Age-at-Onset of 648 Patients with Major Affective Disorders: Clinical and Prognostic Implications

Major affective disorders are highly heterogeneous in their clinical presentations, longitudinal course, risk of disability and mortality, and responses to treatment. Age-at-onset is a relatively simple and objective indicator reported to vary among patients with specific types of mood disorders. Onset-age may have value as a correlate or predictor of particular clinical or biomedical features of specific types of mood disorders and young onset-age has been proposed specifically as an indicator of relatively great familial or genetic risk and of adverse long-term outcome.

Abstract

BACKGROUND AND OBJECTIVE

Onset-age reportedly differs among affective disorders and may be a simple, objective means of supporting diagnosis, prognosis, and treatment-selection. We compared onset-age in Argentine patients diagnosed with the Diagnostic and Statistical Manual of Mental Disorders 4th ed. (DSM-IV) major mood disorders (bipolar [BPD] types I, II, or unspecified [NOS], or unipolar-major depressive disorder [UP-MDD]).

METHODS

Adult patients (n=648) were diagnosed with a DSM-IV-TR BPD (243 type-I, 199 type-II, and 88 NOS), or UP-MDD (118) and skewed onset-age distributions were compared nonparametrically. We also examined associations of onset-age with demographic and clinical characteristics, tested the ability of onset-age to distinguish BPD from UP-MDD patients, and predicted later morbidity or disability.

RESULTS

By diagnosis, onset-age (median with interquartile range [IQR]) ranked: BP-I (25.0 [14.0])=BP-II (25.0 [15.8])<bpd-nos></bpd-nos>

DISCUSSION

Onset was younger among BPD than UP-MDD patients, generally confirming recent findings in other world regions. Older onset was associated with some functional outcomes (marriage and work) but not an index of morbidity (recurrence rate), suggesting a complex relationship to later illness-course and disability.

Keywords

age-at-onset, bipolar disorders, unipolar major depressive disorder