Acquired Sociopathy and Frontotemporal Dementia

Abstract

Background: It is not understood why some patients withfrontotemporal dementia (FTD) manifest sociopathic behavior. Objective: To examine the prevalence and characteristics of sociopathic behavior in FTD patients as compared to those with Alzheimer’s disease (AD). Methods and Participants: We surveyed a group of FTD patients and a group of AD patients for sociopathic behavior, evaluated the characteristics surrounding their acts, and compared the groups on neuropsychological tests and functional neuroimaging. Twenty-eight outpatients with FTD (15 men, 13 women; 61.9 ± 7.1 years; Mini-Mental State Examination score 23.6 ± 8.1) were compared with 28 patients with clinically probable AD (13 men, 15 women; 66.1 ± 9.2 years; Mini-Mental State Examination score 21.3 ± 5.3). Main outcome measures included: (a) the prevalence of sociopathic acts; (b) a structured interview; (c) neuropsychological tests including the Frontal Assessment Battery, and (d) clinically obtained positron emission tomography or single photon emission tomography scans. Results: Sixteen (57%) of the FTD patients had sociopathic behavior compared to two (7%) of the AD patients (χ² = 13.84, p < 0.001). Sociopathic acts among FTD patients included unsolicited sexual acts, traffic violations, physical assaults, and other unacceptable behaviors. On interview, the FTD patients with sociopathic acts were aware of their behavior and knew that it was wrong but could not prevent themselves from acting impulsively. They claimed subsequent remorse, but they did not act on it or show concern for the consequences. Among FTD patients with sociopathy, neuropsychological assessment showed impaired motor inhibition, and functional neuroimaging showed right frontotemporal involvement. Conclusion: The results suggest that sociopathy in FTD results from a combination of diminished emotional concern for the consequences of their acts and disinhibition consequent to right frontotemporal dysfunction. In many jurisdictions, FTD patients with sociopathy would not pass legal criteria for ‘not guilty by reason of insanity’.

An Investigation of Moral Judgement in Frontotemporal Dementia

“…2 Prior research indicates that sociopathic acts are prominent among patients with FTD. 3,4 Antisocial behavior occurs in more than half of patients with FTD and includes unsolicited sexual acts, traffic violations, stealing, and physical assaults. 3,4 Other investigators have also described shoplifting, 16,17 inappropriate sexual behavior, 4,18 acts of violence, 16 and even pedophilia.…”

“…1,2 The alterations in social behavior usually involve a loss of social tact and propriety, but may include frankly sociopathic acts such as unsolicited sexual behavior, traffic violations, physical assaults, stealing, breaking and entering, and even paraphilias. [3][4][5] Patients with FTD have disturbances of moral behavior or the ability to follow ethical and accepted rules and norms. The transgression of social norms is a core diagnostic feature of FTD.…”

Structural brain abnormalities in psychopaths—a review

“…Finally, there is an increased frequency of psychopathic and violent behavior in well known organic brain diseases such as fronto-temporal dementia (including Pick's disease; Mendez, Chen, Shapira, & Miller, 2005), which stresses the association between fronto-temporal brain disease and psychopathic behavior.…”

Behavioural variant frontotemporal dementia: Clinical and therapeutic approaches

“…18,19 Other studies have described patients with sociopathic and deviant behaviours such as violating traffic regulations or assaulting others physically. 20,21 Perseveration, with repetitive and stereotyped behaviours (tendency to repeat movements, sentences, stories, or jokes), is another characteristic finding. These patients usually present rigidity and limited mental flexibility, therefore lack of adaptation to new situations or routines is frequent.…”