Recent systematic review s have shown that  light therapy  is an efficacious and well-tolerated treatment for SAD .
There is also evidence for efficacy of pharmacotherapy to treat and prevent SAD .
SAD is a common condition with significant psychosocial impairment .
BACKGROUND Seasonal affective disorder ( SAD ) consists of recurrent major depressive episodes in the fall/winter with remissions in spring/summer .
RESULTS A careful history is important to make the diagnosis and differentiate SAD from other similar conditions such as subsyndromal SAD and atypical depression .
Seasonal patterns with winter worsening are also recognized in " nonseasonal " depression as well as many other psychiatric conditions , and comorbidity with SAD is common .
The pathophysiology of SAD seems to be heterogeneous as research on circadian , neurotransmitter function and genetic hypotheses have shown discrepant results .
A dual vulnerability model with differential loading on separate seasonal and depression factors has been proposed to explain these findings .
Hypericum in the treatment of seasonal affective disorders.
Seasonal affective disorder ( SAD ) represents a subgroup of major depression with a regular occurrence of symptoms in autumn/winter and full remission in spring/summer . Light therapy ( LT ) has become the st and ard treatment of this type of depression . Apart from this , pharmacotherapy with antidepressants also seems to provide an improvement of SAD symptoms . The aim of this controlled , single-blind study was to evaluate if hypericum , a plant extract , could be beneficial in treating SAD patients and whether the combination with LT would be additionally advantageous . Patients who fulfilled DSM-III-R criteria for major depression with seasonal pattern were r and omized in a 4-week treatment study with 900 mg of hypericum per day combined with either bright ( 3000 lux , n = 10 ) or dim ( < 300 lux , n = 10 ) light condition . Light therapy was applied for 2 hours daily . We found a significant ( MANOVA , P < .001 ) reduction of the Hamilton Depression Scale score in both groups but no significant difference between the two groups . Our data suggest that pharmacologic treatment with hypericum may be an efficient therapy in patients with seasonal affective disorder
Recent systematic review s have shown that  light therapy  is an efficacious and well-tolerated treatment for SAD .
There is also evidence for efficacy of pharmacotherapy to treat and prevent SAD .
SAD is a common condition with significant psychosocial impairment .
BACKGROUND Seasonal affective disorder ( SAD ) consists of recurrent major depressive episodes in the fall/winter with remissions in spring/summer .
RESULTS A careful history is important to make the diagnosis and differentiate SAD from other similar conditions such as subsyndromal SAD and atypical depression .
Seasonal patterns with winter worsening are also recognized in " nonseasonal " depression as well as many other psychiatric conditions , and comorbidity with SAD is common .
The pathophysiology of SAD seems to be heterogeneous as research on circadian , neurotransmitter function and genetic hypotheses have shown discrepant results .
A dual vulnerability model with differential loading on separate seasonal and depression factors has been proposed to explain these findings .