Anxiety can become progressively disabling at work and in personal relationships. Anxious people have frequent feelings of guilt and worthlessness about not being able to cope successfully with situations that other people have no difficulty with and about being dependent on family and friends, thereby restricting their lives.

The longer anxiety persists without effective treatment, the more likely it is that those who suffer will become depressed. As anxiety becomes progressively more disabling, it can significantly hamper the ability to live a full and enjoyable life.

Anxiety and depression frequently occur in tandem. Irritability, difficulty concentrating, indecision, guilt, fatigue, sleep and eating disturbances, and chronic aches and pains are symptoms common to both disorders. In particular, agoraphobia and depression are closely linked.

Almost half of the people who suffer repeated panic attacks develop a major case of depression. Low levels of serotonin have been implicated in both anxiety disorders and depression. Many studies have found that selective serotonin reuptake inhibitors (SSRIs), such as Prozac (fuoxetine), Paxil (paroxetine), and Anafranil (clomipramine), are useful in treating both anxiety and depression. The natural antidepressant herb Saint-John’s-wort can be effective not only for depression but also for anxiety.

Clinical depression is different from the pain that immediately follows a loss and from the down cycle in life’s ordinary ups and downs. Nor does clinical depression reflect the popular use of the word which usually means feeling disappointed or temporarily dejected.

There are three major forms of clinical depression:

Major Depression: Like pneumonia, major depression has a beginning, a middle, and an end. Untreated, the average episode of major depression lasts six months, and it can return periodically for an average of five to six episodes in a lifetime.

Dysthymia (chronic depression): If a depression is experienced most of the day, more days than not, for more than two years, it’s known as dysthymia. Dysthymia lasts more than fve years on average if it goes untreated.

Manic-depression (bipolar illness): Here the lows of depression can alternate with extreme elation, unreasonably grandiose thoughts, sleeplessness, hyperactivity, and inappropriate, sometimes destructive actions. Manic episodes return more or less regularly unless they are treated. People who suffer from clinical depression have significant amounts of physical, psychological, and occupational disability.

Depressive symptoms may also occur under specific circumstances, such as seasonal affective disorder (SAD), premenstrual syndrome (PMS), postpartum blues or depression, and bereavement (melancholia), as a consequence of drug and alcohol abuse, and as a result of medical conditions like low thyroid disease.