Fører søvnforstyrrelser til kognitiv svikt hos pasienter med schizofreni eller bipolar lidelse?

Søvnforstyrrelser og kognitive svikt opptrer hyppig ved psykiske lidelser, og dette har negativ effekt på funksjon og livskvalitet. I denne studien har forskere fra Oslo universitetssykehus og Universitetet i Oslo undersøkt om søvnforstyrrelser er relatert til kognitive forstyrrelser hos pasienter med schizofreni eller bipolar lidelse, om dette varierer mellom ulike søvnforstyrrelser (insomni, hypersomni eller forsinket søvnfaselidelse) og til slutt om dette forholdet er forskjellig mellom syke og en frisk kontrollgruppe. Resultatene viste at behandlingsforløp og kognitive funksjoner er dårligere hos pasienter med schizofreni eller bipolar lidelse som samtidig har søvnproblemer, og at dette er relatert til insomni og hypersomni. Videre tyder resultatene på at behandling av søvnforstyrrelser er viktig for å bedre kognitiv funksjon hos denne pasientgruppen.

Do sleep disturbances contribute to cognitive impairments in schizophrenia spectrum and bipolar disorders?

Jannicke Fjæra Laskemoen, Camilla Büchmann, Elizabeth Ann Barrett, Margrethe Collier-Høegh, Beathe Haatveit, Trude Jahr Vedal, Torill Ueland, Ingrid Melle, Monica Aas, Carmen Simonsen

Publisert i European Archives of Psychiatry and Clinical Neuroscience

Sleep disturbances and cognitive impairments are both frequent across psychotic disorders, with debilitating effects on functioning and quality of life. This study aims to investigate if sleep disturbances are related to cognitive impairments in schizophrenia spectrum (SCZ) and bipolar disorders (BD), if this relationship varies between different sleep disturbances (insomnia, hypersomnia or delayed sleep phase (DSP)) and lastly, if this relationship differs between clinical groups and healthy controls (HC). We included 797 patients (SCZ = 457, BD = 340) from the Norwegian Centre for Mental Disorders Research (NORMENT) study in Norway. Sleep disturbances were based on items from the Inventory of Depressive Symptoms—Clinician rated scale (IDS-C). Their relationship with several cognitive domains was tested using separate ANCOVAs. A three-way between-groups ANOVA was conducted to test if the relationship with cognitive impairments varies between different sleep disturbances. These analyses revealed significantly poorer processing speed and inhibition in those with any sleep disturbance versus those without, also after adjusting for several covariates. The relationship between sleep disturbances and cognition was similar across SCZ and BD, and there were significant effects of insomnia and hypersomnia on both processing speed and inhibition. No association between sleep disturbances and cognition was found in HC. Sleep disturbances contribute to cognitive impairments in psychotic disorders. Processing speed and inhibition is poorer in patients with sleep disturbances. Impairments in these domains are related to insomnia and hypersomnia. These findings suggest that treating sleep disturbances is important to protect cognitive functioning, alongside cognitive remediation in psychotic disorders.