Apomorphine induced alteration in corneofundal potentials in depression

Area of Science:

• Neuroscience
• Psychiatry
• Ophthalmology

Background:

• The role of dopamine in mood regulation is debated.
• Previous methods using neuroendocrine responses have yielded inconclusive results for affective disorders.
• Retinal dopamine function may offer a more reliable indicator.

Purpose of the Study:

• To investigate dopamine function in depressed patients using retinal electrical responses.
• To compare neuroendocrine and ocular responses to apomorphine challenge in depressed patients and controls.

Main Methods:

• 12 depressed patients and 12 healthy controls received a 0.75 mg subcutaneous apomorphine challenge.
• Neuroendocrine (prolactin, growth hormone) and ocular (light-dark retinal potentials) measures were recorded before and after the challenge.

Main Results:

• Apomorphine increased retinal potentials in depressed patients but decreased them in controls (p < 0.002).
• No significant baseline differences or group differences in prolactin or growth hormone levels were observed post-challenge.

Conclusions:

• Retinal electrical responses show altered dopamine sensitivity in depression.
• The retina may be a more sensitive biomarker for dopamine abnormalities in depressive illness than neuroendocrine measures.