Insomnia comorbid to Parkinson's disease Part II: Therapeutic approaches.

Insomnia is four times more frequent in patients with Parkinson's disease (PD) than in the general population. In PD, insomnia is associated with a very significant decrease in quality of life and has deleterious consequences on both patients' and caregivers' health. When insomnia is comorbid to PD, the main therapeutic response is the prescription of benzodiazepines or related drugs. As in the general population, these sedative-hypnotic molecules have very low efficacy in PD and are associated with adverse effects. They are highly addictive and are also associated with drowsiness, a risk of falling and decreased life expectancy. These side effects may in themselves be symptoms associated with PD in the absence of insomnia. In this clinical context, it is clear that sedative-hypnotic drugs are likely to potentiate these clinical symptoms in PD. We recently documented that insomnia disorder comorbid to PD is associated with the classic psychological factors that perpetuate insomnia in neurologically disease-free individuals with insomnia. These results enabled us to emphasise that target-oriented interventions, such as cognitive-behavioural therapy for chronic insomnia (CBT-i), should be considered as a treatment for insomnia comorbid to PD. As a reminder, for decades CBT-i has been considered to be the most effective first-line treatment for the management of chronic insomnia, whether or not it is associated with a comorbidity. In this context, we demonstrated the acceptability of CBT-i in the treatment of insomnia comorbid to PD and its effectiveness for the management of noctural and diurnal symptoms of insomnia associated with this neurological condition. The objective of this paper is to raise awareness among health professionals of the relevance of psychological therapies (mostly CBT) for insomnia in PD. Unlike drug treatments, these therapies are safe for patients who are already weakened by PD itself.