UNIPOLAR DEPRESSION

Unipolar depression, also more commonly known as "major" or "clinical" depression, is so called in order to distinguish it from bipolar disorder, to which it is closely related: a person is deemed to be afflicted by bipolar disorder when periods spent suffering from the same symptoms as someone who is clinically depressed are punctuated by bouts of mania. The terminology clearly relies on the view of mood states resting on a linear scale whose extremes are major depression and mania, with "normal" moods to be found inbetween.

A diagnosis ofunipolar depression is made on the basis of the display of five from the following list of sypmtoms for more than two weeks (either symptom one or two must be one of the five):

1. Sad, depressed mood.
2. Anhedonia (inability to enjoy activities normally enjoyed).
3. Difficulty in sleeping OR excessive sleeping.
4. Lethargy OR agitation.
5. Appetite/weight loss OR gain.
6. Loss of energy, fatigue.
7. Low self-esteem, feelings of worthlessness and guilt.
8. Difficulty in concentrating.
9. Recurrent thoughts of suicide.

Here I have paraphrased the actual words of the official diagnostic manual (DSM IV). The apparent repetition, lack of clarity (i.e. what constitutes difficulty in concentrating), and apparent covering of opposites by symptoms 3,4 and 5, show either that the diagnostic category is ill-defined or that the condition is hard to recognize/distinguish from "normal" types. A combination of the two explanations probably gets closer to the truth. Suffice it to say that the best diagnosis in this case is often made by the patient him/herself - if you are suffering from unipolar depression, you know about it: it can be extremely debilitating.

Studies show that between 1 in 20 and 1 in 10 people do know about it at some point during their lives. It is a recurrent disorder, to which people of a lower socioeconomic status and women are more prone (proof if proof were needed perhaps that money can make you happy). Success does not make you immune, however, and one way in which clinical depression can be easily distinguished from natural depression (following a death, etc.) or depression associated with other psychological problems, is that the sufferer really has nothing to be depressed about - there are a large number of celebrities who have suffered from unipolar disorder, for example, Jim Carrey, who has suffered from unipolar depression.

Before discussing the two most popular approaches to treating depression, namely cognitive therapy and drug therapy, I should at least pay lip service to other methods: psychoanalysis, based on the works of Freud or Jung, or other such luminaries, has generally been discredited, takes forever, and is often unsuccessful. electroconvulsive therapy (ECT), popularized earlier this century, is still used in cases of severe depression when all else has failed. Psychodynamic therapy, which focuses on the patient's interpersonal behaviour (social skills), can be thought of as a subset of cognitive therapy.

COGNITIVE THERAPY

The cognitive theory of depression can be seen as a formalisation/elaboration of the idea that people are depressed because they seem to "see the worst in everything". Aaron Beck, a pioneer of this approach in the sixties, suggested a three component model of the depressive's mindset:

1. During childhood and/or adolescence, an individual may acquire "negative schemata", or maladaptive ways of thinking about events based on unpleasant experiences. These schemata, in turn, determine how that person reacts to future similar events: so a person who is unfairly blamed during childhood will develop a self-blame schema, causing her to blame herself for anything that goes wrong. Similarly someone with an failure-schema will never believe that they have succeeded.
2. These schemata are strengthened by certain cognitive biases, or distorted ways of reaching conclusions, such as
   • arbitrary inference (coming to a conclusion in the absence of evidence),
   • selective abstraction (focusing on the one amongst many pieces of evidence which confirms the negative schema)
   • overgeneralization (making a grand conclusion based on very little evidence)
3. These in turn strengthen the "negative triad", consisting of negative views of the Self, the Future and the World.

Beck proposed that the feedback loops between these components of the depressive mindset could be broken by getting the patient to recognize that his way of interpreting events does not correspond with reality. By offering alternative interpretations of the same event, the therapist highlights the patient's biased way of thinking, thus weakening support for the negative schemata. At the same time, the therapist urges changes in behaviour which may again help rectify negative ways of thinking.

The main recommendation for cognitive therapy is that depressive patients have been shown to have cognitive biases and negative schemata which can be quickly extinguished once addressed (typically in 4-6 sessions). With new ways of interpreting events, suggested by the therapist, the patient is cured, empowered and thus armed against any recurrence of the symptoms. The success of this approach has recently led the resource-deficient NHS to produce a so that people can "cure themselves", by understanding and using the theory outlined above.

DRUG THERAPY

Advocates of drug therapy support the biological theory of depression, which holds that it is caused by a deficiency of (a) certain type(s) of neurotransmitter in the brain. This theory is supported by the observation that (so-called "endogynous") depression can run in families, and by twin studies, which seemingly confirm that the problem has a genetic component. The genetic underpinnings of unipolar depression, and all other mental disorders for that matter, have not yet been identified, although part of the promise of the Human Genome Project is that they will be.

Serotonin is the neurotransmitter whose role in determining an individual's mood has recently been stressed above all others. Animal studies showing that subordinate monkeys, low in the social hierarchy, are deficient in it, compared to their dominant counterparts, are used as evidence that this is the case. A class of drugs known as Selective Serotonin Reuptake Inhibitors (SSRI's), of which fluoxetine, brand name Prozac, is the most well-known, optimize the function of delivery across synapses via serotonin by inhibiting its reuptake after a neuron has fired. Its success in treating unipolar depression is well-documented. There is a suspicion that it is over-prescribed, owing to the relatively mild side effects compared to those caused by previous antidepressant drugs (e.g. tricyclics and MOAI's). Some sufferers do claim to have been affected very badly by it, although it seems that most find it to be a God-send. However, despite claims that it is non-addictive, it may be mentally addictive, as many seem to find it hard to stop taking the drug without recurrence of symptoms - I suspect that this is likely because it is often used without any counselling to accompany it. Furthermore, there may be a psychological effect at work - if you began taking a pill because of a deficiency of a certain substance, why should the deficiency, and thus the symptoms, not reoccur?

Interestingly, Prozac seems to be the ideal partner for that other popular 1990's mood-altering substance, namely MDMA, or ecstasy, which floods the brain with serotonin when taken, but leads to damage of serotonin receptors with repeated use. Prozac is therefore clearly the best drug for those who experience mood disorders as a result of Ecstasy use.