [on-line] Available at: [Accessed January 13 2013]

[33] Wikipedia (2013) Haloperidol, Adverse Effects 'increase dopamine activity, up to 98%' [on-line] Available at: [Accessed January 12 2013]

[34] Drugcite (2013) Haloperidol and Suicide Attempt...'Suicide attempt has been reported to the FDA a total of 229 times for Haloperidol' [on-line] Available at: [Accessed 12 January 2013]

[35] Medline Plus (2010) Procyclidine. What side effects can this medication cause? [on-line] Available at: [Accessed 12 January 2013]

[35a] Op Cit n 30, Sheila's reluctance to take medication and reliability to keep appointments.

Why don't patient's take their Medicine (2007) Available at [Accessed 20.01.13]

[36] EMC Medicine guides (2012) Haloperidol. Stopping your medicine. Withdrawal symptoms [on-line] Available at:,%20restlessness%20and%20agitation [Accessed 12 January 2013]

Medications, Op Cit, n29 Sheila’s medication

[37] Statement of Jeremy Bamber, Statement, 7th and 8th August 1985.

Colin Caffell, Over the Rainbow, details that Caffell had told Sheila he intended to go for custody of the children, he advised Sheila as he drove her and the children to white house farm shortly before their deaths.

[38] Jeremy Bamber (2010) Sheila Caffell's Mental Health [on-line] Available at: [Accessed 11 January 2013]

Health (2010) Expert Consensus Treatment Guidelines for Schizophrenia: A Guide for Patients and Families [on-line] Available at: [Accessed 12 January 2013]

BMC Psychiatry (2011) 1. Background. Self-esteem is associated with premorbid adjustment and positive psychotic symptoms in early psychosis [on-line] Available at: [Accessed 12 January 2013]

[39] 04.10.85 Alexander Allan, Toxicologist, Statement

[40] Clinical Trials.Gov. (2005) Akathesia, (Restless Leg Syndrome) in People With Schizophrenia and Mental Retardation [on-line] Available at: [Accessed 7 January 2013]

[41] Distonia Medical Research Foundation (2010) Drug induced [on-line] Available at: [Accessed 7 January 2013]

[42] Mind (2012) Understanding Tardive Diskinesia [on-line] Available at: [Accessed 8 January 2013]

[43] Parkinson's UK (2008) Parkinson's Disease Society. Drug-Induced Parkinsonism, Information Sheet [on-line] Available at: [Accessed 8 January 2013]