Meta-analysis shows cognitive therapy reduces negative symptoms in schizophrenia

A systematic review and meta-analysis of cognitive-behavioral therapy (CBT) has shown promising results in reducing negative symptoms of schizophrenia, according to recent research. Negative symptoms, which include blunted affect, alogia, avolition, asociality, and anhedonia, significantly affect patients’ quality of life and recovery. Current treatments for these symptoms have limited efficacy, prompting a need for effective alternatives.

CBT is a structured psychotherapy that focuses on modifying negative thought patterns and behaviors. It helps patients challenge irrational beliefs and encourages positive behavioral changes. This study aimed to evaluate the effectiveness of CBT on negative symptoms and overall functioning in individuals with schizophrenia through a meta-analysis of randomized controlled trials.

The analysis included data from 15 studies with a total of 1,311 participants, who were predominantly male. The Positive and Negative Syndrome Scale (PANSS) was the primary tool used to assess negative symptoms across all studies. The findings indicated that CBT led to a statistically significant reduction in negative symptoms compared to treatment as usual (TAU), with a mean difference (MD) of -1.65 (95% CI = -2.10 to -1.21, p < 0.001), and an I² value of 41%, suggesting moderate heterogeneity among the studies.

Further breakdown of the results showed that CBT was effective across various treatment durations. In short-term studies, CBT reduced negative symptoms with an MD of -2.71 (95% CI = -3.18 to -1.61, p < 0.001, I² = 48%). Medium-term treatment showed a reduction of negative symptoms with an MD of -1.80 (95% CI = -2.76 to -0.84, p < 0.001, I² = 29%), while long-term treatment resulted in an MD of -1.70 (95% CI = -2.54 to -0.85, p < 0.001, I² = 0%).

In addition to negative symptoms, CBT also improved overall functioning, with five studies reporting a standardized mean difference (SMD) of 0.38 (95% CI = 0.13 to 0.63, p < 0.05, I² = 0%). Improvements were also noted in social skills, with three studies reporting an SMD of 0.87 (95% CI = 0.58 to 1.16, p < 0.001, I² = 0%) and in social functioning, where three studies reported an SMD of 0.19 (95% CI = 0.03 to 0.36, p < 0.05, I² = 24%).

Quality assessments of the included studies revealed nine studies had a low risk of bias, while four exhibited moderate risk. The GRADE criteria categorized the quality of evidence for negative symptoms as moderate, while overall functioning and social skills were rated as low quality due to concerns about bias and imprecision.

The results underscore the potential of CBT in treating negative symptoms in schizophrenia, an area where traditional antipsychotic medications show limited effectiveness. Many patients experience persistent negative symptoms that hinder their social interactions and daily functioning. CBT may directly address these symptoms by enhancing motivation, emotional regulation, and cognitive restructuring.

Despite these encouraging findings, the study notes that future research is necessary to clarify the mechanisms through which CBT influences negative symptoms. There is a need for more nuanced assessments that differentiate between primary and secondary negative symptoms, as well as studies utilizing neuroimaging to explore the impact of CBT on neural pathways involved in emotional and motivational processing.

In summary, CBT presents a valuable therapy option for individuals with schizophrenia facing negative symptoms. The meta-analysis indicates that CBT can lead to measurable improvements in these symptoms, overall functioning, and social skills, offering hope for more effective treatment strategies in managing schizophrenia.