A team of scientists from the University of Granada (UGR), part of the Mind, Brain and Behavior Research Center (CIMCYC), has prepared a report for the Directorate-General for Traffic (DGT) titled 'Psychophysical conditions of drivers with mood and anxiety disorders' (‘Condiciones psicofísicas de los conductores con trastorno de estados de ánimo y ansiedad’), a comprehensive review analyzing the relationship between mental health, pharmacological treatments and road safety.
The authors warn that although mental disorders affect approximately 34% of the Spanish population, only 0.63% of those who renew their driver's license report suffering from an illness of this type to Driver Recognition Centers (CRC), indicating a possible underestimation of the problem.
The report notes that mental illnesses are associated with a higher risk of traffic accidents. Drivers with these disorders present a relative risk of accident rates 72% higher than the population without these pathologies.
Analyses indicate that major depression can impair executive functions fundamental for driving, such as sustained attention, reaction speed and decision-making. In people with anxiety, problems with attentional control and decreased self-efficacy at the wheel have been observed, while in bipolar disorder, alterations in attention and information processing persist, even in phases of clinical remission.
Likewise, experiments with simulators and road tests suggest that people with partially remitted depression can recover driving capacities similar to those of healthy drivers, provided they maintain clinical stability and adequate psychosocial functionality.
The role of medication in road safety
One of the most relevant aspects is the analysis of the impact of certain psychotropic drugs. The researchers stress that some antidepressants with sedative properties, as well as benzodiazepines and hypnotics, temporarily alter the psychomotor capacities necessary to drive safely.
Detected effects include drowsiness, decreased alertness, psychomotor slowing, coordination problems and increased irregular vehicle movements. The study points out that certain sedative antidepressants increase lateral vehicle deviation—a measure known as Standard Deviation of Lateral Position (SDLP)—to levels comparable to those observed in drivers with high blood alcohol levels.
The review concludes that the combination of antidepressants and benzodiazepines enhances driving impairment and increases the risk of accidents, especially in young drivers and older people. Conversely, non-sedating antidepressants do not seem to produce significant alterations in road performance.
However, the authors understand that pharmacological treatment should not automatically be interpreted as a contraindication for driving. The report insists that fitness must be assessed individually, taking into account the patient's global clinical state, their adaptation to treatment and specialized medical follow-up.
Toward a more precise and humane evaluation
The study reviews Spanish regulations on psychophysical fitness for driving. The General Drivers Regulations establish that severe mood disorders are incompatible with driving, except with a favorable clinical report, leading in certain cases to licenses with reduced validity and periodic reviews.
The researchers consider it necessary to reinforce evaluation systems through standardized psychological screening tools, neuropsychological tests and individualized functional evaluations, especially in professional drivers and older people.
"The research advocates for a multidisciplinary approach that combines prevention, mental health and road safety, avoiding the stigmatization of people with psychological disorders and promoting awareness campaigns on the consumption of psychotropic drugs and their possible effects," explains psychology professor Cándida Castro Ramírez, the scientist who signs this work.
According to the CIMCYC researcher, "road safety cannot be addressed exclusively from technical factors, but also requires considering emotional, cognitive, labor and psychosocial variables."
The study was led by Cándida Castro Ramírez, alongside David A. Salazar-Frías, Antonia P. Pacheco-Unguetti and María Blasa Sánchez Barrera.
Systematic review with PRISMA methodology
The research includes a systematic review registered in PROSPERO (CRD420251023655) and developed according to international PRISMA recommendations. To do this, the team studied scientific publications indexed between 2015 and 2025 in databases such as Web of Science, Scopus, PubMed, PsycINFO, ProQuest and Medline/CINAHL.
In total, 288 scientific studies were located, of which 31 were finally included after applying criteria of methodological quality and independent evaluation by specialized researchers.
Reference:
Castro, C., Salazar-Frías, D.A., Pacheco-Unguetti, A.P. & Sánchez-Barrera, M.B. (2025). Estudio de avances científicos sobre las condiciones psicofísicas de los conductores con trastorno de estados de ánimo y de ansiedad. DGT.
https://www.dgt.es/export/sites/web-DGT/.galleries/downloads/conoce_la_dgt/que-hacemos/conocimiento-e-investigacion/Informe-Condiciones-Psicofisicas_v_final__acc_meta_ok.pdf
Contact:
Cándida Castro Ramírez - @email