Figure 1.
Post-traumatic stress disorder has been associated with observed disparities from control over multiple biological levels of detail. Post-traumatic stress disorder (PTSD) has been associated with allelic variations at multiple genetic loci; DNA methylation patterns and gene transcription patterns have also been reported to differ with PTSD status and/or stress exposure. Disparate levels of multiple hormones and other biochemicals have been observed in saliva, blood, or cerebrospinal fluid (CSF), and differences in autonomic reactivity to either trauma-related or -unrelated stimuli have been suggested via measures of electromyography (EMG), skin conductance, and heart rate. Brain regions additionally examined by proton magnetic resonance spectroscopy (1H MRS), such as the prefrontal cortex, hippocampus, and amygdala, have demonstrated abnormalities in volume, neurotransmitter receptor binding, and patterns of blood oxygen-level-dependent (BOLD) contrast in PTSD. In assessing these reported differences, as in 1H-MRS findings, it should be noted that depending on study design, biological differences observed between PTSD patients and control may elucidate predisposition to develop PTSD, effect of trauma exposure or PTSD pathology, or all of the above. TLS: total life stress; CRH: corticotrophin-releasing hormone; ACTH: adrenocorticotropic hormone; TSH: thyroid-stimulating hormone; AVP: arginine vasopressin; AlloP: allopregnanolone; CSF: cerebrospinal fluid; EMG: electromyogram; rCBF: regional cerebral blood flow; ACC: anterior cingulate cortex; 5-HT: 5-hydroxytryptamine (serotonin); CB1R: cannabinoid receptor type 1; rACC: rostral anterior cingulate cortex; dACC: dorsal anterior cingulate cortex. This figure was created with BioRender.com.