Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.

To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.

Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.

Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.

AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.

We aimed to evaluate the prevalence, clinical determinants, and consequences (falls and hospitalization) of frailty in older adults with mental illness.

Retrospective clinical cohort study.

We collected the data in a specialized psychogeriatric ward, in Boston, USA, between July 2018 and June 2019.

Two hundred and fourty-four inpatients aged 65 years old and over.

Psychiatric diagnosis was based on a multi-professional consensus meeting according to DSM-5 criteria. Frailty was assessed according to two common instruments, that is, the FRAIL questionnaire and the deficit accumulation model (aka Frailty Index [FI]). Multiple linear regression analyses were conducted to evaluate the association between frailty and sample demographics (age, female sex, and non-Caucasian ethnicity) and clinical characteristics (dementia, number of clinical diseases, current infection, number of psychotropic, and non-psychotropic medications in use). Multiple regression between frailty assessments and either falls or number of hospital admissions in the last 6 and 12 months, respectively, were analyzed and adjusted for covariates.

Prevalence of frailty was high, that is, 83.6% according to the FI and 55.3% according to the FRAIL questionnaire. Age, the number of clinical (somatic) diseases, and the number of non-psychotropic medications were independently associated with frailty identified by the FRAIL. Dementia, current infection, the number of clinical (somatic) diseases, and the number of non-psychotropic medications were independently associated with frailty according to the FI. Falls were significantly associated with both frailty instruments. However, we found only a significant association for the number of hospital admissions with the FI.

Frailty is highly prevalent among geriatric psychiatry inpatients. The FRAIL questionnaire and the FI may capture different forms of frailty dimensions, being the former probably more associated with the phenotype model and the latter more associated with multimorbidity.