Related Experiment Video
Updated: Oct 31, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Seasonal sensitivity and psychiatric morbidity: study about seasonal affective disorder
Aníbal Fonte1,2,3, Bruno Coutinho4
1Department of Psychiatry and Mental Health / Local Health Unit of the Alto Minho (ULSAM, EPE), Hospital de Santa Luzia, Estrada de Santa Luzia, 4901-858, Viana do Castelo, Portugal. afonte@mail.telepac.pt.
Background:
Seasonal Affective Disorder is a recurrent depressive disorder which usually begins in the fall/winter and enters into remission in the spring/summer, although in some cases may occur in the summer with remission in the autumn-winter. In this study the authors evaluated the association between seasonal changes in mood and behavior with psychiatric disturbance.
Method:
Descriptive, cross-sectional study. Participants, students attending higher education and vocational courses (N = 324), were evaluated with the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Screening Scale for Mental Health (ER80).
Results:
Among the respondents, 12.7% showed seasonal affective disorder (SAD), 29.0% showed subsyndromal seasonal affective disorder (s-SAD) and 58.3% did not show significant seasonal affective symptomatology. As for psychiatric morbidity, 36.6% of subjects with SAD and 13.8% of those with s-SAD were considered "psychiatric cases" whereas for subjects without SAD this value was only 3.2%.
Conclusions:
There is a statistically significant association between psychiatric morbidity and seasonal affective disorder. This association corroborates the importance of the Seasonal Pattern Assessment Questionnaire in screening for seasonal fluctuations in mood and behavior related disorders, and the clinical need for recognition of these conditions, particularly associated suffering and disabilities.
Related Concept Videos
Depressive Disorders: MDD and Dysthymia
Bipolar Disorder
Depressive Disorders: Etiology
Biological Factors in Depression
Biological predispositions significantly influence the risk of developing depressive disorders. Genetic studies highlight the role of variations in the serotonin transporter...
Biological Clocks and Seasonal Responses
Diagnostic and Statistical Manual of Mental Disorders (DSM)
Autism Spectrum Disorder
These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.

