Schizophrenia is a psychological disorder that is estimated to affect 300,000 Canadians, and the American numbers are staggering. Can the amino acid L-lysine help?
Globally, up to 0.7 per cent of the population is diagnosed with the mental disorder. Characterized by impairment in an individual’s ability to think clearly and manage emotions, symptoms of schizophrenia can include delusions, paranoia, disorganized speech and thought processes, and auditory hallucinations. Individuals living with the disorder may encounter significant social or occupational obstacles.
Because both environmental and genetic factors contribute to the development of schizophrenia, researchers at the Centre for Addiction and Mental Health in Toronto examined if L-lysine could be an effective adjunctive treatment for the disorder.
Previous studies suggest that the brain’s nitric oxide signalling system can be a contributing factor in developing schizophrenia. Since L-lysine is an amino acid that interferes with nitric oxide production, researchers Caroline Wass et al. hypothesized that adjunctive L-lysine treatment would alleviate the severity of symptoms and improve cognition in persons living with schizophrenia.
Lysine is an amino acid that can be readily absorbed from the intestine and has high brain penetration. Previous research have tested lysine as treatment for osteoporosis and recurrent herpes infection.
The effect of L-lysine on the symptoms of schizophrenia
For the single-blinded, crossover study ten patients with schizophrenia were used. Six grams of L-lysine or a placebo was administered daily to the participants as an add-on to their usual antipsychotic medication. The treatment took the form of L-lysine dissolved into a soft drink, or only the soft drink alone for the placebo group.
The experimental trial continued over a period of four weeks and then treatment crossed over for another four weeks. Clinical assessments of symptom severity and functional outcome were made at baseline, after four weeks and at the end of the trial after eight weeks. Blood samples and cognitive performance tests were also taken.
After evaluating the data, researchers Wass et al. found that L-lysine treatments significantly increased the concentration of the amino acid in the blood without causing adverse side effects. There was significant decrease in the measure for psychosis severity, especially the symptoms of delusion and paranoia. Problem solving abilities and cognitive flexibility were also significantly improved after L-lysine treatment.
Based on these results, the researchers believe that L-lysine can have valuable potential as treatment for schizophrenia.