Katrina Witt

Dr. Katrina Witt


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 February 2013 in PLOS ONE
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KWKatrina Witt
Katrina Witt
RDRichard van Dorn
Richard van Dorn
SFSeena B. Fazel
Seena B. Fazel
Previous reviews on risk and protective factors for violence in psychosis have produced contrasting findings. There is therefore a need to clarify the direction and strength of association of risk and protective factors for violent outcomes in individuals with psychosis. We conducted a systematic review and meta-analysis using 6 electronic databases (CINAHL, EBSCO, EMBASE, Global Health, PsycINFO, PUBMED) and Google Scholar. Studies were identified that reported factors associated with violence in adults diagnosed, using DSM or ICD criteria, with schizophrenia and other psychoses. We considered non-English language studies and dissertations. Risk and protective factors were meta-analysed if reported in three or more primary studies. Meta-regression examined sources of heterogeneity. A novel meta-epidemiological approach was used to group similar risk factors into one of 10 domains. Sub-group analyses were then used to investigate whether risk domains differed for studies reporting severe violence (rather than aggression or hostility) and studies based in inpatient (rather than outpatient) settings. There were 110 eligible studies reporting on 45,533 individuals, 8,439 (18.5%) of whom were violent. A total of 39,995 (87.8%) were diagnosed with schizophrenia, 209 (0.4%) were diagnosed with bipolar disorder, and 5,329 (11.8%) were diagnosed with other psychoses. Dynamic (or modifiable) risk factors included hostile behaviour, recent drug misuse, non-adherence with psychological therapies (p values<0.001), higher poor impulse control scores, recent substance misuse, recent alcohol misuse (p values<0.01), and non-adherence with medication (p value <0.05). We also examined a number of static factors, the strongest of which were criminal history factors. When restricting outcomes to severe violence, these associations did not change materially. In studies investigating inpatient violence, associations differed in strength but not direction. Certain dynamic risk factors are strongly associated with increased violence risk in individuals with psychosis and their role in risk assessment and management warrants further examination.

1 October 2018 in eClinicalMedicine
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Jo RobinsonJo Robinson
Jo Robinson
EBEleanor Bailey
Eleanor Bailey
KWKatrina Witt
Katrina Witt
NSNina Stefanac
Nina Stefanac
AMAllison Milner
Allison Milner
SHSarah Hetrick
Sarah Hetrick
Young people require specific attention when it comes to suicide prevention, however efforts need to be based on robust evidence. We conducted a systematic review and meta-analysis of all studies examining the impact of interventions that were specifically designed to reduce suicide-related behavior in young people. Ninety-nine studies were identified, of which 52 were conducted in clinical settings, 31 in educational or workplace settings, and 15 in community settings. Around half were randomized controlled trials. Large scale interventions delivered in both clinical and educational settings appear to reduce self-harm and suicidal ideation post-intervention, and to a lesser extent at follow-up. In community settings, multi-faceted, place-based approaches seem to have an impact. Study quality was limited. Overall whilst the number and range of studies is encouraging, gaps exist. Few studies were conducted in low-middle income countries or with demographic populations known to be at increased risk. Similarly, there was a lack of studies conducted in primary care, universities and workplaces. However, we identified that specific youth suicide-prevention interventions can reduce self-harm and suicidal ideation; these types of intervention need testing in high-quality studies.

9 August 2016 in Cochrane Database of Systematic Reviews
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SHSarah Hetrick
Sarah Hetrick
GCGeorgina R Cox
Georgina R Cox
KWKatrina Witt
Katrina Witt
JBJulliet J Bir
Julliet J Bir
SMSally N Merry
Sally N Merry

29 August 2017 in Occupational and Environmental Medicine
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AMAllison Milner
Allison Milner
KWKatrina Witt
Katrina Witt
Anthony D. LaMontagneAnthony D. LaMontagne
Anthony D. LaMontagne
INIsabelle Niedhammer
Isabelle Niedhammer
Objectives Job stressors are known determinants of common mental disorders. Over the past 10 years, there has been evidence that job stressors may also be risk factors for suicidality. The current paper sought to examine this topic through the first comprehensive systematic review and meta-analysis of the literature to date. Methods We used a three-tier search strategy of seven electronic databases. Studies were included if they reported on a job stressor or job-related stress as an exposure and suicide ideation, self-harm, suicide attempt or suicide as an outcome. Two researchers independently screened articles. All extracted effect estimates were converted to log-transformed ORs. Results There were 22 studies that were included in meta-analysis. Overall, exposure to job stressors was associated with elevated risk of suicide ideation and behaviours. The OR for suicide ideation (14 studies) ranged from 1.45 (95% CI 1.01 to 2.08) for poor supervisor and colleague support to 1.91 (95% CI 1.22 to 2.99) for job insecurity. For suicide (six studies), exposure to lower supervisor and collegial support produced an OR of 1.16 (95% CI 0.98 to 1.38), while low job control resulted in an OR of 1.23 (95% CI 1.00 to 1.50). There were only two studies that examined suicide attempt, both of which suggested an adverse effect of exposure to job stressors. Conclusions This study provides some evidence that job stressors may be related to suicidal outcomes. However, as most studies in the area were cross-sectional and observational in design, there is a need for longitudinal research to assess the robustness of observed associations.

1 August 2016 in The Lancet Psychiatry
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KHKeith Hawton
Keith Hawton
KWKatrina Witt
Katrina Witt
TSTatiana L Taylor Salisbury
Tatiana L Taylor Salisbury
Ella ArensmanElla Arensman
Ella Arensman
DGDavid Gunnell
David Gunnell
KHKees van Heeringen
Kees van Heeringen
Self-harm (intentional acts of non-fatal self-poisoning or self-injury) is common, particularly in young adults aged 15-35 years, often repeated, and strongly associated with suicide. Effective aftercare of individuals who self-harm is therefore important. We have undertaken a Cochrane systematic review and meta-analysis of the effectiveness of psychosocial interventions for self-harm in adults. We searched five electronic databases (CCDANCTR-Studies and References, CENTRAL, MEDLINE, Embase, and PsycINFO) between Jan 1, 1998, and April 29, 2015, for randomised controlled trials of psychosocial interventions for adults after a recent (within 6 months) episode of self-harm. Most interventions were assessed in single trials. We report results for interventions for which at least three randomised controlled trials comparing interventions with treatment as usual have been published and hence might contribute to clinical guidance. The primary outcome was repetition of self-harm at the conclusion of treatment and at 6, 12, and 24 months' follow-up analysed, when available, with the intention-to-treat method; if this was not possible, we analysed with all available case data. We identified 29 non-overlapping randomised controlled trials with three independent trials of the same intervention. Cognitive-behavioural-based psychotherapy (CBT; comprising cognitive-behavioural and problem-solving therapy) was associated with fewer participants repeating self-harm at 6 months' (odds ratio 0·54, 95% CI 0·34-0·85; 12 trials; n=1317) and at 12 months' follow-up (0·80, 0·65-0·98; ten trials; n=2232). There were also significant improvements in the secondary outcomes of depression, hopelessness, suicidal ideation, and problem solving. Patients receiving dialectical behaviour therapy (in three trials) were not less likely to repeat self-harm compared with those provided with treatment as usual at 6 months (odds ratio [OR] 0·59, 95% CI 0·16-2·15; n=267, three trials) or at 12 months (0·36, 0·05-2·47; n=172, two trials). However, the secondary endpoint of frequency of self-harm was associated with a significant reduction with use of dialectical behaviour therapy (mean difference -18·82, 95% CI -36·68 to -0·95). Four trials each of case management (OR 0·78, 95% CI 0·47-1·30; n=1608) and sending regular postcards (OR 0·87, 95% CI 0·62-1·23; n=3277) did not reduce repetition of self-harm. CBT seems to be effective in patients after self-harm. Dialectical behaviour therapy did not reduce the proportion of patients repeating self-harm but did reduce the frequency of self-harm. However, aside from CBT, there were few trials of other promising interventions, precluding firm conclusions as to their effectiveness. National Institute for Health Research.

15 November 2019 in Australian & New Zealand Journal of Psychiatry
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KWKatrina Witt
Katrina Witt
JPJennifer Potts
Jennifer Potts
AHAnna Hubers
Anna Hubers
MGMichael F Grunebaum
Michael F Grunebaum
JMJames W Murrough
James W Murrough
KHKeith Hawton
Keith Hawton
Objective: Ketamine may reduce suicidal ideation in treatment-resistant depression. But it is not known how quickly this occurs and how long it persists. We undertook a systematic review and meta-analysis to determine the short- and long-term effectiveness of ketamine for suicidality. Method: CENTRAL, EMBASE, Medline, and PsycINFO were searched until 12 December 2018. Randomised controlled trials of ketamine or esketamine reporting data on suicidal ideation, self-harm, attempted or completed suicide in adults diagnosed with any psychiatric disorder were included. Two reviewers independently extracted data, and certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. Standardised mean difference was used for continuous outcomes. Results: Twenty-five reports from 15 independent trials, with a total of 572 participants diagnosed with predominately affective disorders, were included. The evidence was rated moderate to low. In most trials, ketamine was administered at 0.5 mg/kg via a single intravenous infusion over a 30- to 45-minute period. Only a single trial of intranasal esketamine was identified. At 4 hours post-infusion, treatment with ketamine was associated with a significant reduction in suicidal ideation scores (standardised mean difference = −0.51, 95% confidence interval = [−1.00, −0.03]), which persisted until 72 hours post-infusion (time points between 12 and 24 hours: standardised mean difference = −0.63, 95% confidence interval = [−0.99, −0.26]; between 24 and 72 hours: standardised mean difference = −0.57, 95% confidence interval = [−0.99, −0.14]), but not thereafter. However, there was marked heterogeneity of results. In a single trial of esketamine, marginal effects on suicidal ideation were observed. In terms of actual suicidal behaviour, there were virtually no data on effects of ketamine or esketamine. Conclusion: A single infusion of ketamine may have a short-term (up to 72 hours) beneficial impact on suicidal thoughts. While confirmation of these results in further trials is needed, they suggest possible use of ketamine to treat acute suicidality. Means of sustaining any anti-suicidal effect need to be found.