Meeting abstract

https://doi.org/10.24869/spsih.2026.356

Light Therapy in the Treatment of Depression Following Traumatic Brain Injury

Biljana Kosanović Rajačić ; University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia *
Marina Šagud ; University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
Marija Božićević ; University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
Sonja Udovičić ; University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia

* Corresponding author.

Abstract

Introduction: The pathophysiology of traumatic
brain injury is divided into primary injury, as a
consequence of direct mechanical force acting
on brain tissue, and secondary injury, which develops
gradually after the initial trauma and is
amenable to therapeutic intervention. The mechanisms
include excitotoxicity, oxidative stress,
blood–brain barrier disruption, edema, ischemia,
and neuroinflammation, with chronic activation
of microglia and astrocytes and increased release
of the proinflammatory cytokines TNF-α and IL-
6. After traumatic brain injury, sleep disorders
develop in 40–50% and depression in 30–40%
of patients. Psychosocial factors are also important
for long-term mood and sleep disturbances.
Phototherapy exerts an antidepressant effect via
intrinsically photosensitive retinal ganglion cells
(ipRGCs), which contain the photopigment melanopsin. Impulses are transmitted along neural
pathways to the suprachiasmatic nucleus of the
hypothalamus and to other brain structures involved
in the regulation of circadian rhythm and
mood, including the perihabenular nucleus of the
thalamus and the lateral habenula of the epithalamus.
Case report: Patient A.A. (56 years) has been
in psychiatric treatment since being injured in a
traffic accident in 2002, in which she sustained
polytrauma with head injury, and has been followed
in our outpatient clinic for one year with a
diagnosis of organic affective disorder. Brain MRI
shows a post-traumatic lesion in the right temporal
and hippocampal regions. Neuropsychological
testing reveals cognitive and behavioral
deviations consistent with an organic etiology,
while at the level of personality and behavior
there is pronounced depressive symptomatology
and frontal-type personality change. Treatment
with mirtazapine and clonazepam regulated sleep
and reduced anxiety, but low mood, lack of motivation,
forgetfulness, and occasional irritability
persisted. The patient was included in morning
phototherapy sessions over four weeks, and clinical
improvement in the form of more stable mood
and strengthened volitional dynamics was monitored
with the HAMD-17 and MADRS rating
scales. Conclusion: A growing body of evidence
shows that mood and sleep disorders can persist
for more than 20 years after damage to brain parenchyma.
Morning phototherapy is a low-risk
and well-tolerated approach in the treatment of
depression as a neuropsychiatric consequence of
traumatic brain injury.

Keywords

traumatic brain injury; depression; phototherapy; neuroinflammation; IL-6

Hrčak ID:

353118

URI

https://hrcak.srce.hr/353118

Publication date:

15.6.2026.

Article data in other languages: croatian

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