Identifying more homogenous subtypes of patients with obsessive–compulsive disorder (OCD) using biological evidence is critical for understanding complexities of the disorder in this heterogeneous population. Age of onset serves as a useful subtyping scheme for distinguishing OCD into two subgroups that aligns with neurodevelopmental perspectives. The underlying neurobiological markers for these distinct neurodevelopmental differences can be identified by investigating gyrification changes to establish biological evidence-based homogeneous subtypes.

We compared whole-brain cortical gyrification in 84 patients with early-onset OCD, 84 patients with late-onset OCD, and 152 healthy controls (HCs) to identify potential markers for early neurodevelopmental deficits using the local gyrification index (lGI). Then, the relationships between lGI in clusters showing significant differences and performance in visuospatial memory and verbal fluency, which are considered trait-related neurocognitive impairments in OCD, were further examined in early-onset OCD patients.

The early-onset OCD patients exhibited significantly greater gyrification than those with late-onset OCD patients and HCs in frontoparietal and cingulate regions, including the bilateral precentral, postcentral, precuneus, paracentral, posterior cingulate, superior frontal, and caudal anterior cingulate gyri. Moreover, impaired neurocognitive functions in early-onset OCD patients were correlated with increased gyrification.

Our findings provide a neurobiological marker to distinguish the OCD population into more neurodevelopmentally homogeneous subtypes, which may contribute to the understanding of the neurodevelopmental underpinnings of an etiology in early-onset OCD consistent with the accumulated phenotypic evidence of greater neurodevelopmental deficits in early-onset OCD than in late-onset OCD.

The association between cigarette smoking and psychiatric disorders is well established for adult populations. However, only limited number of studies has investigated whether the young onset age of daily smoking (DS) among adolescents is associated with psychiatric morbidity and vice versa.

Data from 508 adolescents admitted to psychiatric hospitalization were collected. Cox proportional hazard model were used to compare the initiation of DS between adolescents with and without substance use (SUD), and other psychiatric disorders.

Rates of DS were high in each diagnostic category. Boys started smoking at younger age (mean 12.4 years) than girls (13.0 years). Both boys and girls diagnosed with conduct or oppositional defiant disorders (COD) and also girls with SUD started daily smoking earlier as compared to those of same gender without these disorders.COD were found to be primary to the initiation of DS among boys. SUD, psychotic, and depressive disorders (DEP) were found to be secondary to DS among both genders.

DS in adolescence is related with later SUD. COD are associated with subsequent initiation of DS among boys. The temporal gap between smoking initiation and COD is shorter among girls. Gender difference plays a role in association of DS and DEP. Initiation of DS at very early age should alert health care professionals of development of later psychopathology, especially SUD.

To study the association between age at onset and the clinical picture of schizophrenia in an unselected young birth cohort.

The study sample consists of 98 (64 males and 34 females) individuals with DSM-III-R schizophrenia collected from the Northern Finland 1966 birth cohort. Firstly, subjects were divided into very early- and young-onset subgroups by using the median age at onset (22 years in males and 20 in females), as a cut-off point. Secondly, we used age at onset as a continuous variable. Clinical features of schizophrenia were assessed using the Operational Criteria Checklist for Psychotic Illnesses (OCCPI).

Inappropriate affect, positive thought disorder and deterioration from premorbid level of function associate with very early-onset schizophrenia, while slowed activity and dysphoria relate to young-onset. These symptoms correlate significantly with the age at onset.

Differences in the clinical picture associating to the age at onset of schizophrenia are seen early.

These findings indicate that certain symptoms of schizophrenia are dependent on the age at onset, and schizophrenia occurring initially in early life has some typical features. Using the age at onset as a continuous variable is independent of arbitrary cut-off points and produces more explicable results.

Menarche age has been associated inconsistently with the occurrence, timing or severity of major depressive disorder (MDD), but rarely studied in women with bipolar (BDs) or anxiety disorders.

We investigated women patients at a Sardinian mood disorder center for associations of age at menarche with age at illness onset for major affective or anxiety disorders, year of birth, and other selected factors, using bivariate comparisons and multivariate regression modeling.

Among women (n = 1139) with DSM-IV MDD (n = 557), BD-I (n = 223), BD-II (n = 178), or anxiety disorders (n = 181), born in 1904–1998, of mean age 42.9 years, menarche age averaged 12.8 [CI: 12.7–12.9] years. Illness onset age averaged 30.9 [30.1–31.8] years, ranking: BD-I, 25.8; anxiety disorders, 28.0; BD-II, 30.3; MDD, 34.1 years. Menarche age declined secularly over birth years, and was associated with younger illness-onset, having no or fewer siblings, more psychiatrically ill first-degree relatives, living in rural environments, being suicidal, substance abuse, and being unemployed. Earlier menarche and earlier illness-onset were significantly associated for onset age groups of ≤ 20, 20–39, and > 40 years. Menarche age versus diagnosis ranked: BD-II < BD-I < anxiety disorders < MDD.

Age at menarche in Sardinia, as elsewhere, has declined over the past decades. It was strongly associated with age at onset of bipolar and anxiety, as well as major depressive disorders across the age range, suggesting sustained effects of biological maturational factors.