Use of omega-3 PUFA in psychosis, autism spectrum disorders and ADHD
Interest in research into omega 3 polyunsaturated fatty acids (ω-3 PUFA) in the treatment of various mental disorders has increased in recent years. A deficiency in healthy subjects has been reported in attention deficit/hyperactivity disorder (ADHD), depression, schizophrenia and autism spectrum disorders. Of particular note is the observed deficiency in the composition of FAs (including ω-3 and ω-6) in the peripheral tissues of people with schizophrenia in their first episode (thus without having been previously medicated), which is partially normalised with chronic antipsychotic therapy. A deficiency in docosahexaenoic acid (DHA), in red blood cells or serum, has also been reported in psychotic patients in their first episode, patients with schizophrenia and children with ADHD.
Psychotic diseases are generally preceded by a prodromal phase, characterised by various non-specific behavioural and psychological symptoms, functional deterioration, attenuated and intermittent positive symptoms and brief psychotic symptoms. Prospective studies on individuals who later developed psychosis have helped detect potential risk factors and facilitated the use of terms such as ‘ultra-high-risk’, which identifies adolescents and young adults at high risk of fully developing psychotic symptoms; 22-40% of them will have completed the transition within 12 months. Supplementation with ω-3 PUFA has been found to have possible beneficial effects on psychotic symptoms and could have beneficial effects in the prevention of transition to psychosis, severity of symptoms and overall function; this, together with the finding of lower levels of ω-3 and ω-6 in patients with schizophrenia, has lead to the membrane phospholipid hypothesis of schizophrenia. Many epidemiological and observational studies and meta-analyses indicate that fish-oil or ω-3 PUFA consumption is linked to a lower risk of psychosis.
Autism spectrum disorders include a group of conditions related to neurodevelopment, presenting as deteriorating social behaviour, limited communication, repetitive actions and limited interests. The cause is generally genetic, but environmental factors also seem to play an important role. The results of controlled randomised trials and meta-analyses show a small, non-significant beneficial effect for ω-3 PUFA in children with autism disorders. These results lead to the recommendation of its use as adjuvant therapy, supplementing other therapies.
Evidence from observational studies indicate a relationship between the symptoms of ADHD and blood ω-3 PUFA levels. Numerous randomised controlled intervention studies have been conducted to investigate the efficacy of ω-3 PUFA supplementation on the symptoms of ADHD, most using it as monotherapy (although some also added classic pharmacological treatment). Several such studies have reported beneficial effects, but on different symptoms (attention, hyperactivity/impulsiveness, school performance, etc.).
The fact that randomised studies in different psychiatric disorders fail to always obtain results in the same line is probably due to differences in sample size, different selection criteria, different subtypes and doses of ω-3 PUFA, different neuropsychological tests and scales used and the differing durations for treatment. This also occurs with studies on ADHD.
With regard to autism spectrum disorders, the evidence is even more limited. Furthermore, study periods of at least one year are required to demonstrate behavioural changes in response to supplementation with ω-3 PUFA.
Prospective interventional clinical trials, with large samples, using therapeutic doses of ω-3 PUFA and new research methodologies are required.
Even so, overall, the results seem to indicate a beneficial effect with ω-3 PUFA in psychotic disorders, autism spectrum disorders and ADHD.
Agostoni C, Nobile M, Ciappolino V, Delvecchio G, Tesei A, Turolo S, et al. The Role of Omega-3 Fatty Acids in Developmental Psychopathology: A Systematic Review on Early Psychosis, Autism, and ADHD. Int J Mol Sci. 2017;18(12).