Swaab, D.

study state depression research health disorder heritability department patient depressive disorder journal university level factor psychology emotion amsterdam netherland genetic cancer measure american journal pathway influence mayo clinic review depressive loneliness happiness psychiatry center anxiety system life satisfaction boomsma effect cortisol well-being heritability estimates chromosome example optimism serotonin cortisol levels difference personality family nucleus science neuroticism variance linkage association bartel stress polymorphism evidence outcome adult trait satisfaction american institute estimate epidemiology medicine activity clinic analysis variant relationship quality share finding treatment program heritable dopamine brain insight