Acquired sociopathy and frontotemporal dementia

Area of Science:

• Neuroscience
• Behavioral Neurology
• Psychiatry

Background:

• The underlying reasons for sociopathic behavior in some frontotemporal dementia (FTD) patients remain unclear.
• Sociopathy is characterized by a disregard for others' rights and social norms.

Purpose of the Study:

• To determine the prevalence and characteristics of sociopathic behavior in FTD patients.
• To compare sociopathic behavior in FTD patients with that observed in Alzheimer's disease (AD) patients.
• To investigate the neuropsychological and neuroimaging correlates of sociopathy in FTD.

Main Methods:

• A comparative study involving 28 FTD outpatients and 28 AD outpatients.
• Assessment included surveys for sociopathic behavior, structured interviews, neuropsychological testing (including Frontal Assessment Battery), and functional neuroimaging (PET/SPECT scans).
• Mini-Mental State Examination (MMSE) scores were recorded for both groups.

Main Results:

• A significantly higher prevalence of sociopathic behavior was found in FTD patients (57%) compared to AD patients (7%) (p<0.001).
• Sociopathic acts in FTD included sexual offenses, traffic violations, and physical assaults.
• FTD patients with sociopathy were aware of their actions but exhibited impaired motor inhibition and right frontotemporal dysfunction.

Conclusions:

• Sociopathy in FTD is linked to reduced emotional concern and disinhibition resulting from right frontotemporal dysfunction.
• These findings suggest that FTD patients exhibiting sociopathy may not meet legal criteria for 'not guilty by reason of insanity' in many jurisdictions.
• Further research is needed to understand the complex interplay between FTD, sociopathy, and legal culpability.