Excessive intake of saturated fatty acids and physiologically imbalanced amino acids worsens the patient’s psychotic condition, creating the risk of developing psychosis and other comorbidities. Therefore, to ensure the optimal amount of amino acids and improve the psychotic state, pea protein isolate is an alternative to nutritional supplementation. The aim of the study was to analyse the amino acid profile of pea protein isolates and their solubility to evaluate their potential for the development of beverages for patients with psychiatric disorders. In the study, the amino acid profile analysis of organic and conventional pea protein isolates was performed using high performance liquid chromatography mass spectrometry. To evaluate solubility, pea protein isolates were treated in an ultrasonic bath and at different pH concentrations. The results showed that organic pea protein isolate showed a higher composition of essential amino acids (41.27%) and semi-essential amino acids (8.37%) than conventional pea protein isolate. Organic pea protein isolate was able to provide a more appropriate amino acid composition to meet the amino acid needs of patients with psychiatric disorders. Organic and conventional pea protein isolates had higher solubility in the ultrasonic bath of 20 min and in the alkaline environment. The solubility between the two pea protein isolates was not significantly different, but the ultrasonic bath treatment and different pH concentrations were significant, which gave insight and further application in beverage production.