A community forum on depression and suicide prevention Tuesday night revealed a startling statistic: The number of suicide attempts on Martha's Vineyard has tripled in the last year compared to the incidence in the previous 12 months.

Dr. Timothy Tsai, director of emergency medicine at the Martha's Vineyard Hospital, told a panel of mental health practitioners and the crowd of people who attended the forum at the regional high school library that suicide attempts have climbed from less than 10 to nearly 30 over the course of the last two years.

In the same period of time, the number of patients at the hospital diagnosed with depression almost doubled, from 47 cases to roughly 90 cases, Dr. Tsai said.

"Depression is the major risk factor for suicide," panelist Susan Desmarais, an outreach worker for the Edgartown council on aging, said in her opening remarks to the audience of more than 30 people who gathered around tables in the school library for the two-hour session.

The statistical data only cemented the impetus behind this week's forum, sparked by a concern over an apparent increase in the number of suicides and a desire to raise awareness about depression on the Vineyard, where rates of the mental illness exceed the national average.

Judy Olson, a licensed clinical social worker from Edgartown and one of the panelists, said she was aware of six suicides on the Island in the last 18 months. Between 1994 and 2002, the Massachusetts Department of Public Health (DPH) counted no more than one or two suicides a year in Dukes County. In 1999 and 2001, no suicides were reported in Dukes County, according to the DPH figures.

If the recent figures are verified, Dukes County would likely outrank all other counties as the the highest suicide rate in the commonwealth.

While this week's forum centered on the basics, raising the veil on a difficult subject and trying to inform people of the symptoms of depression and the need to seek treatment, panelists and audience members also grappled with the deeper and more troubling question of why so many Islanders are depressed and why some have gone to the brink of taking their own lives.

There was at least one obvious factor: alcohol consumption.

The Island Health Report, a comprehensive health survey completed last year by a coalition of health organizations on the Vineyard, found that roughly one-tenth of year-round Island residents consume five or more drinks in one sitting at least twice a month, behavior that the federal Centers for Disease Control define as problem drinking. That rate is also significantly higher than the national average, according to the health report

Jane Dreeben, a psychologist from Vineyard Haven who was part of the panel, pointed out the dangerous link between mental illness, suicide and substance abuse, saying that regular alcohol use can not only cause depression, it can also mask or medicate its symptoms. Consistent drinking can also pave the way for people to act impulsively when they are confronted with stress or difficult feelings.

"Regular alcohol use can also cause anxiety," said Ms. Dreeben.

The problem of depression can be more acute for both adolescents and the elderly, said two panelists who specialize in treating those age groups. Amy Lilavois, a counselor in Vineyard Haven who works almost exclusively with teenagers, said suicide is one of the leading causes of death for adolescents.

"For a teenager, everything is overwhelming. There are so many new things happening," she said.

On the other side of the spectrum, Ms. Olson said the Island's older residents are at a high risk for depression. "A major precipitant to depression is loss. And many have lost their health, their independence. They're not driving anymore. It contributes to isolation and more so in a rural community," she said.

The statistics about suicide attempts and depression cases were simply raw data, which Dr. Tsai had not analyzed to break down trends of age or gender, but he told the Gazette this week that he plans to look more closely at the demographics and share the findings.

Lacking precise data, no simple answers emerged to the question of why depression rates on the Island are high, but there was some speculation about underlying reasons specific to the Vineyard.

"Economic hardship is a contributing factor," said Ms. Olson.

Tom Bennett, the program director at Island Counseling Center at Martha's Vineyard Community Services, suggested that the social difficulties posed by Island life might play a role.

"Because this is such a small community, when people make mistakes their sense of shame is magnified. People think they can't get through it," he said.

Two members of the audience agreed that the Vineyard's image as a close-knit community is not always an accurate reflection of reality.

"It's a misconception to say we're close knit," said one woman, describing herself as a third generation Islander. "There's a big hype in our reputation that we're really special and this is the best place to be but we're not quite as homogeneous as we think. There are many different little groups here and a great deal of isolation. There's a lot of loneliness."

Mental health practitioners also expressed concern about the contagious effects of depression, and suicide attempts in particular, in the Island community. Ms. Lilavois noted that among teenage girls, self-mutilation, or cutting as it's also known, can spread through a group of friends.

The second half of the forum focused on solutions to the problem. Identifying symptoms and seeking help were key among them. Persistent feelings of sadness, anxiety and emptiness along with sleep disturbances - either too much or too little - are also chief signs of depression. Weight loss or excessive weight are other symptoms, said Ms. Desmarais.

If someone has lost interest in activities they once enjoyed, that can be another sign. The mental illness known bipolar disorder is characterized by sharp mood swings, from feeling very down to feeling energetic and hyper-confident.

Panelists recommended that in addition to seeking medical treatment and meeting with a mental health counselor, there are other effective treatment options including anti-depressant medication. Oceana Rames, a naturopathic physician from West Tisbury, stressed the importance of diet and exercise as ways to help ward off feelings of depression.

"Exercise is as important as any medication you take," said one panelist.

Ms. Dreeben urged people to raise the issue of depression with friends and loved ones, not to shy away from the topic. "Put the topic on the table, make it speakable. You can ask them, 'Are you thinking about suicide?'" she said.

"Ask them, 'Would you be willing to talk to someone about this in addition to me?'" she added.

Rufus Peebles, a psychologist from West Tisbury, reminded people of the Island's active 12-step programs. "They give people a sense of connection, of family," he said.

Dr. Tsai's alarming data seemed to linger in the room as the discussion unfolded, fresh and hard evidence that the health report completed last summer had pinpointed a serious mental health problem faced by Islanders.

Panelists agreed it is not an easy subject to air in public, but the risks of remaining silent about depression are great. That was very clear when a woman stood up and said: "I suffer from depression and have since childhood. It's a secret sickness, and while the issue of anonymity is important, we're also protecting the very people who need to be talked about."