David Baxter PhD
Late Founder
Gender influences age of bipolar onset
22 February 2005
Psychiatry Matters
Researchers have found gender differences in the incidence and age at onset of mania and bipolar disorder, with men affected earlier than women.
"Despite clear gender differences in the symptoms and course of bipolar affective disorder, studies investigating age at onset by gender have yielded inconsistent results," note Noel Kennedy, from the Institute of Psychiatry in London, UK, and colleagues.
For their study, published in the American Journal of Psychiatry, the team identified all cases of first-episode psychosis, mania, or hypomania in adults presenting to services in Camberwell, southeast London, between 1965 and 1999.
This included 246 patients who met the criteria for DSM-IV bipolar I disorder, first manic episode, of whom 141 (57%) were female, while the remaining 105 (43%) were male.
The average age at onset of mania was 32.9 years, with onset occurring earlier in men than in women, at an average age of 30 years versus 35 years.
Indeed, almost half of the male patients experienced their first episode of mania by the age of 25 years, and 80% by the age of 35 years. In comparison, only one-third of the female patients had experienced mania by the age of 25 years, and just 64% by the age of 35 years.
Similarly, the onset of bipolar disorder occurred in 56% of men by the age of 25 years and in 83% by the age of 35 years, compared with 37% and 68% of women, respectively.
The researchers note that the incidence of first manic episode peaked in men for the 16 to 25-year age group, whereas for women the incidence was lower in this age group, it was higher throughout the rest of adult life in women than for men.
Further analysis also revealed that childhood antisocial behavior was independently associated with earlier onset of mania and bipolar disorder. This led Kennedy et al to speculate that there may be a "subgroup of early-onset predominantly male bipolar disorder patients with behavioral difficulties."
They explain: "Antisocial behavior in childhood could be a manifestation of neurodevelopmental abnormality or even of early-onset bipolar disorder."
Am J Psychiatry 2005; 162: 257-262
22 February 2005
Psychiatry Matters
Researchers have found gender differences in the incidence and age at onset of mania and bipolar disorder, with men affected earlier than women.
"Despite clear gender differences in the symptoms and course of bipolar affective disorder, studies investigating age at onset by gender have yielded inconsistent results," note Noel Kennedy, from the Institute of Psychiatry in London, UK, and colleagues.
For their study, published in the American Journal of Psychiatry, the team identified all cases of first-episode psychosis, mania, or hypomania in adults presenting to services in Camberwell, southeast London, between 1965 and 1999.
This included 246 patients who met the criteria for DSM-IV bipolar I disorder, first manic episode, of whom 141 (57%) were female, while the remaining 105 (43%) were male.
The average age at onset of mania was 32.9 years, with onset occurring earlier in men than in women, at an average age of 30 years versus 35 years.
Indeed, almost half of the male patients experienced their first episode of mania by the age of 25 years, and 80% by the age of 35 years. In comparison, only one-third of the female patients had experienced mania by the age of 25 years, and just 64% by the age of 35 years.
Similarly, the onset of bipolar disorder occurred in 56% of men by the age of 25 years and in 83% by the age of 35 years, compared with 37% and 68% of women, respectively.
The researchers note that the incidence of first manic episode peaked in men for the 16 to 25-year age group, whereas for women the incidence was lower in this age group, it was higher throughout the rest of adult life in women than for men.
Further analysis also revealed that childhood antisocial behavior was independently associated with earlier onset of mania and bipolar disorder. This led Kennedy et al to speculate that there may be a "subgroup of early-onset predominantly male bipolar disorder patients with behavioral difficulties."
They explain: "Antisocial behavior in childhood could be a manifestation of neurodevelopmental abnormality or even of early-onset bipolar disorder."
Am J Psychiatry 2005; 162: 257-262
