Prevalence

of Seasonal John

M. Booker,

Affective Ph.D.,

Disorder

in Alaska

J. Hellekson,

and Carla

M.D.

Objective: The goals of this study are to provide estimates of the prevalence of seasonal affective disorder in Alaska, to examine sociodemographic correlates, and to evaluate the relation between seasonal affective disorder and general depression. Method: A random sample of283 residents with the Seasonal

ofFairbanks who Pattern Assessment

Depression

(CES-D

Scale

criteria

for

seasonal

Scale).

affective

winter affective disorders prevalent among residents the CES-D Scale supported of seasonal

affective

Results:

disorder,

disorder

of depression in northern (AmJ Psychiatry 1992;

The

rise

of

darkness,

cold,

and

isolation

Twenty-six one

of the

from

next

-Dr.

other

depression.

Cook,

circa

then

drive

the mental

1897

(1, pp. 113,

115)

S

easonab changes in mood and energy have long been accepted as a feature of life in the far north, and Dr. Cook was one of the early medical observers who described such effects. With the introduction of the diagnosis of seasonal affective disorder (2, 3), questions about the incidence and prevalence of seasonal mental health problems have been raised. This study provides estimates of the prevalence of seasonal affective disorden in Alaska, examines sociodemographic correlates, and evaluates the relation between seasonal affective disorder and general depression.

BACKGROUND Seasonal affective disorder sonal pattern, in DSM-III-R)

Received

Sept.

Jan. 24, 1992.

8, 1989;

From

revision

the School

versity of Alaska Anchorage. son, Eastside Group Health, 98052. Copyright © I 992 American

1176

(major has been

received

of Nursing

Dec.

depression, characterized

30,

and Health

Address reprint requests 2700 152nd St., N.E., Psychiatric

of the figures

subjects

yet

met

reported.

diagnostic These

cyclic

Conclusions:

This

study

supports

the

communities. 149:1176-1182)

year.

Frederick

(9.2%) highest

or more were interviewed for Epidemiologic Studies

disorder is prevalent in northern populations and that sex risk factors that differentiate it from the general experience

on to melancholy . . . . The earliest effects become in the mental realm. The physical changes become slowly, often not at all until near the end or at sunthe

for 3 years the Center

occurred more often in women than men (ratio=3:2) and were less who were older than 40 years ofage. Assessment ofdepression with the diagnostic classification ofrespondents and the differentiation

conclusions that seasonal affective and age may represent the major

faculties manifest evident

had lived in Alaska Questionnaire and

Association.

1991;

seaby

accepted

Sciences, to Dr. Redmond,

UniHellekWA

onset during autumn of depressive symptoms with an atypical pattern, featuring hypersomnia, irritability, weight gain, and carbohydrate craving. Among clinical populations the syndrome is more common in women, in a ratio of about 4:1 (4), which is higher than the 2:1 ratio noted in depressive illness in general (5). Clinical histories of patients receiving phototherapy for seasonal affective disorder suggest that depressive episodes last longer the farther north the patients live (4). In a random mail survey of 400 New York City residents (6), seasonal symptoms were common among the 193 respondents. Wintertime fatigue was reported by 50%, winter weight gain by 47%, increased sleep by 42%, and decreased social activity by 31%; 31% of the respondents said they felt worse in the winter. Among the 383 subjects who responded to a telephone survey of 416 randomly chosen residents of Montgomery County, Md. (7), seasonal affective disorder was estimated at 4.3% (71% female) and subsyndromal seasonal affective disorder (milder complaints) at 13.5% (55% female). Clinical interviews with a 10% subsample of the respondents revealed that the designations of no seasonal affective disorder, subsyndromal seasonal affective disorder, and seasonal affective disorder were consistent with levels of depression measured with the Hamilton Rating Scale for Depression (8, 9). A random mail survey of 1,576 residents at four different latitudes in the United States (10) produced estimates for seasonal affective disorder ranging from 1.4%

sponse 60.5%.

in Sarasota,

rates

Fla.,

for

Am

the

]

to

four

Psychiatry

9.7%

sites

in Nashua,

ranged

1 49:9,

from

September

N.H.

40.1

Re-

% to

1992

JOHN

Clinical Alaska

studies

of

been

completed,

have

have

been

available

of 64#{176} north, sonal

contrasts.

Available

the depression.

42

is 21

opportune

relation

at winter minutes,

daylight

provides

to assess and

daylight and

available

This

disorder

in

no epidemiologic data 1 1 ). Fairbanks lies at a latitude an environment of extreme sea-

(4,

3 hours the

utes.

affective

but

presenting

approximately solstice

seasonal

hours

49

under

extreme

is

at summer and

conditions

between

solstice

but

mm-

seasonal

in

higher

changes

BOOKER

self-administered threshold

underestimating disorder. However, criteria

will

for

the

prevalence prevalence

Subjects

General depression was Center for Epidemiologic (CES-D Scale) (14). This

based

on

tered

from

tistage

standardized

or older) tion=75,000). military

bases,

on

nursing

Fairbanks, subjects

university

homes,

tion,

only

those

for

3 years

or

exposure

to

seasonal

pattern

(The

response

rate

were

respondents seasons of related

there to symptoms.

in the

of

86%

populaliving on

had

lived

to

ensure

establish The

interviews

interviewed subjects

310

(total were

of

years

within

included.

included

a mul-

(21

or

not

who

were

who participated of all respondents

Alaska who

to

estimates

based

on

tionnaire

the

two

back

original

360

calls represented

a

household

(12,

pendent validation

at the

13).

measures of the

of use in

more, prevalence tern Assessment by

(6, seasonality

feeling

and 4=extremely of scores was linked

with

combined

which

1=mild

and

fective

Am]

to group

disorder,

Psychiatry

and

inde-

Further-

Seasonal expected

in this

Patvan-

study

Seasonal changes

sleep

length,

social

of the

symptoms 4=disabling.

respondents

those

149:9,

activ-

and energy level. Each of these a S-point scale on which 0=no

assessment

those

severity two with

subsyndromal

September

potential scores of com-

a S-point

These into

with

on

1992

affective on both

over

been used its validity

populations

(16).

the

pre-

effectively has been The

self-ad-

shown to correlate Rating Scale for

Affective

scale items

Disorder

(used

by the

shown met

higher

(used analysis global

in table criteria

self-administered

seasonality

category

der

(table

on

tests)

score.

of the

seasonal

Fairbanks

affective

criteria for A chi-square

of subsyndromal

respon-

disorder

subsyndromal test of

proportions for the two classification significant (table 1), indicating that the two global seasonality score criteria limits of random variation. The higher to the bower global seasonality score the

assignment based

in telephone surveys) are will be based on groups

1, 9% for

19% met disorder.

in the

resulting Estimates

and

seasonal hypothesized

schemes was not estimates for the were within the rates according value came from

seasonal

affective

disor-

1).

was

Pattern Asin mood

marked change. The 0 to 24. Global seasonality

an

of the

used

rural

threshold

another affective

of Mental

(10). the the

used

on the regarding

of well-being),

appetite, rated on

plaints

on show

score

(overall

were

Ques-

7, 10).

from six questions Questionnaire

change range

studies based

symptoms

Scale has (15), and

ofSeasonal

higher

dents

have provided initial Pattern Assessment

epidemiologic

derived sessment

ity, weight, items was

interviews

estimates Questionnaire

latitude

global

Institute

clinical

depression of the Seasonal

disorder

Assessment

National

Follow-up

Questionnaire

The

depressive

CES-D studies

with

defined

affective

Pattern

the

measured with the 20-item Studies Depression Scale scale assesses the presence

Table I reviews the criteria and of the subjects to diagnostic groups. the

Disorder

seasonal

Seasonal

developed

Health

ation

of

of seasonal estimates based

CES-D Scale has been well with the Hamilton (14).

Prevalence

As Population

chose potentially

RESULTS

sufficient a repeated 283 subjects

after interviewed

Affective

We thus

in Alaska

91%

of Seasonal

(7).

analyses,

Depression

and the lower threshold presented. Subsequent

Measurement

were

General

of

The

demonstrated

hos-

contacts.) The

frequency

ministered moderately Depression

our

In addi-

represented

the

of

vious week. in cross-ethnic

adult

campuses,

etc.,

more the

(N=310).

of 283

and

adminis-

mid-March

sample

of Potential

affective dishealth survey

interviews

through

probability residents

of seasonal community

household

mid-January

area

pitals,

prevalence a larger

HELLEKSON

be compared.

Measurement

study of the was part of

J.

CARLA

surveys

value

METHOD

This order

AND

fective disorder, and those with no seasonal affective disorder (normal subjects). Differing threshold values for global seasonabity score have been used; a global seasonality score of 10 or more has been applied in some telephone surveys, but a global seasonality score of 1 1 or more has been used

which

M.

on were

seasonal

af-

seasonal

af-

Individual

Characteristics

Univaniate

comparisons

characteristics groups

are

of given

the

of subjects

in table

2. The

the in

sociodemographic the

three

proportion

diagnostic of women

in each group, although lower than that reported for clinical populations, was significantly higher in the groups of subjects with seasonal affective disorder and subsyndromal seasonal affective disorder than in the group

of normal

subjects.

No statistically significant differences ethnicity; the prevalence of seasonal

were affective

found for disorder

1177

SEASONAL

AFFECTIVE

TABLE

DISORDER

1. Prevalen cc of Seasonal Seasonal

Thresholda Higher

Lower

IN ALASKA

Affective

Disorder

Affective

Disorder

Criteriab threshold

Global score1 plaints

threshold

Global

seasonality I and cornrated 2

seasonality

score10 plaints

in 28 3 Residents

of Fairbanks, Subsyndromal Affective

N

%

26

9.2

28

Alaska,

Seasonal Disorder

Criteria1’ Global seasonality score1 1 and complaints rated

9.9

score10 plaints

No Seasonal Criteriab

54

19.1

Global severity score