Effectiveness of Psychotherapies and Psychotropic Drugs against Mental Illness

Effectiveness of Psychotherapies and Psychotropic Drugs against Mental Illness Contents Psychotherapies for Depression This book analyzes the results of numerous clinical studies conducted over the past forty years to evaluate the effectiveness of psychotherapies and psychotropic drugs against mental illness. This evaluation was conducted for each study by creating samples of people with mental illness undergoing psychotherapy or psychotropic drugs, and samples of people with mental illness not receiving psychotherapy or psychotropic drugs (control groups). The studies were conducted through interviews with self-administered or clinician-completed scales. The effect size was then statistically measured, often expressed as Hedges' g or Cohen's d. This measure indicates, for example, by how many standard deviations the psychotherapy group improved compared to the control group. The interpretation of g is: `g ≈ 0.2` → small effect `g ≈ 0.5` → medium `g ≈ 0.8` → large Another type of measurement is the Odds Ratio (OR), which is useful for interpreting the probability of clinical success, or better yet, of achieving a positive outcome (treatment response) compared to control groups. The interpretation of OR is: OR = 1 → no difference OR > 1 → treatment increases positive response compared to the control group OR < 1 → treatment worsens the control Example: OR = 2 → probability of positive response doubles OR = 1.5 → +50% probability So if in a group of 10 people, 3 recover and 7 do not, the OR is 3/7 (0.42). In addition to g and OR, the Risk Ratio (RR) is also measured, which compares the probability (the risk) of an event (such as recovery) occurring in the treated group compared to the control group. RR = 1 → no difference RR > 1 → treatment increases the probability of a positive response compared to the control group RR < 1 → treatment is less likely than the control group So if the treatment group has a 30% probability of remission and the control group a 10% probability, the RR is 3 (30/10), meaning the treatment group is three times more likely to be cured. The calculations of g, OR, and RR are performed using meta-analysis, which is a statistical research procedure that integrates and synthesizes the results of multiple clinical trials to answer a specific research question. Rather than relying on the results of a single study, meta-analysis combines data from many studies to provide a more robust and precise estimate of a treatment's effectiveness. In short, meta-analysis allows us to move from "many small results" to "a solid conclusion," helping to establish, for example, whether psychotherapy is as effective as medication or whether it produces long-lasting benefits. Finally, network meta-analysis is an advanced statistical methodology that allows for the simultaneous comparison of multiple treatments (interventions) within a single model, even when they have not been directly compared in clinical trials. While a traditional meta-analysis typically compares two options (e.g., a drug versus a placebo), NMA is used to compare and rank, for example, numerous psychotropic drugs and a placebo. One of the main advantages of NMA is that it allows for the creation of a ranking that indicates the probability of a drug being the best for a given outcome. Implementation in R The meta-analyses in this book are performed in the R programming language, using the RStudio software and downloading the "dplyr, meta, and metafor" packages and datasets provided by researchers, each containing a clinical study and its associated variables in each row. Table of Contents Psychotherapies: Psychotherapies for depression 75% May 17, 2026 Psychotherapies for anxiety 75% May 17, 2026 Psychotherapies for social anxiety 75% May 17, 2026 Psychotherapies for panic disorder 75% May 17, 2026 Psychotherapies for psychosis 75% May 17, 2026 Psychotherapies for eating disorders 75% May 17, 2026 Psychotherapies for suicide prevention 75% May 17, 2026 Psychotropic drugs: Antidepressants 75% May 17, 2026 Psilocybin for depression 75% May 17, 2026 Psychology E 25%