Are humour-based interventions effective in treating people with schizophrenia?
Schizophrenia is a serious mental illness. It is a disorder of thought, namely firm fixed false beliefs despite there being evidence to the contrary, loss of reality ties, and altered perception. These symptoms are further classified as (i) positive symptoms, such as speech without order, illusions or mistaken and persistent ideas; and (ii) negative symptoms, a lack of emotion or restricted quantity of speech; and decline in cognitive function, including attention, memory, and behavior control. The standard treatment for schizophrenia is antipsychotic medications. Treatment with humour-based interventions, such as watching humorous movies, funny videos, or comedies, has been proposed as an add-on treatment that promotes health and wellness by stimulating a playful discovery, expression, or appreciation of the irrationality or inconsistency of life's situations.
Searching for evidence
We ran an electronic search in February 2021 for trials that randomised people with schizophrenia to receive humour-based interventions in addition to usual care, or to receive usual care only, another psychological intervention or a control condition. We found eight records and checked them for suitability to include in our review.
Three trials met the review requirements and two low-quality trials (total number of participants = 96) provided useable data. Compared with active control, humour-based interventions may not improve positive symptoms and anxiety, but may improve depressive symptoms. However, when compared with standard care, humour-based intervention may not improve the depressive symptoms. Current evidence is very limited and is of low to very low quality. We are uncertain as to whether humour-based interventions may lead to clinically-important improvement in mental state or quality of life in people with schizophrenia.
There is insufficient research evidence to support the use of humour-based interventions in people with schizophrenia.
We are currently uncertain whether the evidence supports the use of humour-based interventions in people with schizophrenia. Future research with rigorous and transparent methodology investigating clinically important outcomes is warranted.
Humour-based interventions are defined as any intervention that promotes health and wellness by stimulating a playful discovery, expression, or appreciation of the absurdity or incongruity of life's situations. Humour-based interventions can be implemented in different settings, including hospitals, nursing homes and day care centres. They have been posed as an adjunct to usual care for people with schizophrenia, but a summary of the evidence is lacking.
To examine the effects of humour-based interventions as an add-on intervention to standard care for people with schizophrenia.
On 31 July 2019 and 10 February 2021 we searched the Cochrane Schizophrenia Group's study-based register of trials, which is based on CENTRAL, CINAHL, ClinicalTrials.Gov, Embase, ISRCTN, MEDLINE, PsycINFO, PubMed, and WHO ICTRP.
We included all randomised controlled trials comparing humour-based interventions with active controls, other psychological interventions, or standard care for people with schizophrenia. We excluded studies fulfilling our prespecified selection criteria but without useable data from further quantitative synthesis.
Two review authors independently inspected citations, selected studies, extracted data and appraised study quality, following the guidance from the Cochrane Handbook for Systematic Reviews of Interventions. For binary outcomes we calculated risk ratios (RRs) and their 95% confidence intervals (CIs). For continuous outcomes we calculated the mean differences (MDs) and their 95% CIs. We assessed risks of bias for included studies and created summary of findings tables using the GRADE approach.
We included three studies in this review for qualitative synthesis, although one study did not report any relevant outcomes. We therefore include two studies (n = 96) in our quantitative synthesis. No data were available on the following prespecified primary outcomes: clinically-important change in general mental state, clinically-important change in negative symptoms, clinically-important change in overall quality of life, and adverse effects. As compared with active control, humour-based interventions may not improve the average endpoint score of a general mental state scale (Positive and Negative Syndrome Scale (PANSS) total score: MD −1.70, 95% CI −17.01 to 13.61; 1 study, 30 participants; very low certainty of evidence); positive symptoms (PANSS positive symptom score: MD 0.00, 95% CI −2.58 to 2.58; 1 study, 30 participants; low certainty of evidence), negative symptoms (PANSS negative symptom score: MD −0.70, 95% CI −4.22 to 2.82; 1 study, 30 participants; very low certainty of evidence) and anxiety (State-Trait Anxiety Inventory (STAI): MD −2.60, 95% CI −5.76 to 0.56; 1 study, 30 participants; low certainty of evidence). Due to the small sample size, we remain uncertain about the effect of humour-based interventions on leaving the study early as compared with active control (no event, 1 study, 30 participants; very low certainty of evidence). On the other hand, humour-based interventions may reduce depressive symptoms (Beck Depression Inventory (BDI): MD −6.20, 95% CI −12.08 to −0.32; 1 study, 30 participants; low certainty of evidence). Compared with standard care, humour-based interventions may not improve depressive symptoms (BDI second edition: MD 0.80, 95% CI −2.64 to 4.24; 1 study, 59 participants; low certainty of evidence). We are uncertain about the effect of humour-based interventions on leaving the study early for any reason compared with standard care (risk ratio 0.38, 95% CI 0.08 to 1.80; 1 study, 66 participants; very low certainty of evidence).