10 Neurological Abnormalities in Psychopaths (Neurotransmitter and Brain Region Differences in Psychopaths/AntiSocial PD)

Psychopathy is a disorder characterized by a prominent lack of empathy, remorse or guilt; and especially a relative disregard for legal or societal rules or expectations... 'Psychopaths' are also more viable and generally more intelligent than sociopaths (sociopaths are generally more impulsive and less cunning). The big question over the years; is if there is a neurobiological perspective/etiology to psychopathy. 

Research has shown the following major points/alterations to be directly involved.

• Damage to the medial Prefrontal Cortex (mPFC); common with head trauma, or lack of oxygen supply upon Birth. This can also happen to an extent with neurotoxicity and / or heavy metal poisoning. (1) (2) (3) (4)
• Elevated Copper levels. (Copper acts as a CNS stimulant; and excess can wear out the adrenal glands) Some psychopaths are noted with low heart rate and moderately elevated blood pressure. (5) (6)
• Elevated Cadmium and / or Lead; which leads to shrinkage of both cortical neurons and amygdala nuclei - two prerequisite changes necessary for loss of emotional capacity and self-control. (7) (8)
• Low CNS Activity; particularly a low heart rate in many 'extreme' psychopaths - those inclined to Rape and thrill seeking tend to have a lower heart rate and thus oxygen supply...the impaired oxygen leads to lack of consideration of consequences. (9)
• Low heart rate may be related to low levels of cyclic Adenosine monoPhosphate (cAMP) - which regulates / increases sympathetic nervous system activity. Thus , some* Psychopaths may have low dopamine D1 receptor activation as well as low histamine H2 or beta-adrenergic activation. There may also be central reductions in CREB-dependent reactions.  (10) (11) (12)
• Decreased dopamine D2 receptor concentrations in the meso-cortical-limbic projections and decreased overall Dopamine in the prefrontal cortex is noted in psychopathy. However, in the Striatum, dopamine may be elevated and this is in part, due to decreased levels of regulatory 'dopamine D2 autoreceptors'. (13) (14)
• Low levels of the neuropeptide Oxytocin (hormone of trust, love and sexual motivation). (15)
• Low levels of GABA and Acetylcholine may lead to Aggressive behavior . Though, it's possible that some psychopaths may have high levels of GABA. Hence the fearlessness. (16) (17)
• Elevated serotonin is found in obsessive-compulsive, calculating Psychopaths; and this confers the lack of or distorted dopamine function leading to lack of empathy, elevated serotonin is associated with instrumental crimes/objective oriented crimes and is also found in some Cult leaders. (18) (19) (20) (21)  however, lower serotonin is found in impulsive criminals as opposed to premeditated criminals whom have higher levels.
• NeuroEndocrine abnormalties; hypothalamic activity may be either excessive or under-active; depending on the type. Impulsive, Sadistic or those afflicted with Satyriasis tend to have abnormally high hypothalamic activity either in the context of increased neuronal connections or larger overall nerve fibers (22) (23) - however, calculating, cold, dysphoric or otherwise 'mastermind' type criminals might have, on average, lower/low-ish levels of hypothalamic activity. (24)   The increased hypothalamic activity in Rapists and sexual sadists may be related to increased ACTH secretion from the adrenal gland and / or lack of negative feedback and the decreased HPA axis in 'callous' 'cold' criminals may be related to decreased bottom-region HPA activity. This could also have to do with lead poisoning and other heavy metals which disrupt the HPA axis.