I now count it as a major life error that I didn't tell someone to try Prozac five years earlier.

For some people it doesn't work.

For others you see miracle-level improvements within days.

Just try it and see what happens.

Generic Prozac costs me $4 a month. It has improved my mood greatly over the course of two months. I was afraid of side effects at first. Then, during one bad period, I remembered what exactly it was I was trying to cure and decided all the side effects that regularly come with and more are worth not going through that anymore. So is taking this stuff for the rest of my life.

SSRIs have varying levels of withdrawal symptoms (Prozac's is low, Paxil's high).One study on SSRIs shows that for many people they are not more effective than a placebo, but for the most depressed people they are extremely effective. If your girlfriend has sever chronic depression, there's a good chance the condition is genetic, and there's no very good way to fix that aside from medicine.

Dependence on a drug that is cheap, has few side effects, and can almost completely cure chronic depression is a very small price to pay for never feeling as worthless as depression can make you feel. I'm sure you can find many, many more such testimonials. If the side effects bother her, she can change drugs--there are a lot of alternatives.

Advice in fighting depression?

Vigorous aerobic exercise, Cognitive Behavioral Therapy, antidepressants and nutrition (Omega 3 and a multivitamin) in approximately that order of expected effectiveness.

The SSRE tianeptine seems to be more tolerable than the more typical class, the SSRIs. If taking SSRIs be wary of venlafaxine and paxil - the withdrawal symptoms of those two are a nightmare. Of the SSRIs I recommend escitalopram as more effective and specific than Prozac without the side effects of the two previously mentioned.

She says she never want's to take antidepressants because she fears to get dependent from them. I

Who cares? The status quo sounds terrible, the risks are minimal and typical antidepressants are not addictive. The biggest problem with withdrawing from most antidepressants is that you often go back to the depressed state that you were in before you started. If (generic) you end up on antidepressants for your entire life and they work for you then great!

Have you seen this article I wrote? It is a non-drug-based depression-fighting story.

As someone who has struggled with severe depression for . . . hell, is it really twenty years already? . . . I have exactly one word of advice: Medicate.

I was suicidal, to the point of making quite efficient, detailed plans that I simply couldn't be bothered to actually implement. I was crying almost every day. I was unable to laugh. Now? Now I'm just a bit more melancholy than the average person.

I'm not exactly sure what she means by "dependent", but they are not addictive, they are not uppers, they are not "happy pills". They are, purely and simply, anti-depression.

By the way, reactions can be idiosyncratic. My doc tried me on a half-dozen antidepressants before they found one (actually, a pair, Luvox and Trazodone) that actually worked. (Well, Prozac worked, and very quickly, but also gave me hives. I actually argued with my doctor that the hives were worth it; she said the allergic symptoms could get worse and kill me.)

As others have said, SSRIs really help. And it may help to say - it's not a happy-pill. A lot of non-depressed people seem to think it's something you take that makes you happy. If you're feeling down they'll ask if you've stopped taking your medicine, because if you're on them you should be cheerful, right?

This is not a happy pill. It doesn't fundamentally change anything. But it takes the sharp edge off the pain so that it's bearable.

Therapy is surprisingly effective too.

Over the past decade+ I've also found that an ability to monitor and hack your own mood is an incredibly valuable skill. Know what things trigger depression and either avoid them or work out a contingency plan to weather the storm. I keep my driving after dark to a minimum because cityscapes at night do this to me. Have a mind-killer available for when a spiral is coming and force yourself to use it. Obviously some are healthier than others (great books often work well) but the really important part is to shut down that introspection quickly. The more you do it, the better you become at it.

I've been using Lexapro for some time and it has been great for me, without noticeable side effects.

I worried about relying on a drug for my happiness, but in the end I realized I needed to be more worried about being depressed than I did about being reliant on drugs.

As wedrifid said, if someone ends up taking drugs for the rest of their life, and that gets rid of their depression, great! Goal accomplished!

I think the big thing that helped me make the decision to pursue medication was all the smart technophiles that abound on Less Wrong. Realizing that using technology to make things better was the point of having technology in the first place, rather than trying to grunt and bear it myself.

General Point: Seek professional medical assistance as soon as possible.

In the UK general practitioners are very capable of dealing with it, and do so regularly, and can refer you to specialists if necessary, and in the short term supply medication. I assume the situation is similar where you are, (Germany?) as it is in all developed countries.

My personal experience is that putting off seeking professional assistance is one of the worst things I have ever done, it is an extremely difficult step to take but a necessary one that will help a lot. Unsurprisingly, people in extremely depressed states are not acting very rationally, and so prioritize things like social pressures, pride and so on above the need to get help. Particularly among intelligent people there is a strong cultural bias against seeking assistance, which is very harmful in this case.

In terms of treatment you can apply yourself. I have personally found that exercise is extremely helpful, walking at the very minimum and more strenuous exercise if possible (remember our brains are optimized to an ancestral environment of almost constant physical exercise). Also improving sleep patterns, healthier diet and reducing use of alcohol and caffeine can be helpful, though depend more on individual circumstances.

On medication, based on my personal experience and knowledge of the medical data I would strongly recommend it.

She says she never want's to take antidepressants because she fears to get dependent from them.

This is a worry shared by a lot of people, which while rational is based on a mis-perception of how depression and antidepressants work.

Roughly, we have a strong aversion to the idea of making people 'artificially' happy for whatever reason (see http://wiki.lesswrong.com/wiki/Wireheading). Probably justifiably. People generally associate depression with sadness, hence consider anti depressants as 'happy pills' and hence bad.

The mis-perception is that while depression can cause sadness it is not equivalent, depression itself is a physiological state of reduced and distorted brain activity, which results in an absence of natural emotional reactions, and hence feelings of detachment, low mood and self esteem. For a rough analogy, a healthy person should feel bad if bad things happen and good if good things happen, a depressed person would be indifferent to both.

Modern anti-depressants (SSRIs and SNRIs generally) work by enhancing neurotransmitter levels, and so allowing the brain to function more effectively and communicate signals better. Analogously to repairing a damaged processor on a computer so it works faster. (Disclaimer, I am not a Doctor and this is a simplification) From my personal experience I've found my brain works much better on medication, to the extent I can almost literally feel myself thinking faster, and while I still have bad periods I am capable of dealing with them. There are some minor adjustment side effects, but they are well worth it, and a doctor can guide you through them.

(Sorry the post ended up so long, hope it was helpful.)

We often go on walks to catch some sunlight and get her some exercise.

You might look into full spectrum lights as well. My father thought he might have some seasonal affective disorder going on and bought one. Take it for what it's worth, but wiki has some citations in the treatment section discussing the effectiveness of such treatments. They're a bit expensive (depending on your definition cutoff), but may prove to be easy and effective. I've read some on forums who turn it one while they eat breakfast in the morning.

My girlfriend suffers serious depression ... anorexia ... she considers herself very happy apart from the "depression periods"

The depression is very likely caused by some sort of dietary deficiency, and the depression periods are probably the periods when that deficiency is worst, so focus your attention on diet. If she isn't taking a multivitamin every day, fix that first. Then start keeping both a food log and a "daily mood" log. For the former, either write down everything eaten, or take a quick photo of it type up the log later using the photos. For the mood log, ask her to rate how she felt on a 1-5 scale and write it down at the end of each day. Then compare the two logs and look for patterns. Or publish the log and ask others to look for patterns.

Have you signed up to see the therapist? It sucks that you have to wait a month, but it sounds like this has been going on a lot longer than a month and it is likely to continue for a lot longer than a month, so it's worth going even if you have to wait a month.

So, I self-diagnosed as moderately depressive about a month ago, following a few months of an increasingly serious blue funk and greater than usual akrasia. Explicitly using the D word was an important factor in deciding to do something about it. Even so it took me a month to get off my butt and go see the family doctor, which I did today. She confirmed the diagnosis. Now that it's more or less official, I'm posting here to solicit advice and to offer data.

I have a prescription for Paxil, which I'm (provisionally, pending further info and/or advice) not intending to take, after reading up on undesirable side effects. All listings agree on the "sexual dysfunction" category, rated as "very frequent" - a probability of 15% to 60% depending on the studies. As a married man I see that as a showstopper. I also have a prescription for talk therapy, to which my response is "meh" - but I'll probably give it a try.

Any situation-specific advice on alternatives, or in general?

(N.B. I'll operate on the assumption that you're not a doctor and therefore not qualified to give medical advice, unless you state otherwise, so don't feel obliged to give that kind of disclaimer. Also assume I've read the rest of the comments here, and only repeat something if you think it's important enough to repeat.)

Is it very bad being dependent on antidepressants? What would the worrying downsides of dependency be?

Exercise is widely recommended.

As far as I know Cognitive-Behavioural Therapy is the closest to having an evidence base for success, although I couldn't point you to the studies.

Healthy eating is probably worth an effort, and of course good for all sorts of reasons.