Patients with functional neurological disorders demonstrate higher levels of depression and alexithymia – in addition to signs of an avoidant attachment style – compared with those with other neurological disorders and healthy controls, investigators report.
The pathological mechanism of functional neurological disorders (FND) remains poorly understood, but current models include both psychological and environmental factors, Sofia Cuoco, PhD, and colleagues wrote in a study published in the Journal of Psychosomatic Research.
Previous studies have suggested a relationship between attachment styles (AS) and psychiatric symptoms in FND patients but most have been limited to the FND population, noted Dr. Cuoco, of the University of Salerno, Italy, and colleagues. In FND, “it is unclear to what extent psychiatric features are explained by AS per se or are part of the FND spectrum,” they said.
To conduct the study, the investigators recruited 46 patients with FND, 34 patients with neurological disorders (ND) and 30 healthy controls. Demographic characteristics, including age, education, and gender, were similar among the groups. Overall, depression and alexithymia were significantly more prevalent in the FND group, compared with the other groups. Anxiety was more common in the FND group, compared with healthy controls, but similar compared with the ND group. Patients in the FND group reported significantly lower quality of life, compared with those in the other groups.
In a multivariate analysis aimed at examining AS and psychiatric features, the researchers found that the Experiences in Close Relationships–Revised questionnaire avoidance, Beck Depression Inventory, Somatic Affective, and the 20-item Toronto Alexithymia Scale Difficulty Identifying Feelings scale (TAS-20 Difficulty Identifying Feelings) were significant predictors of FND and accounted for about half of the variance.
The researchers also compared FND to functional seizures, and found that the TAS-20 Difficulty Identifying Feelings scale, the Hamilton Anxiety Scale–Anxiety, and female gender were significant predictors of functional seizures.
The results were mainly in line with those from previous studies, the researchers said. However, than ND, which might suggest that these psychiatric features would not be merely reactive to physical symptoms,” they noted.
The study findings were limited by several factors, including the absence of systematic interviews for personality disorders or traits, monitoring psychotropic medications, and conducting formal psychiatric assessments, the researchers noted. Other limitations include the heterogenous study population and absence of data on symptom severity, history of trauma, or other factors that might contributed to FND, they said.
However, the results suggest that avoidant AS might play an important role in the occurrence of psychiatric features in FND patients and should be considered in managing these conditions. More research is needed to explore the impact of attachment on pathophysiology with more complex instruments, such as the Adult Attachment Interview, Dr. Cuoco and colleagues said.
The study received no outside funding, and the researchers disclosed no financial conflicts.