From:  Cognitive impairment after traumatic brain injury: mechanisms, clinical profiles, and implications for cognitive remediation and functional recovery

 Psychiatric manifestations following TBI and their interactions with cognitive impairment.

Psychiatric symptomEstimated prevalenceProposed mechanismsImpact on cognitive function Relevant references
DepressionHigh prevalence; persistent low mood, anhedonia, fatigue, sleep disturbances, reduced motivationChronic neuroinflammation; monoamine dysregulation; disrupted mood-regulating neural circuitsExacerbates attention, memory, and executive deficits; further impairs functional recovery and QoL[14, 7476, 83]
Anxiety disordersCommon; generalized anxiety, panic symptomsLimbic and prefrontal structural/functional changes; dysregulated stress response systemsIncreases distractibility; reduces cognitive efficiency; compounds executive and attentional deficits[83, 91]
Post-traumatic stress disorder (PTSD)Substantial comorbidity; intrusive memories, avoidance, hyperarousal, negative moodDysregulated HPA axis; altered amygdala-prefrontal circuitryInteracts with attention and memory impairments; diminishes functional outcomes[92, 93]
Irritability/Aggression/Emotional dysregulationFrequent; rapid mood shifts, impulsivity, low frustration toleranceDisruption of fronto-limbic and orbitofrontal networksLeads to social isolation, interpersonal difficulties, caregiver burden; co-occurs with depression/anxiety[86, 94]
Cognitive-psychiatric interactionBidirectional interplay between cognitive and psychiatric symptomsExecutive dysfunction, slowed processing, attentional deficits impair emotional regulationPsychiatric disorders exacerbate cognitive deficits, creating a cycle affecting functional independence and QoL[86]

The table summarizes the major psychiatric symptoms observed after traumatic brain injury (TBI), including prevalence, clinical features, proposed neurobiological mechanisms, and their impact on cognitive function and daily functioning. The bidirectional interactions between cognitive deficits and psychiatric disturbances are highlighted, emphasizing the importance of integrated assessment and rehabilitation strategies. HPA: hypothalamic-pituitary-adrenal; QoL: quality of life.