Depression and anxiety disorders are among the leading causes of disability worldwide, particularly affecting young adults. These disorders have traditionally been diagnosed based on clinical criteria; however, increasing evidence suggests that structural brain changes play a crucial role in their pathophysiology.

Magnetic Resonance Imaging (MRI) has emerged as a powerful tool for evaluating brain morphology. Structural MRI studies have demonstrated alterations in key brain regions such as the hippocampus, amygdala, and prefrontal cortex in individuals with depression and anxiety. These regions are involved in emotional regulation, memory, and stress response.

Previous studies have reported reduced hippocampal volume in patients with major depressive disorder, likely due to chronic stress and elevated cortisol levels. Similarly, hyperactivity and structural enlargement of the amygdala have been associated with anxiety disorders. Changes in prefrontal cortex thickness have also been linked to impaired emotional regulation.

Despite growing global evidence, there is limited data from Indian populations exploring these associations. The present study aims to assess structural brain correlates using MRI and their relationship with depression and anxiety among young adults

Study Design and Setting

A hospital-based cross-sectional study conducted over a period of 1 year in the Department of Radiodiagnosis in collaboration with Psychiatry.

Study Population

Young adults aged 18–30 years attending outpatient departments.

Sample Size

A total of 120 participants were included.

Inclusion Criteria

• Age 18–30 years
• Willing to participate
• No contraindication to MRI

Exclusion Criteria

• Known neurological disorders
• History of head injury
• Psychiatric treatment history
• Substance abuse

Assessment Tools

1. PHQ-9 for depression assessment
2. GAD-7 for anxiety assessment

MRI Protocol

• 5 Tesla MRI scanner
• Sequences: T1-weighted, T2-weighted, FLAIR
• Volumetric analysis of:
  • Hippocampus
  • Amygdala
  • Prefrontal cortex thickness

Statistical Analysis

• SPSS version 25
• Pearson correlation
• Independent t-test
  • p < 0.05 considered significant

A total of 120 young adults were included in the present study. The mean age of the participants was 23 ± 3 years, indicating that the study population primarily consisted of individuals in early adulthood. Among them, females constituted 52% while males accounted for 48%, reflecting a nearly equal gender distribution. This balanced representation allowed for meaningful comparison of psychological and radiological parameters across genders.

With respect to psychological assessment, the prevalence of depression among the participants was found to be 40%, while anxiety was observed in 45% of individuals. These findings suggest a considerable burden of mental health issues in this age group. The assessment was carried out using standardized tools, and a substantial proportion of participants scored in the moderate to severe range, indicating clinically significant symptoms requiring attention.

MRI brain findings revealed distinct structural differences associated with depression and anxiety. Participants with higher depression scores demonstrated a significant reduction in hippocampal volume (p < 0.01). This suggests that hippocampal atrophy may be an important structural correlate of depressive symptoms. Similarly, individuals with higher anxiety scores showed a significant increase in amygdala volume (p < 0.05), indicating a possible link between amygdala enlargement and heightened emotional reactivity. In addition, reduced thickness of the prefrontal cortex was observed in participants with higher PHQ-9 scores, suggesting impaired executive function and emotional regulation.

Further analysis using correlation methods provided additional insights into the relationship between brain structure and psychological parameters. A moderate negative correlation was observed between hippocampal volume and PHQ-9 scores (r = -0.52), indicating that higher levels of depression were associated with smaller hippocampal size. Conversely, a positive correlation was found between amygdala volume and GAD-7 scores (r = 0.44), suggesting that increased anxiety levels were associated with larger amygdala volume. Additionally, prefrontal cortex thickness showed a negative correlation with stress levels, implying that individuals experiencing higher stress tended to have reduced cortical thickness in this region.

Overall, the results highlight significant associations between structural brain changes and psychological conditions such as depression and anxiety. These findings support the role of neuroimaging in identifying biological correlates of mental health disorders and provide valuable insights into the neuroanatomical basis of these conditions

The present study demonstrates significant structural brain alterations associated with depression and anxiety among young adults. Reduced hippocampal volume observed in this study aligns with previous research suggesting that chronic stress and elevated glucocorticoid levels may lead to hippocampal atrophy. The hippocampus plays a critical role in memory and emotional regulation, and its structural impairment is strongly linked to depressive symptoms.

The finding of increased amygdala volume among individuals with higher anxiety scores is also consistent with earlier studies. The amygdala is a key structure involved in fear processing and emotional responses, and its hyperactivity and structural changes have been widely reported in anxiety disorders.

Additionally, reduced prefrontal cortex thickness observed in this study supports the hypothesis of impaired executive function and emotional regulation in depression. The prefrontal cortex is responsible for higher cognitive processes, and its dysfunction may contribute to the persistence of negative thoughts and mood disturbances.

The correlations identified in this study further reinforce the relationship between brain structure and psychological symptoms. These findings highlight the potential role of MRI as a supportive tool in understanding the neurobiological basis of psychiatric conditions,

MRI brain imaging reveals significant structural correlates of depression and anxiety, particularly involving the hippocampus, amygdala, and prefrontal cortex. These findings emphasize the importance of integrating neuroimaging with clinical assessment for better understanding and management of psychiatric disorders.

Limitations

• Small sample size
• Cross-sectional design
• Lack of longitudinal follow-up

Recommendations

• Larger multicentric studies
• Inclusion of functional MRI
• Longitudinal research for causal inference

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