Go to main contentGo to footer
- 21 September 2022

Obsessive-Compulsive Disorder: Does it rely on genetic or environmental factors?

Understanding the factors that contribute to the development of Obsessive-Compulsive Disorder (OCD) is a crucial step in developing effective prevention and treatment strategies.

Learn more about the genetic and environmental risk factors associated with OCD.

Risk Factors of Obsessive-Compulsive Disorder

Obsessive-Compulsive Disorder (OCD) is a complex and widespread psychiatric condition that affects between 2% and 3% of the population during their lifetime.

Often those who suffer from this disorder discover that other members of their family have dealt with the same syndrome in the past, thus thinking that their symptoms may have a genetic origin. However, scientific studies increasingly highlight the profound impact of various environmental factors on the development of OCD.

So, does Obsessive-Compulsive Disorder depend on genetic or environmental factors? And how do environmental factors affect those with a genetic risk? As of the current state of knowledge, the scientific community agrees that OCD is the result of a complex interaction between genetic and environmental factors. Nonetheless, the precise proportion of influence between these two factors remains partly to be quantified.

The Impact of Genetic Factors in Different Developmental Stages

Some genetic factors appear to have a time-specific impact throughout various developmental stages, potentially involving several age-sensitive genes. However, the environmental risk factors that may pose a greater threat to children differ from those affecting adolescents. Hence, sensitivity to age-related environmental factors might offer dynamic protective effects.

In the case of Obsessive-Compulsive Disorder, scientific studies indicate that up to 80% of symptom stability and persistence can be attributed to genetic factors. Simultaneously, it becomes increasingly evident that environmental factors influence symptom severity with a dynamic effect.

Genetic Predisposition and Environmental Influence

Environmental factors exert a variable impact on individuals. More and more scientific studies suggest that some people may be genetically predisposed to experience stressful events more significantly than others. This predisposition may result from a negative perception of events or a tendency to seek negative experiences. Genetic predisposition can contribute to making a person more vulnerable to the long-term effects of stressful events.

Scientific research continually investigates the effects of the environment on Obsessive-Compulsive Disorder. However, distinguishing these effects from genetic ones can be challenging. Studies focusing on the connections between environmental risk factors and obsessive-compulsive symptoms often rely on self-reports, which can be imprecise and inadequately represent the temporal relationship between traumatic events and symptom onset.

Although there is considerable evidence of the heritability of Obsessive-Compulsive Disorder, some studies suggest a closer balance between genetics and environmental risk, hypothesizing that environmental factors can have an independent impact. These findings support the notion that environmental factors are not merely associated with Obsessive-Compulsive Disorder but may even have a causal effect.

Prenatal Risk Factors

Individuals who have experienced adverse events during the prenatal and perinatal periods are at a higher risk of developing OCD. Typical risk factors during these periods include:

  • Maternal smoking during pregnancy

  • Premature birth

  • Low birth weight

If a person has experienced multiple risk factors, the likelihood of suffering from OCD during their lifetime is even higher. These findings underline the importance of the fetal environment as a potential source of risk or, conversely, protection against the development of Obsessive-Compulsive Disorder.

Risk Factors in Childhood

Events Impacting the Immune System

Some studies have indicated that early impacts on the immune system in the first years of life can contribute to the development of Obsessive-Compulsive Disorder symptoms. Microglia cells ― which are the primary immune cells of the central nervous system ― are crucial for proper brain development. The activation of these cells in the early years of life has been associated with significant brain changes, subsequently affecting mood and cognition, leading to compulsive symptoms.

Streptococcal Infections

Sometimes, symptoms of Obsessive-Compulsive Disorder can appear following unexpected events, such as a bacterial infection. This is the case with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS), a group of pathological conditions in which Obsessive-Compulsive Disorder symptoms suddenly manifest or worsen following streptococcal infections during childhood. In these cases, it is believed that symptoms stem from an exaggerated immune response rather than the infection itself.

Childhood Abuse

Experiences of sexual violence and emotional abuse during childhood are unfortunately common among individuals suffering from OCD. Moreover, a history of such experiences is typically correlated with more severe symptoms. Although a causal relationship has not been established, the presence of childhood abuse experiences significantly correlates with the severity of OCD symptoms, even after the completion of treatment.

Among the different forms of childhood abuse, the one found to be most associated with severe forms of Obsessive-Compulsive Disorder is emotional abuse.


Despite the established evidence of some genetic factors underlying the development of Obsessive-Compulsive Disorder, the exact causes of this disorder are not yet known. Scientific research primarily focuses on the interaction between genetic and environmental factors, which seem to influence each other by interactively contributing to the development of vulnerability to Obsessive-Compulsive Disorder.

A deeper understanding of the developmental mechanisms of Obsessive-Compulsive Disorder could provide valuable insights for the formulation of effective prevention and treatment strategies. Among these, Neuromodulation Therapies emerge as one of the most promising treatment modalities.

Last News